Seedtag

We’re looking for a Backend Software Engineer - AdExchange to join our tech team and help build the future of neuro-contextual advertising at global scale. Who We Are At Seedtag, our mission is to transform advertising by proving that effectiveness and user privacy can truly coexist. As the leading Neuro-Contextual Advertising Company, we combine Artificial Intelligence, Natural Language Processing, Computer Vision, and neuroscience to understand not only what content is about, but how it makes people feel and what they intend to do next. Our proprietary AI, Liz, enables brands to connect with audiences across the open web and Connected TV without cookies or user tracking. Founded in 2014 by two ex-Googlers, Seedtag has grown to 700+ Seedtaggers in 17 countries, backed by €250M in funding, and operates today as a global ad-tech leader. If you enjoy solving complex engineering challenges and building AI-driven systems at scale, you’ll feel right at home here. Your Challenge You will be architecting, refining and developing the backend services that power our AdExchange. In an industry where milliseconds determine success, you will focus on: - Optimising the high-throughput real-time bidding systems where you'll balance ultra-low latency requirements with cost-efficiency and reliability, ensuring our infrastructure scales sustainably. - Integrating new demand partners, owning the full lifecycle from capacity planning and endpoint configuration to traffic shaping and performance validation. - Designing pricing and auction mechanics, including bid flooring systems and dynamic margin calculations, serving machine learning models in real-time to optimise revenue. - Building event pipelines and reporting integrations that enable data teams to analyse performance, debug issues, and feed AI models. - Working on end-to-end projects from concept to production, making technical decisions, managing priorities, and communicating effectively with stakeholders across the company. - Collaborating closely with cross-functional teams with a data-driven analytical mindset, validating hypotheses with real data and aligning engineering work with business goals. This is a high-impact challenge that will shape the future of Seedtag. If you are up to the challenge and want to be a part of a talented and passionate team, we encourage you to apply for this position. Our Core Values Outcome over Output We measure success by impact and value, not by volume of features or lines of code. Failure Is Allowed, Learning Is a Must Experimentation is key to innovation. We test early, iterate often, and learn fast. We Are All Scouts We take ownership and leave things better than we found them. We Are Data-Driven Data informs our decisions and helps us continuously improve our systems and results. Tech Stack - We use Go, Typescript, Python, Mongo, Redis, Google Cloud, Kafka... - We craft high-throughput ⚙ micro-services, APIs, data pipelines, async message queues… - We breathe DevOps, love Kanbans, Pair Programming, Peer Reviews, Continuous Discovery, Delivery and Integration. - We are on Slack, Notion, JIRA, and GitHub. What You’ll Need to Succeed - You have a deep understanding of back-end development. You have at least 5 years of demonstrable experience working in software engineering, with a focus on building back-end systems. You have experience using it to build scalable, high-performance systems. - You care about producing maintainable code over time using good programming practices. You have experience applying programming patterns. - You have experience with high-throughput systems and distributed architectures. You are comfortable working with systems that handle large amounts of data and have experience building systems that scale to meet demand. - AI-Augmented Productivity: You embrace AI tools (GitHub Copilot, Claude code, LLMs, etc.) as a fundamental part of your daily workflow. You understand how to leverage these tools to speed up boilerplate coding, debugging, and learning, allowing you to focus on high-level architecture and complex problem-solving. - You are a big-picture thinker who can see the forest and the trees. You have a strong understanding of the technical and business requirements of the projects you work on, and you can think strategically to ensure that your work aligns with the goals of the company. - You are a problem solver who loves a good challenge. You are energised by tackling complex technical problems and figuring out creative solutions. - You are a continuous learner who is passionate about your craft. You are committed to staying up-to-date with the latest developments in back-end engineering and are always looking for ways to improve your skills and knowledge. - You are a strong communicator who can work effectively in a team. You are comfortable working collaboratively with others, and you are able to effectively communicate complex technical concepts to both technical and non-technical stakeholders. If you possess these qualities and are excited about the opportunity to work on challenging, high-impact projects with a talented and passionate team, we encourage you to apply for this position. Why Join Seedtag? - A key moment of growth with real ownership and global impact. - Flexible work model with 100% remote or hybrid options. (Remote contracts available in Spain, Italy, UK, Belgium, Netherlands, France, and Germany.) - Continuous learning through a learning platform and optional language classes. - A supportive, trust-based culture that values well-being. - Team activities, offsites, and opportunities to connect beyond work. Additional Perks - Home office setup budget up to €1,000 - Paid trips to our HQ in Madrid - MacBook Pro M3 Ready to Join the Seedtag Adventure? At Seedtag, we create an environment where everyone can thrive. If you need accommodations during the hiring process, let us know and we’ll ensure a positive experience. Send us your CV and let’s build the future of neuro-contextual advertising together.

