Block builds simple, powerful tools that make progress towards an economy that’s truly open to all. Each of our brands unlocks different aspects of the economy for more people. Square makes commerce and financial services accessible to sellers. Cash App is the easy way to spend, send, and store money. Afterpay is transforming the way customers manage their spending over time. TIDAL is a music platform that empowers artists to thrive as entrepreneurs. Bitkey is a simple self-custody wallet built for bitcoin. Proto is a suite of bitcoin mining products and services. Together, we’re helping build a financial system that is open to everyone. Join us. The Role Traditionally, ML systems were built to solve narrow tasks (e.g., item recommendations), with orchestration logic hard-coded outside the model. Increasingly, LLMs are becoming the orchestration layer, deciding which models to invoke, when to use them, how to interpret outputs, and how to chain steps together. In this paradigm, the models we build deliver low-latency, large-scale personalization that advances Block’s mission of economic empowerment. We work closely with Design, Product, and Engineering teams across Block’s ecosystem, applying a spectrum of approaches from simple heuristics and embeddings to deep learning and large language models. We also invest heavily in agentic engineering and AI-assisted tooling to enable high-velocity, reliable development. This includes code generation, automated testing, documentation, and developer workflows. You will play a key role in shaping how these practices scale, ensuring they remain rigorous, auditable, and trusted as their impact grows. You Will - Lead strategic initiatives in AI Personalization, driving the vision, architecture, and execution - Develop and deploy new AI/ML models that power search & recommendations in traditional UX as well as new agentic interfaces - Deploy to production at scale to personalize every user’s experience - Be a technical leader and establish quality practices that stick, make broader design decisions and set an example for others to follow - Collaborate with a cross functional team of designers, business partners, and software engineers to build new technologies and features - Design experiments, test them on production users, analyze and repeat You Have - 10+ years building and operating quality software - Domain expertise in recommender systems, ranking systems, or similar with 5+ years of experience - Led the development of complex models trained on large datasets powering customer facing features - Strong software engineering skills - Strong communication skills and customer empathy - Experience with PyTorch, PySpark, Databricks and AWS is a plus Technologies We Use and Teach - We work with a modern, production-grade stack that includes industry-standard tools such as PyTorch, PySpark, Prefect, and Databricks - Alongside these, a core part of the role is evaluating and prototyping with a rapidly evolving set of internal platforms and tooling - Block is investing heavily in AI, and our modeling workflows are evolving accordingly - This creates a rare opportunity to work with emerging systems as they take shape—both leveraging them in practice and influencing how they are designed - The team is at the forefront of rethinking how models are built, validated, and deployed in an AI-first environment, with the goal of setting new industry standards We're working to build a more inclusive economy where our customers have equal access to opportunity, and we strive to live by these same values in building our workplace. Block is an equal opportunity employer evaluating all employees and job applicants without regard to identity or any legally protected class. We will consider qualified applicants with arrest or conviction records for employment in accordance with state and local laws and "fair chance" ordinances. We believe in being fair, and are committed to an inclusive interview experience, including providing reasonable accommodations to disabled applicants throughout the recruitment process. We encourage applicants to share any needed accommodations with their recruiter, who will treat these requests as confidentially as possible. Want to learn more about what we're doing to build a workplace that is fair and square? Check out our I+D page. While there is no specific deadline to apply for this role, U.S. roles are typically open for an average of 55 days before being filled by a successful candidate. Please refer to the date listed at the top of this job page for when this role was first posted. Block takes a market-based approach to pay, and pay may vary depending on your location. U.S. locations are categorized into one of four zones based on a cost of labor index for that geographic area. The successful candidate’s starting pay will be determined based on job-related skills, experience, qualifications, work location, and market conditions. These ranges may be modified in the future. To find a location’s zone designation, please refer to this resource. If a location of interest is not listed, please speak with a recruiter for additional information. Zone A: $228,700—$343,100 USD Zone B: $217,300—$325,900 USD Zone C: $205,900—$308,900 USD Zone D: $194,500—$291,700 USD Application Guidelines Candidates may submit up to 9 active applications within a 60-day period. Reapplications to the same role are accepted 90 days after a previous application has been reviewed. Use of AI in Our Hiring Process We may use automated AI tools to evaluate job applications for efficiency and