Senior AI Research Engineer, Handshake AI

Handshake • San Francisco, CA

76d

About The Position

As a Senior Research Engineer, you'll play a leading role in designing and scaling the infrastructure, systems, and frameworks that power the next generation of LLM post-training and evaluation. You'll work closely with research scientists to define methodologies, push the boundaries of data quality and benchmark design, and mentor other engineers to raise the technical bar across the team. This role is ideal for someone who thrives at the intersection of research and large-scale engineering, with the ability to translate complex research insights into robust, production-grade systems.

Requirements

• Advanced proficiency in Python with a track record of building clean, maintainable, and performant codebases.
• 5+ years of experience in applied ML, large-scale distributed systems, or post-training infrastructure (RLHF, DPO, constitutional AI, etc.).
• Strong expertise with PyTorch and modern ML training frameworks; familiarity with distributed training and inference optimization.
• Proven experience designing and operating data pipelines, benchmark frameworks, or large-scale evaluation systems.
• Ability to drive technical projects end-to-end: from architecture design to implementation, scaling, and monitoring.
• Clear and confident communication skills; ability to collaborate across research and engineering disciplines and influence technical direction.

Nice To Haves

• Experience leading small teams or mentoring engineers.
• Track record of open-source contributions in ML infrastructure or evaluation frameworks.
• Publications or public talks in applied ML, evaluation, or systems research.
• Passion for building responsible AI systems and considering the societal/ethical implications of model evaluation.

Responsibilities

• Architect, implement, and optimize large-scale post-training systems and data processing pipelines, ensuring reliability, scalability, and performance.
• Lead the development of next-generation LLM benchmarks and evaluation frameworks, defining standards for measuring advanced reasoning, alignment, and knowledge capabilities.
• Design and enforce rigorous methodologies for verifying data integrity and quality across highly specialized datasets.
• Drive software/hardware performance optimization to accelerate experimentation and deployment (e.g., memory usage, training throughput, distributed systems).
• Partner with cross-disciplinary teams-including research scientists, domain experts, and product engineers-to validate and productionize model improvements.
• Mentor junior engineers and shape technical best practices for the post-training and evaluation engineering pod.
• Influence long-term research engineering strategy by identifying opportunities to systematize evaluation and data quality at scale.

Benefits

• Equity in a fast-growing company
• 401(k) match, competitive compensation, financial coaching
• Paid parental leave, fertility benefits, parental coaching
• Medical, dental, and vision, mental health support, $500 wellness stipend
• $2,000 learning stipend, ongoing development
• Stipends for home office setup, internet, commuting, and free lunch/gym in our SF office
• Flexible PTO, 15 holidays + 2 flex days, winter #ShakeBreak where our whole office closes for a week!
• Team outings & referral bonuses

What This Job Offers

• Job Type: Full-time
• Career Level: Senior
• Industry: Professional, Scientific, and Technical Services
• Number of Employees: 501-1,000 employees