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Post-Training Applied Researcher

BasetenSan FranciscoEPD
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Salary
$200K – $275K
Job type
Full-time
Work mode
Remote
Experience
Senior
Posted
7 Oct 2026
Status
Open · checked 7d ago

About this role

San Francisco is the location for the Post-Training Applied Researcher position at Baseten, an opportunity suited for researchers with practical background in large language model fine-tuning and reinforcement learning. This position focuses on post-training open-source models to surpass proprietary options on specialized tasks.

Role Overview

This role centers on applied post-training research efforts, collaborating closely with high-growth artificial intelligence organizations. Responsibilities involve extracting utility from domain-specific datasets and developing reward functions, training pipelines, and evaluation harnesses. The resulting models deploy directly into production environments serving millions of users.

Key Responsibilities

Design and execute post-training workflows covering SFT, GRPO, DPO, RLVR, synthetic data generation, and reward function engineering.
Construct task-specific evaluation harnesses and training environments addressing domains such as legal, healthcare, and code generation, including multi-turn tool use and agentic workflows.
Collaborate directly with clients to convert production data into training signals, establishing reward loops and managing distribution shift.
Conduct and evaluate end-to-end training experiments, addressing issues like reward hacking, advantage estimation instabilities, and importance sampling drift.
Share research findings at top-tier venues and contribute to internal open-source training libraries.

Requirements

Practical experience training large language models utilizing reinforcement learning, showing deep comprehension of GRPO or PPO beyond basic reproduction.
Strong expertise in reward engineering, distinguishing between reliable training rewards and scalable exploits.
Background in developing multi-turn agent environments incorporating tool use beyond basic single-turn question-answering formats.
Capability to navigate the entire pipeline from dataset creation to training, evaluation, and eventual deployment.
Familiarity with production machine learning systems, with preference for closed training-inference loops.

Nice to Have

Familiarity with reinforcement learning training frameworks.
Research publications at venues such as NeurIPS, ICML, or ICLR concentrating on alignment, reward modeling, or reinforcement learning for large language models.

Skills and Tools

SFT
GRPO
DPO
RLVR
PPO
Python

Salary and Benefits

Salary range between $200,000 and $275,000 with equity offerings.
Full 100% medical, dental, and vision insurance coverage for U.S. employees and dependents.
Flexible paid time off and a company-wide winter break from Christmas Eve to New Year's Day.
Paid parental leave alongside a fertility and family-building stipend through Carrot.
Company-facilitated 401(k) plan for U.S. staff.

About the Company

Baseten supplies inference infrastructure for artificial intelligence companies, uniting applied research, developer tooling, and flexible infrastructure. The organization recently secured a Series F funding round led by Altimeter Capital, Conviction Partners, and Spark Capital.

How to Apply

Interested candidates should apply directly on the official Baseten careers page.

Skills and tech stack

SFTGRPODPORLVRPPOLLMLLMsSparkReinforcement LearningMachine LearningFine-tuning

Questions candidates ask

Where is the job located?

The position is located in San Francisco.

What is the salary range for this role?

The salary ranges from $200K to $275K alongside equity offerings.

What qualifications are required for the role?

Candidates need practical LLM training experience with reinforcement learning, strong reward engineering intuition, multi-turn agent environment building experience, full pipeline familiarity, and production ML systems background.

What benefits are provided to U.S. employees?

U.S. employees receive full medical, dental, and vision coverage, a company-facilitated 401(k), flexible PTO, parental leave, and a Carrot family-building stipend.

Ready to apply?

The application is on the official Baseten careers page.

Apply on company site