Senior Software Engineer (RLE)

Handshake•San Francisco, CA

1d•Onsite

About The Position

We’re hiring a Senior Software Engineer to build our Reinforcement Learning Environments (RLE) platform—the interactive systems where frontier AI models learn to complete real-world work. RLE environments simulate workflows (e.g., software engineering, finance, legal) with realistic tools, constraints, and feedback loops. The data generated powers training and evaluation for model quality, robustness, and task completion. This is a high-ownership role with direct impact on how models learn and how quickly new domains scale.

Requirements

6+ years building backend, distributed systems, or ML infrastructure
Proficiency with ReactJS and TypeScript, with deep knowledge of backend architectures.
Strong command of relational databases (e.g., PostgreSQL), data modeling, system design, and distributed systems principles.
Experience with cloud infrastructure (AWS, GCP), CI/CD pipelines, and operating production systems at scale.

Nice To Haves

Experience with RL training infrastructure, simulation systems, or evaluation platforms
Working in an operations-heavy, tech-enabled environment
Experience supporting applied ML or AI research teams

Responsibilities

Build and scale our reinforcement learning environments and the platforms behind them
Drive architecture for scalable, reliable, extensible environment systems and data generation pipelines
Partner with Research, Product, and Ops to turn ambiguous needs into production systems
Build modular, plug-and-play domains that integrate cleanly with training and evaluation loops
Raise the bar on reliability, observability, performance, and data quality