We’re looking for a Backend Software Engineer to join our tech team and help build the future of neuro-contextual advertising at global scale. Who We Are At Seedtag, our mission is to transform advertising by proving that effectiveness and user privacy can truly coexist. As the leading Neuro-Contextual Advertising Company, we combine Artificial Intelligence, Natural Language Processing, Computer Vision, and neuroscience to understand not only what content is about, but how it makes people feel and what they intend to do next. Our proprietary AI, Liz, enables brands to connect with audiences across the open web and Connected TV without cookies or user tracking. Founded in 2014 by two ex-Googlers, Seedtag has grown to 700+ Seedtaggers in 17 countries, backed by €250M in funding, and operates today as a global ad-tech leader. If you enjoy solving complex engineering challenges and building AI-driven systems at scale, you’ll feel right at home here. Your Challenge As Backend Software Engineer, you will: - Be responsible for building and improving services which will have a direct impact on our client’s advertising KPIs and operational efficiency. - Work on end-to-end projects, taking solutions from concept to production, and focusing on creating scalable, efficient, and impactful solutions. - As a member of our engineering team, you will develop new projects mainly on the backend side, but sometimes, you’ll support particular frontend needs. You’ll be in charge of the CI/CD, dimensioning production instances and scaling. - Provide an analytical mindset, being able to go to our data lake in order to validate your own hypothesis and try to get your own conclusions to discuss afterwards with the team. - Collaborating closely with our cross-functional teams, your work will be aligned with business goals and drive the practical application of your solutions. Our Core Values Outcome over Output We measure success by impact and value, not by volume of features or lines of code. Failure Is Allowed, Learning Is a Must Experimentation is key to innovation. We test early, iterate often, and learn fast. We Are All Scouts We take ownership and leave things better than we found them. We Are Data-Driven Data informs our decisions and helps us continuously improve our systems and results. Tech Stack We operate at large scale, supporting up to 120k requests per second, with ML models responding in under 10 milliseconds and processing 20 TB of data daily. Our stack includes: - Languages: Python, Go, TypeScript, Scala - Cloud & Infrastructure: Kubernetes, GCP, AWS - Streaming: Kafka, Kinesis - Data: Datalakes, GCS, Redis, Druid, MongoDB - Architecture: 100+ microservices, DevOps-driven, continuous deployment What You’ll Need to Succeed - You bring 3-5 years of experience into backend software engineering, from the conceptualization of the problem to the deployment in production and validation that works. - You have collaborated on some front-end projects even if it’s not your strongest skill. - You are a DevOps-oriented engineer who is responsible for the CI/CD of the services you build, you understand how to do the sizing of production deployment and how to troubleshoot if something is not working as expected. - You deeply understand the problem you are trying to solve. You measure the outcome of the development you do. - You have worked in related disciplines which can include Data engineering pipelines, infrastructure provisioning or deployment of ML models in production. Why Join Seedtag? - A key moment of growth with real ownership and global impact. - Flexible work model with 100% remote or hybrid options. (Remote contracts available in Spain, Italy, UK, Belgium, Netherlands, France, and Germany.) - Continuous learning through a learning platform and optional language classes. - A supportive, trust-based culture that values well-being. - Team activities, offsites, and opportunities to connect beyond work. Additional Perks - Home office setup budget up to €1,000 - Paid trips to our HQ in Madrid - MacBook Pro M3 Ready to Join the Seedtag Adventure? At Seedtag, we create an environment where everyone can thrive. If you need accommodations during the hiring process, let us know and we’ll ensure a positive experience. Send us your CV and let’s build the future of neuro-contextual advertising together.

We’re looking for an Innovation Engineer to join our tech team and help build the future of neuro-contextual advertising at global scale. Who We Are At Seedtag, our mission is to transform advertising by proving that effectiveness and user privacy can truly coexist. As the leading Neuro-Contextual Advertising Company, we combine Artificial Intelligence, Natural Language Processing, Computer Vision, and neuroscience to understand not only what content is about, but how it makes people feel and what they intend to do next. Our proprietary AI, Liz, enables brands to connect with audiences across the open web and Connected TV without cookies or user tracking. Founded in 2014 by two ex-Googlers, Seedtag has grown to 700+ Seedtaggers in 17 countries, backed by €250M in funding, and operates today as a global ad-tech leader. If you enjoy solving complex engineering challenges and building AI-driven systems at scale, you’ll feel right at home here. The Role We are looking for an Innovation Engineer to join our Connected TV (CTV) squad within Seedtag. In this role, you will help build the next generation of smart TV advertising by exploring new technologies, prototyping innovative solutions, and delivering production-ready features. You will work in a fast-moving, startup-like environment within a global company, collaborating with developers and data scientists to improve audience understanding and ad targeting in a low-data CTV environment. This role combines technical expertise, creativity, and product thinking, giving you the opportunity to experiment with AI, large-scale data, and real-time systems while making a direct impact on the future of contextual advertising. Your Challenge - Research, prototype, and deploy innovative solutions to improve targeting and contextual understanding in CTV environments - Experiment with AI, LLMs, and emerging technologies to accelerate product innovation - Design and optimize workflows and pipelines to efficiently process large-scale datasets - Collaborate with developers, senior engineers, and data scientists to define user stories and product direction - Own solutions end-to-end, from idea and experimentation to production deployment - Contribute to system architecture, performance optimization, and monitoring - Explore new approaches to audience understanding and ad optimization in low-signal environments Our Core Values Outcome over Output We measure success by impact and value, not by volume of features or lines of code. Failure Is Allowed, Learning Is a Must Experimentation is key to innovation. We test early, iterate often, and learn fast. We Are All Scouts We take ownership and leave things better than we found them. We Are Data-Driven Data informs our decisions and helps us continuously improve our systems and results. Tech Stack We operate at large scale, supporting up to 120k requests per second, with ML models responding in under 10 milliseconds and processing 20 TB of data daily. Our stack includes: - Language: Python What You’ll Need to Succeed - Have a builder mindset and enjoy turning ideas into working prototypes and production-ready solutions - Are comfortable working autonomously and navigating ambiguity in a fast-paced environment - Bring strong software development skills (Python, Node.js/JavaScript, Go) and solid architectural understanding - Are curious about AI, machine learning, and emerging technologies, and enjoy experimenting with new tools - Have experience working with large-scale data workflows and high-throughput systems - Communicate effectively and collaborate well with cross-functional teams - Are product-oriented and motivated by delivering impactful, innovative solutions Nice to have: - Experience in contextual advertising or adtech - Familiarity with real-time streaming, microservices, or distributed systems - Hands-on experience with high-throughput data pipelines Why Join Seedtag? - A key moment of growth with real ownership and global impact. - Flexible work model with 100% remote or hybrid options. (Remote contracts available in Spain, Italy, UK, Belgium, Netherlands, France, and Germany.) - Continuous learning through a learning platform and optional language classes. - A supportive, trust-based culture that values well-being. - Team activities, offsites, and opportunities to connect beyond work. Additional Perks - Home office setup budget up to €1,000 - Paid trips to our HQ in Madrid - MacBook Pro M3 Ready to Join the Seedtag Adventure? At Seedtag, we create an environment where everyone can thrive. If you need accommodations during the hiring process, let us know and we’ll ensure a positive experience. Send us your CV and let’s build the future of neuro-contextual advertising together.

We’re looking for a Mid-Senior level Data Engineer to join our team and help shape the future of neuro-contextual advertising as we continue to expand globally. Who We Are At Seedtag, our mission is to transform advertising by proving that effectiveness and user privacy can truly coexist. As the leading Neuro-Contextual Advertising Company, we combine Artificial Intelligence, Natural Language Processing, Computer Vision, and neuroscience to understand not only what content is about, but how it makes people feel and what they intend to do next. Our proprietary AI, Liz, enables brands to connect with audiences across the open web and Connected TV without cookies or user tracking. Founded in 2014 by two ex-Googlers, Seedtag has grown to 700+ Seedtaggers in 17 countries, backed by €250M in funding, and operates today as a global ad-tech leader. If you enjoy solving complex engineering challenges and building AI-driven systems at scale, you’ll feel right at home here. Your Challenge As Data Engineer, you will: - Be a key player in the development of a reliable data architecture for ingestion, processing, and surfacing of data for large-scale applications. - Cooperate with other teams to unify data sources, as well as recommend and implement ways to improve data reliability, quality and integrity. - Work with data science and data analytics teams, to help them improve their processes by building new tools and implementing best practices. - Ensure continuous improvement in delivery, applying engineering best practices to development, monitoring, and data quality of the data pipelines. Our Core Values Outcome over Output We measure success by impact and value, not by volume of features or lines of code. Failure Is Allowed, Learning Is a Must Experimentation is key to innovation. We test early, iterate often, and learn fast. We Are All Scouts We take ownership and leave things better than we found them. We Are Data-Driven Data informs our decisions and helps us continuously improve our systems and results. Tech Stack We operate at large scale, supporting up to 120k requests per second, with ML models responding in under 10 milliseconds and processing 20 TB of data daily. Our stack includes: - Languages: Python, Go, TypeScript, Scala - Cloud & Infrastructure: Kubernetes, GCP, AWS - Streaming: Kafka, Kinesis - Data: Datalakes, GCS, Redis, Druid, MongoDB - Architecture: 100+ microservices, DevOps-driven, continuous deployment What You’ll Need to Succeed - You have at least 5 years of solid experience in Data Engineering. - You have a degree in Computer Science, Engineering, Statistics, Mathematics, Physics or another degree with a strong quantitative component.You are comfortable with object-oriented languages, such as Python or Scala, and you are fluent in working with a Linux terminal and writing basic bash scripts. - You have ample experience with Data Engineering tools such as BigQuery, Trino, Kafka or dbt. - You have experience orchestrating ETL processes using systems such as Apache Airflow, and managing SQL and NoSQL databases. - You are a team player and a proactive person who likes the dynamic scaleup work culture. Why Join Seedtag? - A key moment of growth with real ownership and global impact. - Flexible work model with 100% remote or hybrid options. (Remote contracts available in Spain, Italy, UK, Belgium, Netherlands, France, and Germany.) - Continuous learning through a learning platform and optional language classes. - A supportive, trust-based culture that values well-being. - Team activities, offsites, and opportunities to connect beyond work. Additional Perks - Home office setup budget up to €1,000 - Paid trips to our HQ in Madrid - MacBook Pro M3 Ready to Join the Seedtag Adventure? At Seedtag, we create an environment where everyone can thrive. If you need accommodations during the hiring process, let us know and we’ll ensure a positive experience. Send us your CV and let’s build the future of neuro-contextual advertising together.

