Role Description As a Senior Backend Engineer on our Detection team, you will develop, support, and maintain the core hCaptcha application tools and services that detect and verify user events. You will work closely with Security and Machine Learning engineers to continuously build features that improve hCaptcha's capabilities by leveraging languages such as JavaScript and or Go to solve problems that impact users on a global scale. You will practice DevSecOps, handling operations around your code including security implementations, monitoring, automation, and production systems. Our customer-focused organization means you will interact directly with enterprise customers and startups when needed, alongside our product, customer success, and sales teams. Using AI: Coding agents are indisputably useful tools. We provide access to the top 3 models, and were early adopters of evals-first development flows. Familiarity with coding using agents is part of all interviews. However, reliability and correctness are critical for us. You will need to read and understand every line of code with your name on it, and it will be reviewed by both people and machines. What will you do: - Collaborate with team members and domain experts to execute on solutions that directly impact the ability to detect and mitigate fraud and automation. - Design and implement features that aim for low-latency, high-availability, transparent performance insights. - Write clearly structured, maintainable, well-documented, and tested code that meets open-source quality standards. - Support engineering excellence through code reviews, test automation, and on-call participation. What you will learn: - Experience working with systems that serve hundreds of millions of daily users. - Security and Machine Learning expertise through product development and company knowledge sharing. - Cutting-edge technology to be leveraged in solutions to combat the ever evolving cybersecurity landscape. Qualifications - 4+ years of hands-on experience in backend engineering roles. - Proven experience building scalable solutions with JavaScript and/or Go. - Expertise in Web APIs, HTTP, SSL, and database management. - Strong background with serverless and containerization architectures. - Proficiency in network protocols and distributed systems. Requirements - Production experience with Python and Rust or Go. - Knowledge of security frameworks (OWASP, CISA), attack vectors, botnets, etc. - Experience working across infrastructure such as developing CI/CD pipelines, metrics-driven deployments, managing system resources, etc. Benefits - Fully remote position with flexible working hours. - An inspiring team of colleagues spread all over the world. - Pleasant, modern development and deployment workflows: ship early, ship often. - High impact: lots of users, happy customers, high growth, and cutting edge R&D. - Flat organization, direct interaction with customer teams. We celebrate equality of opportunity and are committed to creating an inclusive environment for all team members. Join us as we transform cybersecurity, user privacy, and machine learning online! Please note that all positions require pre-employment screening, including third-party verification of work history, education, and identity, as well as a final in-person interview and identity verification step, which will be conducted in your country of residence.