# Member of Technical Staff, Data and RL at Sonder

- Company: Sonder
- What the company does: Backed by Greylock and a16z speedrun.
- Company website: https://www.sonder.com/
- Type: Startups (AI role)
- Level: Senior
- Location: New York City
- Work setup: On-site
- Pay: $250K to $300K base salary per year (USD)
- Posted: 2026-09-18
- Apply by: 2026-11-02
- Apply: https://jobs.ashbyhq.com/sonder/ca8bc957-e7ad-45bb-ab32-f4317bce20df
- Page: https://www.1752.vc/careers/jobs/sonder-member-of-technical-staff-data-and-rl/

## About the role

We are looking for a research engineer to improve model capabilities through better data, training environments, and reinforcement learning. You will work across data generation, environment design, and post-training, with ownership from an initial hypothesis to a measured improvement in model behavior. The work calls for strong engineering, careful experimentation, and judgment about what is worth pursuing.

## What they're looking for

- - Strong Python engineering skills and hands-on experience training or post-training language or multimodal models with PyTorch, JAX, or a comparable framework
- - Technical depth in reinforcement learning, synthetic data, or interactive environments, and the ability to work across the broader training pipeline
- - A practical understanding of policy optimization, reward design, and credit assignment in multi-step tasks
- - Evidence of rigorous experimental judgment: credible baselines, informative ablations, and clear explanations of what a result does and does not establish
- - Experience building dependable data or experiment infrastructure and debugging failures across the learning pipeline

Tags: Technical Staff