consistency. These tools comply with local regulations, including bias audits, and we handle all personal data in accordance with state and local privacy laws. Contact us here with hiring practice or data usage questions. Every benefit we offer is designed with one goal: empowering you to do the best work of your career while building the life you want. Remote work, medical insurance, flexible time off, retirement savings plans, and modern family planning are just some of our offering. Check out our other benefits at Block. Block, Inc. (NYSE: XYZ) builds technology to increase access to the global economy. Each of our brands unlocks different aspects of the economy for more people. Square makes commerce and financial services accessible to sellers. Cash App is the easy way to spend, send, and store money. Afterpay is transforming the way customers manage their spending over time. TIDAL is a music platform that empowers artists to thrive as entrepreneurs. Bitkey is a simple self-custody wallet built for bitcoin. Proto is a suite of bitcoin mining products and services. Together, we’re helping build a financial system that is open to everyone. Privacy Policy

Role Description We are looking for a Machine Learning Scientist with specific background and skills in the LLM space, who is passionate about applying AI and ML to solve high-impact societal challenges. The ideal candidate will have a strong research background with 3+ years of relevant LLM experience or a PhD in the LLM area, and expertise in designing and implementing machine learning models, data analysis, and simulations. - Expertise beyond building RAG systems and prompt engineering. - Skilled in mentoring junior researchers and working in cross-functional teams. - Contributing to both practical deployments and academic research. - Demonstrated commitment to social good. - Strong communication skills and ability to translate complex problems into deployable ML solutions. As an ML Scientist, you will be responsible for building machine learning solutions to problems of societal importance and mentoring other team members in this effort. You will participate in stakeholder engagements, setting critical requirements, problem definition, and the development and execution of algorithms and solutions to the problems. - Understand user challenges and their context. - Curate and transform data. - Train and validate models. - Create evaluations and benchmarks. - Run simulations and derive insights from data. - Work in cross-functional teams spanning engineering, solutions, domain experts, and designers. - Collaborate with social sector organisations and researchers across the world. You will be encouraged to drive fundamental advances to the technology domains themselves as part of the efforts towards their application, present your work in technical and other forums of interest, and publish in leading conferences and journals. - Excellence as an individual contributor goes together with good teamwork and collaboration. - Mentor junior researchers, post-docs, and interns. - Participate in recruiting and hiring activities. - Interact with external partners when required. - Make periodic visits to the communities from where challenges are derived and where the solutions will be deployed. Qualifications - Bachelor’s degree or equivalent in Computer Science, Electrical Engineering, Statistics, Applied Mathematics, Physics, Economics or a relevant quantitative field with relevant work experience of 6+ years OR a Master’s degree in these fields with 4+ years of relevant experience OR a Ph.D. in Machine Learning with a focus on LLMs from a reputed institute. - Experience applying AI, machine learning, and data science to real-world problems. - Strong research background. - Experience in mentoring junior researchers through strong code practices and ideation. - Adept at a variety of data mining/analysis methods and tools. - Building and implementing models, visualising data, creating/using algorithms, and running simulations. - Familiarity with popular deep learning algorithms, transformer architectures, and advances in LLMs or foundation models. - Experience with building and evaluating conversational (multi-turn) chatbots is a plus. - Comfortable working with cross-functional teams. - Excellent oral and written communication skills. - Track record of driving projects to completion. - Evidence of written skills through high quality research publications is a plus. - Passionate about using technical skills to solve large societally important problems. Benefits - Insurance Benefits - Medical Insurance, OPD Coverage, Accidental Insurance, Life Insurance. - Wellness Program - Employee Assistance Program, Annual Health Check-Ups, Onsite Medical Centers, Emergency Support System. - Parental Support - Maternity Benefit, Travel Reimbursement for Expectant Mothers during Last Trimester, Paternity Benefit, Day Care Support Program. - Mobility Benefits - Travel Policy, Relocation and Deputation benefits. - Statutory Benefits - Employee PF Contribution, Gratuity, Leave Encashment. - Other Benefits – Unlimited Leave Policy, Professional Development Policy, Referral Bonuses, Internet and Telephone Allowance. We care deeply about the well-being of our employees and their families. You will get an opportunity to take on roles beyond a defined job description. Take a look at our website www.wadhwaniai.org to learn more about our work on AI for Social Impact. These are just some of the reasons why working with us is more than just a job — it's a chance to grow, thrive and contribute to society.