We’re looking for a Senior Software Engineer - AI Agent Platform to join our tech team and help build the future of neuro-contextual advertising at global scale. Who We Are At Seedtag, our mission is to transform advertising by proving that effectiveness and user privacy can truly coexist. As the leading Neuro-Contextual Advertising Company, we combine Artificial Intelligence, Natural Language Processing, Computer Vision, and neuroscience to understand not only what content is about, but how it makes people feel and what they intend to do next. Our proprietary AI, Liz, enables brands to connect with audiences across the open web and Connected TV without cookies or user tracking. Founded in 2014 by two ex-Googlers, Seedtag has grown to 700+ Seedtaggers in 17 countries, backed by €250M in funding, and operates today as a global ad-tech leader. If you enjoy solving complex engineering challenges and building AI-driven systems at scale, you’ll feel right at home here. Your Challenge As Senior Software Engineer - AI Agent Platform, you will: - Design and build an enterprise-grade AI agent platform that handles real workloads, real users, and real constraints. - Own critical parts of the platform: agent orchestration, memory and context systems, tool integration layers, and external communication protocols. - Solve problems like managing conversation context at scale, coordinating multi-agent workflows, optimising LLM interactions, and exposing agent capabilities through standard protocols. - Make architectural decisions that balance performance, maintainability and developer experience. - Work closely with data scientists and product teams to ship agent capabilities that drive business outcomes. This space moves fast. Frameworks, protocols, and best practices evolve constantly. We build solid foundations but stay ready to adapt. You should be comfortable with change and eager to stay at the state of the art. Our Core Values Outcome over Output We measure success by impact and value, not by volume of features or lines of code. Failure Is Allowed, Learning Is a Must Experimentation is key to innovation. We test early, iterate often, and learn fast. We Are All Scouts We take ownership and leave things better than we found them. We Are Data-Driven Data informs our decisions and helps us continuously improve our systems and results. Tech Stack We operate at large scale, supporting up to 120k requests per second, with ML models responding in under 10 milliseconds and processing 20 TB of data daily. Our stack includes: - Languages: Python, Go, TypeScript, Scala - Cloud & Infrastructure: Kubernetes, GCP, AWS - Streaming: Kafka, Kinesis - Data: Datalakes, GCS, Redis, Druid, MongoDB - Architecture: 100+ microservices, DevOps-driven, continuous deployment What You’ll Need to Succeed - 5+ years building and operating backend systems in production, with strong distributed systems fundamentals. - Proficiency in Python and ideally Go. You care about code quality and maintainability. - Hands-on experience building LLM-based applications or AI agent systems using agent SDKs and frameworks (Pydantic AI, LangGraph, OpenAI Agents SDK, or similar). - Experience with Kubernetes, GCP or AWS, observability tools, CI/CD pipelines. - Understanding of agent patterns: tool calling, context management, and multi-step workflows. - Experience working with AI-assisted development tools. - Strong judgment and communication skills. You navigate ambiguity and make sound technical decisions. - Track record of owning projects end-to-end in fast-moving environments. Why Join Seedtag? - A key moment of growth with real ownership and global impact. - Flexible work model with 100% remote or hybrid options. (Remote contracts available in Spain, Italy, UK, Belgium, Netherlands, France, and Germany.) - Continuous learning through a learning platform and optional language classes. - A supportive, trust-based culture that values well-being. - Team activities, offsites, and opportunities to connect beyond work. Additional Perks - Home office setup budget up to €1,000 - Paid trips to our HQ in Madrid - MacBook Pro M3 Ready to Join the Seedtag Adventure? At Seedtag, we create an environment where everyone can thrive. If you need accommodations during the hiring process, let us know and we’ll ensure a positive experience. Send us your CV and let’s build the future of neuro-contextual advertising together.

