CareerPlan

Post-Training Applied Researcher

San FranciscoFull-time2026-10-07 → 2026-11-10
On-site

Core

Design and run post-training pipelines (SFT, GRPO, DPO, RLVR) to fine-tune open-source LLMs for specialized customer tasks using domain-specific datasets and reward engineering.

Role type

Applied Researcher (LLM Post-Training & RL)

Builds

Production-ready LLMs and training pipelines for customers in healthcare, code generation, and legal domains.

Domain

Artificial Intelligence / Large Language Models / Reinforcement Learning

Deliverable

production ML models

Required skills

LLM fine-tuning, Reinforcement Learning (GRPO, PPO), Reward Engineering, Multi-turn agent environment design, Synthetic data generation, Training pipeline orchestration, Experiment analysis (reward hacking, drift)

Preferred skills

RL training frameworks, Publications at NeurIPS/ICML/ICLR

Technologies

SFT, GRPO, DPO, RLVR, Python, PyTorch, Hugging Face (implied by open-source context)

Responsibilities

Design and run post-training pipelines including SFT, GRPO, DPO, RLVR, and reward function engineering. Build task-specific training environments and evals for customer domains. Work with customers to translate production data into training signal and design reward loops. Run and analyze training experiments to diagnose instabilities. Publish findings at top venues.

Seniority

Mid-Senior, hands-on IC