Post-Training AI Systems Staff Engineer

Handshake; Mountain View (CA); Hybrid; USD 200,000 - 350,000; Full time

Benefits offered by this job

Ownership: Equity in a fast-growing US

Financial Wellness: 401(k) match, comp

Family Support: Parental leave, family

Wellbeing: Medical, dental, vision, $/

Growth: Learning stipend, development

Office: SF office access, commuting

Time Off: Flexible PTO, holidays

Connection: Team outings, referral

Compensation Range: $200K - $350K

Job summary

Handshake seeks a Member of Technical Staff, Post-Training to design and build post-training systems for frontier models. You will turn research questions into experiments, deliver production-grade data pipelines, and iterate rapidly with researchers and engineers.

You will shape evaluation frameworks, benchmarks, and reusable software while mentoring teammates and influencing technical direction in a fast-moving environment.

Qualifications

• 3+ years in post-training, fine-tuning, or model-evaluation work.
• Strong Python skills and ability to write clean, scalable software.
• Hands-on experience with ML tooling, especially PyTorch and large-scale data.
• Sound experimental judgment with meaningful metrics and failure diagnosis.
• Experience designing systems with tradeoffs on quality, scale, and reuse.
• Comfort operating in a fast-moving, ownership-driven environment.
• Collaborative, low-ego communication with researchers and engineers.

Responsibilities

• Design post-training systems and methodologies for frontier models.
• Translate research or partner needs into hypotheses and evaluation plans.
• Build and improve evaluation frameworks, benchmarks, and data pipelines.
• Run fast iteration loops: prototype, evaluate, interpret results, improve systems.
• Partner with AI researchers to develop high-signal data and methods.
• Identify patterns across engagements and build reusable software.
• Raise the technical bar with design judgment, code quality, and mentorship.
• Contribute to the field through benchmarks, tools, or open-source work.

Skills

Post-training work

Python

ML tooling

Experimental judgment

System design

Ambiguity navigation

Collaboration

Tools

PyTorch

Data pipelines

Jupyter

Job description

Handshake seeks a Member of Technical Staff, Post-Training to design and build post-training systems for frontier models. You will turn research questions into experiments, deliver production-grade data pipelines, and iterate rapidly with researchers and engineers.

You will shape evaluation frameworks, benchmarks, and reusable software while mentoring teammates and influencing technical direction in a fast-moving environment.