We’re looking for a Mid-Senior Backend Engineer - AdExchange (Inventory & Enrichment) to join our tech team and help build the future of neuro-contextual advertising at global scale. Who We Are At Seedtag, our mission is to transform advertising by proving that effectiveness and user privacy can truly coexist. As the leading Neuro-Contextual Advertising Company, we combine Artificial Intelligence, Natural Language Processing, Computer Vision, and neuroscience to understand not only what content is about, but how it makes people feel and what they intend to do next. Our proprietary AI, Liz, enables brands to connect with audiences across the open web and Connected TV without cookies or user tracking. Founded in 2014 by two ex-Googlers, Seedtag has grown to 700+ Seedtaggers in 17 countries, backed by €250M in funding, and operates today as a global ad-tech leader. If you enjoy solving complex engineering challenges and building AI-driven systems at scale, you’ll feel right at home here. The Role You will join the AdExchange Engineering Team, the "engine room" of Seedtag. Your primary focus will be on Inventory Management and Bid Enrichment. This is a high-stakes environment where you will build the logic that categorises global ad inventory and enriches bidding requests with real-time contextual data. You will work in a high-throughput ecosystem where we don't just "deliver code"—we form hypotheses, measure real business impact, and iterate with an agile mindset to optimise our auction win rates and revenue. Your Challenge As a Mid-Senior Backend Engineer - AdExchange (Inventory & Enrichment), you will: - Inventory & Bid Enrichment: Own the core services that manage our global ad inventory and enrich bids with contextual metadata. This is a critical "hot path" in our infrastructure where low latency is non-negotiable. - High-Performance Node.js: Utilise Node.js, TypeScript, and Fastify to build ultra-low-latency services capable of handling hundreds of millions of requests daily. - Architectural Excellence: Lead the way in applying Hexagonal Architecture and Domain-Driven Design (DDD) to ensure our AdExchange remains maintainable and scalable as we grow. - Event-Driven Systems: Design and evolve our data pipelines using Kafka, ensuring that bid enrichment and inventory updates are processed reliably and asynchronously. - Technical Ownership: You will be responsible for making key technical decisions, managing project timelines, and collaborating with Data and Product teams to drive the project forward. - Quality & Observability: Ensure our services are not only fast but also resilient, well-tested, and fully observable through robust monitoring and logging practices. Our Core Values Outcome over Output We measure success by impact and value, not by volume of features or lines of code. Failure Is Allowed, Learning Is a Must Experimentation is key to innovation. We test early, iterate often, and learn fast. We Are All Scouts We take ownership and leave things better than we found them. We Are Data-Driven Data informs our decisions and helps us continuously improve our systems and results. Tech Stack We operate at large scale, supporting up to 120k requests per second, with ML models responding in under 10 milliseconds and processing 20 TB of data daily. Our stack includes: - Primary: Node.js, TypeScript, Fastify - Secondary: Go (Golang) - Data & Messaging: Kafka, MongoDB, Redis - Infrastructure: Kubernetes, AWS, Terraform - Patterns: DDD, Hexagonal Architecture, Event-Driven Microservices What You’ll Need to Succeed - The 5-Year Milestone: You have 5+ years of demonstrable experience in software engineering, with a focus on building high-performance backend systems. - Node.js & TypeScript Expert: You have a deep understanding of the Node.js event loop and asynchronous programming. Experience with Fastify is a significant plus. - Architectural Practitioner: You don't just know the theory; you have experience implementing Hexagonal Architecture (Ports & Adapters) and DDD. You know how to define clear domain boundaries and isolate business logic from infrastructure. - Distributed Systems Knowledge: You are comfortable with Event-Driven Architectures and message brokers like Kafka. You understand the challenges of eventual consistency and distributed data. - The "Big Picture" Thinker: You understand the business context of your work. You can balance the need for "perfect code" with the pragmatic need to deliver value and iterate based on data. - Software Craftsmanship: You are an advocate for Clean Code, SOLID principles, and TDD. You take pride in producing code that is easy for your peers to read and maintain. - Curiosity for Go: While our core stack for this role is Node.js, we have services in Go (Golang). You don't need to be an expert, but you should be excited to learn and contribute to our Go codebase when needed. - AI-Driven Efficiency: You see AI as a partner in engineering. You actively use AI tools to increase your productivity, from generating unit tests to refactoring legacy patterns. You are curious about how AI can help us build more resilient systems faster and you stay updated on the best ways to integrate it into a professional SDLC. Why Join Seedtag? - A key moment of growth with real ownership and global impact. - Flexible work model with 100% remote or hybrid options. (Remote contracts available in Spain, Italy, the UK, Belgium, the Netherlands, and Germany.) - Continuous learning through a learning platform and optional language classes. - A supportive, trust-based culture that values well-being. - Team activities, offsites, and opportunities to connect beyond work. Additional Perks - Home office setup budget up to €1,000 - Paid trips to our HQ in Madrid - MacBook Pro M3 Ready to Join the Seedtag Adventure? At Seedtag, we create an environment where everyone can thrive. If you need accommodations during the hiring process, let us know and we’ll ensure a positive experience. Send us your CV and let’s build the future of neuro-contextual advertising together.

