Member of Technical Staff, Post-Training

The role

You will design post-training systems and methodologies for frontier models. You will partner with researchers and domain experts to turn research needs into experiments, evaluation frameworks, and data pipelines.

What you will do

• Design post-training systems and methodologies for frontier models.
• Translate research or partner needs into hypotheses, experiments, and implementations.
• Build and improve evaluation frameworks, benchmarks, and data-processing pipelines.
• Run fast, rigorous iteration loops to prototype and evaluate results.
• Partner with AI researchers and domain experts to develop data and evaluation methods.
• Identify repeatable patterns and productize them into reusable software and platforms.
• Raise the technical bar through design judgment, communication, and mentorship.
• Contribute to the field through benchmarks, open-source tools, research, and technical writing.

Required qualifications

• 3+ years of demonstrated strength in post-training, fine-tuning, or model-evaluation work.
• Strong Python skills.
• Ability to write clean, efficient, scalable software.
• Hands-on experience with modern ML tooling, particularly PyTorch and large-scale data, training, or evaluation workflows.
• Sound experimental judgment.
• Experience designing systems including making tradeoffs around quality, scale, reliability, and reuse.
• Comfort operating in an ambiguous, fast-moving environment with substantial ownership.
• Collaborative, low-ego communication.

Nice to have

• Building or operating large-scale ML training, inference, data, or evaluation systems.
• Developing LLM/agent benchmarks, evaluation methodologies, annotation systems, or data-quality frameworks.
• Research or applied work on reinforcement learning, alignment, model behavior, synthetic data, or human-in-the-loop systems.
• Published research, meaningful open-source contributions, or evidence of technical leadership in ML systems or AI research.
• Experience productizing research or repeated customer work into robust, reusable platforms.

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
• Commuting support, free lunch, and gym in our SF office

About the company

Handshake's mission is to organize expert human knowledge to advance the AI economy. Handshake AI works with frontier labs on data, evaluation, and post-training challenges.