Research Engineer / Performance Engineer, RL Distributed Systems

United States Digital Space LLC; San Francisco (CA); Hybrid; USD 500,000 - 850,000; Full time

Job summary

United States Digital Space LLC in San Francisco is seeking an experienced software engineer to design, build, and operate RL-scale distributed systems. You will work across training, sampling, and environment execution on a large fleet, with a focus on reliability and performance.

You will collaborate with researchers and performance engineers to preserve training correctness, reduce tail latency, and implement observability, fault tolerance, and automation across the stack.

Qualifications

• Strong software engineering skills in Python and at least one systems language (Rust, C++, or Go).
• Experience designing, building, and operating large-scale distributed systems in production.
• Deep understanding of distributed systems fundamentals, including consistency, coordination, and failure modes.
• Ability to reason quantitatively about throughput, latency, and resource costs across compute, memory, storage, and network.
• Experience debugging complex failures across many hosts and services.
• Strong written communication, including design documents and incident writeups.

Responsibilities

• Design, build, and operate the distributed systems that run RL at scale, across training, sampling, and environment execution
• Find and remove whatever currently limits the system, whether it's scheduling, data movement, storage, networking, or coordination
• Build fault tolerance into every layer: failure detection, isolation, and recovery that keep long-running jobs making progress without human intervention
• Design resource management and autoscaling so that compute follows demand as a run's needs shift
• Build observability that makes it possible to understand what a run is doing and why it slowed down, stalled, or produced unexpected results
• Build automation that detects and remediates common problems, and design interfaces that let engineers and automated tools operate runs safely
• Work with researchers and performance engineers to make sure systems changes preserve training correctness and don't introduce subtle nondeterminism
• Remove classes of failure at their source through incident review, testing, and redesign, and write clear design documents for what you build

Skills

Python

Rust

C++

Go

Distributed systems

Performance analysis

Debugging

Technical writing

Tools

Kubernetes

Job description

About the company

the company’s mission is to create reliable, interpretable, and steerable AI systems. We want AI to be safe and beneficial for our users and for society as a whole. Our team is a quickly growing group of committed researchers, engineers, policy experts, and business leaders working together to build beneficial AI systems.

About the role

Reinforcement learning is how Claude learns to reason, write code, and act autonomously over long horizons. At frontier scale, an RL run is an unusually demanding distributed system. Training, sampling, and environment execution run concurrently across a large fleet of accelerators and hosts, exchange data continuously, and have to keep making progress while hardware fails, load shifts, and the research changes underneath them. How well that system holds together determines how much of our compute turns into learning, and how quickly the team can try the next idea.

Key responsibilities

• Design, build, and operate the distributed systems that run RL at scale, across training, sampling, and environment execution
• Find and remove whatever currently limits the system, whether it's scheduling, data movement, storage, networking, or coordination
• Build fault tolerance into every layer: failure detection, isolation, and recovery that keep long-running jobs making progress without human intervention
• Design resource management and autoscaling so that compute follows demand as a run's needs shift
• Build observability that makes it possible to understand what a run is doing and why it slowed down, stalled, or produced unexpected results
• Build automation that detects and remediates common problems, and design interfaces that let engineers and automated tools operate runs safely
• Work with researchers and performance engineers to make sure systems changes preserve training correctness and don't introduce subtle nondeterminism
• Remove classes of failure at their source through incident review, testing, and redesign, and write clear design documents for what you build

Minimum qualifications

• Strong software engineering skills in Python and at least one systems language such as Rust, C++, or Go
• Experience designing, building, and operating large-scale distributed systems in production
• Deep understanding of distributed systems fundamentals, including consistency, coordination, consensus, failure modes, and recovery
• Ability to reason quantitatively about throughput, latency, and resource costs across compute, memory, storage, and network
• Experience debugging complex failures across many hosts and services, including failures you can't reproduce locally
• Strong written communication, including design documents and incident writeups

Preferred qualifications

• Experience running ML training or inference infrastructure at scale
• Experience across several layers of the stack, such as scheduling, storage, networking, and orchestration
• Experience building schedulers, autoscalers, or resource management systems
• Experience with container orchestration such as Kubernetes, and with sandboxed or virtualized code execution at scale
• Experience with high-performance networking, RDMA, or collective communication libraries
• Experience building observability or automated remediation for large fleets
• Experience with async Python frameworks such as Trio or asyncio
• Familiarity with reinforcement learning or large language model training workloads

Representative projects

• Design a scheduler that places training, sampling, and environment work across a heterogeneous cluster while respecting network topology and failure domains
• Build a failure detection and recovery system that lets a long-running job survive host and network failures with minimal lost work
• Scale environment execution substantially without increasing tail latency for the training step
• Design an autoscaling policy that rebalances compute across components as a run's bottleneck shifts
• Build a diagnostics system that explains why a run's throughput dropped and proposes a fix
• Trace a rare data corruption bug across many services to a race condition in a recovery path, and redesign the path so the class of bug can't recur
• Design the operational interface for a run so that automated tools can safely diagnose and adjust it under human oversight

The annual compensation range for this role is listed below.

For sales roles, the range provided is the role’s On Target Earnings ("OTE") range, meaning that the range includes both the sales commissions/sales bonuses target and annual base salary for the role.

Annual Salary:

$500,000—$850,000 USD

LogisticsMinimum education: Bachelor’s degree or an equivalent combination of education, training, and/or experience

Required field of study: A field relevant to the role as demonstrated through coursework, training, or professional experience

Minimum years of experience: Years of experience required will correlate with the internal job level requirements for the position

Location-based hybrid policy: Currently, we expect all staff to be in one of our offices at least 25% of the time. However, some roles may require more time in our offices.

Visa sponsorship: We do sponsor visas! However, we aren't able to successfully sponsor visas for every role and every candidate. But if we make you an offer, we will make every reasonable effort to get you a visa, and we retain an immigration lawyer to help with this.

We encourage you to apply even if you do not believe you meet every single qualification. Not all strong candidates will meet every single qualification as listed. Research shows that people who identify as being from underrepresented groups are more prone to experiencing imposter syndrome and doubting the strength of their candidacy, so we urge you not to exclude yourself prematurely and to submit an application if you're interested in this work. We think AI systems like the ones we're building have enormous social and ethical implications. We think this makes representation even more important, and we