We’re looking for a Fullstack Engineer - Ad Serving AdExchange to join our tech team and help build the future of neuro-contextual advertising at global scale. Who We Are At Seedtag, our mission is to transform advertising by proving that effectiveness and user privacy can truly coexist. As the leading Neuro-Contextual Advertising Company, we combine Artificial Intelligence, Natural Language Processing, Computer Vision, and neuroscience to understand not only what content is about, but how it makes people feel and what they intend to do next. Our proprietary AI, Liz, enables brands to connect with audiences across the open web and Connected TV without cookies or user tracking. Founded in 2014 by two ex-Googlers, Seedtag has grown to 700+ Seedtaggers in 17 countries, backed by €250M in funding, and operates today as a global ad-tech leader. If you enjoy solving complex engineering challenges and building AI-driven systems at scale, you’ll feel right at home here. Your Challenge As a Fullstack Engineer - Ad Serving AdExchange, you will: - High-Performance Ad Tags: Optimize our "Ad Tags" (Typescript) to ensure seamless rendering across millions of pages. You will deal with cross-browser compatibility, DOM manipulation, and the Critical Rendering Path where every millisecond counts. - SaaS & Design Systems: Lead the evolution of our Curation tools using a robust, scalable Design System to ensure a top-tier UX. - Fullstack Ownership: Work closely with backend engineers to contribute to the Node.js services. You will help design the APIs that feed our tags, ensuring they are as lean and fast as possible. - Scalable Architecture: Help us implement DDD (Domain-Driven Design) and Event-Driven patterns. We value your frontend expertise here to ensure our APIs are as developer-friendly as they are fast. Our Core Values Outcome over Output We measure success by impact and value, not by volume of features or lines of code. Failure Is Allowed, Learning Is a Must Experimentation is key to innovation. We test early, iterate often, and learn fast. We Are All Scouts We take ownership and leave things better than we found them. We Are Data-Driven Data informs our decisions and helps us continuously improve our systems and results. Tech Stack - Frontend: Typescript, React, Styled Components / Design Systems. - Client-Side: High-performance Vanilla JS/TS (Ad Tags). - Backend (Where you'll grow): Node.js, Go, Microservices. - Infrastructure: Kubernetes, Kafka, Redis. What You’ll Need to Succeed - Browser Internals Mastery: You have 5+ years of experience with TypeScript and deep knowledge of how browsers work (Event Loop, DOM, Web APIs, Security/Sandboxing). - The Ad Serving Mindset: You understand that "Frontend" in Adtech means building small, highly-optimized scripts that run on other people's websites without breaking them. - The Fullstack "Predisposition": You aren't just a UI developer. You have a strong interest in the backend (Node.js). You view the server as the natural extension of the client. - SaaS & Design Systems: You have experience building complex B2B platforms where consistency, reusability, and performance are paramount. - Software Craftsmanship: You advocate for Clean Code and SOLID principles. You believe that "done" includes being well-tested, documented, and observable. - Adaptability: You are excited by the idea of moving across the stack. You see the backend as an opportunity to broaden your impact rather than a chore. - Architecture Awareness: Even if your primary strength is in the client, you understand the principles of building scalable systems. You appreciate why we use Hexagonal Architecture or Clean Architecture to separate business logic from the delivery mechanism. You have a solid grasp in DDD and Event-Driven Architectures to design resilient APIs. - AI-Augmented Productivity: You embrace AI tools (GitHub Copilot, Claude code, LLMs, etc.) as a fundamental part of your daily workflow. You understand how to leverage these tools to speed up boilerplate coding, debugging, and learning, allowing you to focus on high-level architecture and complex problem-solving. Why Join Seedtag? - A key moment of growth with real ownership and global impact. - Flexible work model with 100% remote or hybrid options. (Remote contracts available in Spain, Italy, UK, Belgium, Netherlands, France, and Germany.) - Continuous learning through a learning platform and optional language classes. - A supportive, trust-based culture that values well-being. - Team activities, offsites, and opportunities to connect beyond work. Additional Perks - Home office setup budget up to €1,000 - Paid trips to our HQ in Madrid - MacBook Pro M3 Ready to Join the Seedtag Adventure? At Seedtag, we create an environment where everyone can thrive. If you need accommodations during the hiring process, let us know and we’ll ensure a positive experience. Send us your CV and let’s build the future of neuro-contextual advertising together.

