Staff ML Engineer — Post-Training & RL Pipelines

SF Tensor; San Francisco (CA); On-site; USD 275,000 - 315,000; Full time

Benefits offered by this job

Relocation assistance

Equity

Job summary

SF Tensor is building the fastest GPU compiler and model foundry to enable AI across clouds and chips. We’re hiring a Member of Technical Staff to own the modeling side from data curation through distillation to deployment, working with SFT, RL, and DPO to ship post-trained models in production.

This role sits in San Francisco, offers relocation assistance and meaningful equity, and pays a base salary of $275,000–$315,000 with comprehensive benefits.

Qualifications

• Shipped post-trained models into production.
• Hands-on depth across SFT and RL (DPO, GRPO, PPO or similar).
• Ability to judge evaluation: what to measure, what a result means and when a number is lying to you.
• Experience with data curation, labeling workflows and synthetic data generation.
• Proficient in PyTorch or JAX.

Responsibilities

• You'll own the post-training pipeline end-to-end: data curation, SFT, preference optimization, RL, evals, distillation and finally deployment
• You'll design reward functions and RL looks along customer domain experts, who know the task inside-out but not our training stack
• You'll build an eval harness trustworthy enough to make a ship/no-ship call within a short window, especially where the target is subjective taste rather than a scored benchmark
• You'll structure and generate datasets, including synthetic data pipelines, from whatever the customer actually has
• You'll distill specialist models down into smaller models
• You'll drive the time-to-model, which means finding what's actually on the critical path and removing it, run after run
• You'll embed with customers as a forward-deployed researcher, then hand the pipeline over cleanly when their team is ready to take over

Skills

Post-training models production

SFT

RL (DPO, GRPO, PPO)

PyTorch

JAX

Data curation

Forward deployment / customer-facing

Tools

GPU clusters

Job description

SF Tensor is building the fastest GPU compiler and model foundry to enable AI across clouds and chips. We’re hiring a Member of Technical Staff to own the modeling side from data curation through distillation to deployment, working with SFT, RL, and DPO to ship post-trained models in production.

This role sits in San Francisco, offers relocation assistance and meaningful equity, and pays a base salary of $275,000–$315,000 with comprehensive benefits.