Role Description Parsons is looking for an amazingly talented AI/ML Engineer to join our team! What You'll Be Doing: - Design, develop, and deploy AI/ML models and tools for data mining, predictive modeling, and knowledge discovery to enhance chemical and biological threat characterization. - Build and optimize automated data pipelines for semantic/contextual chunking, named entity extraction, vector embedding, and relationship extraction. - Integrate AI/ML-enabled capabilities into a secure, cloud-based data architecture, ensuring interoperability with existing systems via standardized APIs and the Model Context Protocol (MCP). - Develop and maintain model cards documenting model purpose, training data, performance metrics, limitations, and ethical considerations. - Implement and monitor model performance, data/concept drift, and key metrics in real time; support model retraining and fine-tuning as new data becomes available. - Collaborate with data engineers, software developers, and stakeholders to define requirements, validate outputs, and support the creation of knowledge graphs and enriched data products. - Ensure all AI/ML workflows comply with DoD cybersecurity, data privacy, and access control requirements, including operation within isolated cloud environments. - Develop tools and dashboards for model explainability, transparency, and user interaction with AI/ML outputs. - Participate in Agile sprints, contribute to backlog refinement, and support documentation for AI/ML components. - Assist in knowledge transfer and training activities, including the development of tutorials and best practices for AI/ML usage. Qualifications - Active Secret or higher security clearance. - Bachelor’s degree in Computer Science, Data Science, Machine Learning, or a related technical field. - 3-8 years of experience developing and deploying AI/ML models in production or enterprise environments. - Proficiency with AI/ML frameworks and libraries (e.g., LangChain, LlamaIndex, TensorFlow, PyTorch). - Experience building and maintaining data pipelines for machine learning, including data preprocessing, feature engineering, and model deployment. - Strong programming skills in Python or similar languages. - Experience with cloud platforms (e.g., AWS, Azure) and cloud-native AI/ML services. - Familiarity with RESTful APIs and integrating AI/ML models into larger software systems. - Understanding of data security, privacy, and access control best practices. - Experience working in Agile development environments and collaborating with multidisciplinary teams. - Strong analytical, problem-solving, and communication skills. Requirements - Master’s degree in Data Science, Machine Learning, or a related field. - Experience with large language models (LLMs), vector/semantic search, and advanced NLP techniques. - Familiarity with DoD cybersecurity and data governance standards (e.g., NIST SP 800-171, STIG, RMF). - Experience developing AI/ML solutions for knowledge graph construction and ontology-based reasoning. - Experience with model explainability, bias detection, and ethical AI practices. - Experience with containerization (Docker, Kubernetes) and secure model deployment. - Experience integrating AI/ML solutions in classified environments (e.g., SIPR, JWICS). - Prior experience supporting government or defense-related AI/ML projects. Benefits - Medical, dental, and vision insurance. - Paid time off. - 401(k) plan. - Life insurance. - Flexible work schedules. - Holidays to fit your busy lifestyle.

Role Description Work on exciting and diverse projects in a wide range of fields including data intelligence, voice recognition, medicine, genomics, speech, and other applications. We develop tools spanning data science, big data, and machine learning domains for government and commercial customers. - ML and statistical model development and analysis for predictive maintenance - Data science and algorithm development for predicting mental health status - High throughput ML analysis of protein structure and shape using cloud resources - Development of conversational AI agents based on large language models (LLMs) Duties/Responsibilities: - Design, develop, and enhance engineering solutions for challenging problems. - Implement, test, perform analysis, and provide documentation support. - Generate and present test reports including plots, tables, evaluation criteria, and conclusions from data collected and analyzed throughout the test process. - Complete assignments designed to develop a practical knowledge of processes, procedures, equipment, facilities, and systems as well as their interrelationships within engineering disciplines. - Perform other duties as assigned. Qualifications - Intern: Position is full time and can be remote or in Cambridge, MA. - Classes and projects involving machine learning, algorithm development, data analytics, computer vision, or computational modeling. - B.S. (in progress) in computer science, machine learning, statistics, electrical engineering, computational biology, physics, or related field. - Creative individual, team player, self-starter. - Scientific thinking and the ability to invent, demonstration of thought leadership. - Solid programming experience (e.g., Python, Matlab, Java). - Applicants selected for this position may be required to obtain and maintain a government security clearance. Requirements - Enrolled in an accredited full-time undergraduate or graduate degree program required. - There is flexibility regarding hours and program duration based on applicant’s school schedule and availability. Benefits - Workplace flexibility. - Employee clubs ranging from photography to yoga. - Health and finance workshops. - Off-site social events. - Discounts to local museums and cultural activities. Company Description Draper is an independent, nonprofit research and development company headquartered in Cambridge, MA. The 2,000+ employees of Draper tackle important national challenges with a promise of delivering successful and usable solutions. From military defense and space exploration to biomedical engineering, lives often depend on the solutions we provide. Our multidisciplinary teams of engineers and scientists work in a collaborative environment that inspires the cross-fertilization of ideas necessary for true innovation.