We’re looking for a Data Scientist to join our tech team and help build the future of neuro-contextual advertising at global scale. Who We Are At Seedtag, our mission is to transform advertising by proving that effectiveness and user privacy can truly coexist. As the leading Neuro-Contextual Advertising Company, we combine Artificial Intelligence, Natural Language Processing, Computer Vision, and neuroscience to understand not only what content is about, but how it makes people feel and what they intend to do next. Our proprietary AI, Liz, enables brands to connect with audiences across the open web and Connected TV without cookies or user tracking. Founded in 2014 by two ex-Googlers, Seedtag has grown to 700+ Seedtaggers in 17 countries, backed by €250M in funding, and operates today as a global ad-tech leader. If you enjoy solving complex engineering challenges and building AI-driven systems at scale, you’ll feel right at home here. Your Challenge As Data Scientist, you will: - As a member of our data science team, you will build production-grade AI agent systems that interact with data, execute multi-step workflows, and make autonomous decisions impacting business outcomes. - You will design and implement agent architectures using modern frameworks, working on multi-agent orchestration patterns, agent delegation, and ensuring reliable execution under production constraints. - You will solve context management challenges across conversation history, tool outputs, and file attachments, implementing semantic search and retrieval systems to ensure agents have the right information to answer questions accurately. - You will integrate agents with data infrastructure, connecting them to databases and APIs in real-time, and implement tool integration systems that enable scalable development across teams using protocols like MCP. - You will build evaluation frameworks to measure agent performance in production, taking solutions from concept to deployment, and collaborating closely with cross-functional teams to align your work with business goals. Our Core Values Outcome over Output We measure success by impact and value, not by volume of features or lines of code. Failure Is Allowed, Learning Is a Must Experimentation is key to innovation. We test early, iterate often, and learn fast. We Are All Scouts We take ownership and leave things better than we found them. We Are Data-Driven Data informs our decisions and helps us continuously improve our systems and results. Tech Stack We operate at large scale, supporting up to 120k requests per second, with ML models responding in under 10 milliseconds and processing 20 TB of data daily. Our stack includes: - Languages: Python, Go, TypeScript, Scala - Cloud & Infrastructure: Kubernetes, GCP, AWS - Streaming: Kafka, Kinesis - Data: Datalakes, GCS, Redis, Druid, MongoDB - Architecture: 100+ microservices, DevOps-driven, continuous deployment What You’ll Need to Succeed - You bring 3-5 years of experience building and deploying production ML systems, with hands-on experience developing LLM-based applications or autonomous agents using frameworks like Pydantic AI, OpenAI Agents SDK, LangGraph, or similar, and the ability to adapt as the ecosystem evolves. - You possess strong software engineering skills with proficiency in Python and a track record of deploying services to production, including experience with async programming, API design, and production infrastructure like Docker and Kubernetes. - You have a strong academic background in fields such as Computer Science, Engineering, Statistics, Mathematics, or similar, with a focus on quantitative analysis and problem-solving, plus understanding of retrieval systems, embeddings, or context management patterns. - You have hands-on experience with end-to-end project workflows from design to deployment, understand multi-step agent workflows and tool calling patterns, and can handle the non-deterministic nature of LLM-based systems. - You are proactive, entrepreneurial, and adaptable, comfortable working in a fast-moving environment where best practices are still emerging, and committed to building reliable AI agent systems that drive measurable business outcomes. Why Join Seedtag? - A key moment of growth with real ownership and global impact. - Flexible work model with 100% remote or hybrid options. (Remote contracts available in Spain, Italy, UK, Belgium, Netherlands, France, and Germany.) - Continuous learning through a learning platform and optional language classes. - A supportive, trust-based culture that values well-being. - Team activities, offsites, and opportunities to connect beyond work. Additional Perks - Home office setup budget up to €1,000 - Paid trips to our HQ in Madrid - MacBook Pro M3 Ready to Join the Seedtag Adventure? At Seedtag, we create an environment where everyone can thrive. If you need accommodations during the hiring process, let us know and we’ll ensure a positive experience. Send us your CV and let’s build the future of neuro-contextual advertising together.

We’re looking for a Machine Learning Engineer to join our tech team and help build the future of neuro-contextual advertising at global scale. Who We Are At Seedtag, our mission is to transform advertising by proving that effectiveness and user privacy can truly coexist. As the leading Neuro-Contextual Advertising Company, we combine Artificial Intelligence, Natural Language Processing, Computer Vision, and neuroscience to understand not only what content is about, but how it makes people feel and what they intend to do next. Our proprietary AI, Liz, enables brands to connect with audiences across the open web and Connected TV without cookies or user tracking. Founded in 2014 by two ex-Googlers, Seedtag has grown to 700+ Seedtaggers in 17 countries, backed by €250M in funding, and operates today as a global ad-tech leader. If you enjoy solving complex engineering challenges and building AI-driven systems at scale, you’ll feel right at home here. Your Challenge - As a Machine Learning Engineer on Seedtag's Ad Exchange team, you will: - Build cutting-edge AI to optimise revenue flow while ensuring the needs of publishers and advertisers are met. - Research, design, test, deploy, and maintain AI models in a fully online environment to maximise margins, reduce operational costs, and enhance Seedtag's targeting capabilities. - Design and implement classical ML algorithms and control systems to ensure delivery of internal campaigns and maximise monetisation outcomes. - Build end-to-end data pipelines to train, validate, and analyse production model behaviour through custom dashboards. - Continuously improve our MLOps infrastructure, CI/CD pipelines, internal automations, and AI-supported workflows. - Collaborate closely with Data, Platform, and Backend Engineers to build services and infrastructure, from dataset generation to live model validation. Our Core Values Outcome over Output We measure success by impact and value, not by volume of features or lines of code. Failure Is Allowed, Learning Is a Must Experimentation is key to innovation. We test early, iterate often, and learn fast. We Are All Scouts We take ownership and leave things better than we found them. We Are Data-Driven Data informs our decisions and helps us continuously improve our systems and results. Tech Stack We operate at a large scale, supporting up to 120k requests per second, with ML models responding in under 10 milliseconds and processing 20 TB of data daily. Our stack includes: - Python & Go microservices - Kafka, Kinesis, Redis, GCS - Kubernetes on GCP & AWS - Druid, MongoDB, scalable data lake architecture - Typescript (Node.js) and Scala across other parts of the company What You’ll Need to Succeed - 3–6 years of experience building and deploying ML systems in production. - Strong Python skills and solid software engineering fundamentals (APIs, async programming, testing, clean architecture). - Experience working on both model development and production deployment. - Understanding of distributed systems, microservices, and cloud-native environments. - Familiarity with MLOps practices: model versioning, monitoring, CI/CD, reproducibility. - Experience with NLP, embeddings, and/or ranking models is a plus. - Comfortable debugging across layers: model behaviour, data issues, API performance, infrastructure bottlenecks. - Strong ownership mindset and ability to operate autonomously in fast-moving environments. Why Join Seedtag? - A key moment of growth with real ownership and global impact. - Flexible work model with 100% remote or hybrid options. (Remote contracts available in Spain, Italy, the UK, Belgium, the Netherlands, France, and Germany.) - Continuous learning through a learning platform and optional language classes. - A supportive, trust-based culture that values well-being. - Team activities, offsites, and opportunities to connect beyond work. Additional Perks - Home office setup budget up to €1,000 - Paid trips to our HQ in Madrid - MacBook Pro M3 Ready to Join the Seedtag Adventure? At Seedtag, we create an environment where everyone can thrive. If you need accommodations during the hiring process, let us know, and we’ll ensure a positive experience. Send us your CV and let’s build the future of neuro-contextual advertising together.

We’re looking for a Machine Learning Engineer to join our tech team and help build the future of neuro-contextual advertising at global scale. Who We Are At Seedtag, our mission is to transform advertising by proving that effectiveness and user privacy can truly coexist. As the leading Neuro-Contextual Advertising Company, we combine Artificial Intelligence, Natural Language Processing, Computer Vision, and neuroscience to understand not only what content is about, but how it makes people feel and what they intend to do next. Our proprietary AI, Liz, enables brands to connect with audiences across the open web and Connected TV without cookies or user tracking. Founded in 2014 by two ex-Googlers, Seedtag has grown to 700+ Seedtaggers in 17 countries, backed by €250M in funding, and operates today as a global ad-tech leader. If you enjoy solving complex engineering challenges and building AI-driven systems at scale, you’ll feel right at home here. Your Challenge As a Machine Learning Engineer on Seedtag's Ad Exchange team, you will: - Build cutting-edge AI to optimise revenue flow while ensuring the needs of publishers and advertisers are met. - Research, design, test, deploy, and maintain AI models in a fully online environment to maximise margins, reduce operational costs, and enhance Seedtag's targeting capabilities. - Design and implement classical ML algorithms and control systems to ensure delivery of internal campaigns and maximise monetisation outcomes. - Build end-to-end data pipelines to train, validate, and analyse production model behaviour through custom dashboards. - Continuously improve our MLOps infrastructure, CI/CD pipelines, internal automations, and AI-supported workflows. - Collaborate closely with Data, Platform, and Backend Engineers to build services and infrastructure, from dataset generation to live model validation. Our Core Values Outcome over Output We measure success by impact and value, not by volume of features or lines of code. Failure Is Allowed, Learning Is a Must Experimentation is key to innovation. We test early, iterate often, and learn fast. We Are All Scouts We take ownership and leave things better than we found them. We Are Data-Driven Data informs our decisions and helps us continuously improve our systems and results. Tech Stack We operate at a large scale, supporting up to 120k requests per second, with ML models responding in under 10 milliseconds and processing 20 TB of data daily. Our stack includes: - Python & Go microservices - Kafka, Kinesis, Redis, GCS - Kubernetes on GCP & AWS - Druid, MongoDB, scalable data lake architecture - Typescript (Node.js) and Scala across other parts of the company What You’ll Need to Succeed - 2–4 years of experience building and deploying ML systems in production. - Strong Python skills and solid software engineering fundamentals (APIs, async programming, testing, clean architecture). - Experience working on both model development and production deployment. - Understanding of distributed systems, microservices, and cloud-native environments. - Familiarity with MLOps practices: model versioning, monitoring, CI/CD, reproducibility. - Experience with NLP, embeddings, and/or ranking models is a plus. - Comfortable debugging across layers: model behaviour, data issues, API performance, infrastructure bottlenecks. - Strong ownership mindset and ability to operate autonomously in fast-moving environments. Why Join Seedtag? - A key moment of growth with real ownership and global impact. - Flexible work model with 100% remote or hybrid options. (Remote contracts available in Spain, Italy, the UK, Belgium, the Netherlands, and Germany.) - Continuous learning through a learning platform and optional language classes. - A supportive, trust-based culture that values well-being. - Team activities, offsites, and opportunities to connect beyond work. Additional Perks - Home office setup budget up to €1,000 - Paid trips to our HQ in Madrid - MacBook Pro M3 Ready to Join the Seedtag Adventure? At Seedtag, we create an environment where everyone can thrive. If you need accommodations during the hiring process, let us know and we’ll ensure a positive experience. Send us your CV and let’s build the future of neuro-contextual advertising together.