ABOUT THE ROLE
Frontier labs train and evaluate their models inside environments Mercor builds: sandboxed codebases, enterprise applications, multi-tool agent worlds, and the verifiers that score what an agent did. The Environments Infrastructure team owns the platform that builds those environments, runs them at scale, and gets them to the customer, however a given customer wants to consume them, from a service they call directly to a dataset they run in their own stack.
That makes this team the layer between everything Mercor authors and everyone who runs it. We build the core environment runtime, the structure of the environments themselves, the services that other teams at Mercor build on, the integrations our lab customers build against, and the pipelines that carry an environment from authoring to a training run. Every environment Mercor ships goes through this stack.
The team is small, the surface area is large, and most of the big design questions are still open. You will own real pieces of this platform end to end and see what you build in use at the biggest AI labs within weeks of shipping.
WHAT YOU WILL DO
Own the pipelines that take an environment from authoring to a lab's hands, including the packaging, validation, and versioning that make a delivery trustworthy.
Design, build, and operate the core environment runtime: how environments are built, isolated, launched, and torn down across tens of thousands of concurrent sandboxes.
Build the services other teams at Mercor use to run environments, and the APIs and integrations our lab customers build against.
Build and extend the harnesses that run agents inside our environments, and keep results consistent between our stack and a lab's.
Own features end to end: scope the problem, write the design, ship it, instrument it, and keep it healthy in production.
Work on modern cutting edge tools, libraries and frameworks.
Build for scale and reliability in the pipelines and job systems that move work through the platform: queuing, batching, retries, backpressure, and recovery when things break.
Participate in on-call for the systems you own and write up what you learn in RCCA.
Work directly with product, operations, and research partners to turn ambiguous requirements into systems that ship.
WHAT WE ARE LOOKING FOR
3+ years building and operating production backend or infrastructure systems.
Strong fundamentals: data structures, concurrency, distributed systems, and quality code contributions.
Hands-on API design, with an understanding of versioning and backward compatibility.
Solid relational database skills: data modeling, query performance, and safe migrations.
Deep comfort with containers and Linux: image builds, isolation, networking, and debugging at scale.
Experience running workloads on Kubernetes or a serverless container platform like Modal.
Experience running services in production: containers, CI/CD, monitoring and alerting, and debugging issues under real traffic.
Clear written and verbal communication. High ownership, pragmatism, and a bias toward shipping.
NICE TO HAVE
Experience with agent harnesses, RL environments, or evaluation infrastructure.
Experience with workflow orchestration systems like Temporal, Airflow, or Dagster.
Experience building or integrating with LLM-backed services in production (evaluation, orchestration, or serving).
Familiarity with sandboxing and microVM runtimes such as gVisor, Firecracker, or Kata.
Terraform or other infrastructure as code, and production experience on more than one cloud.
Benefits
Generous equity grant vested over 4 years
Health, dental, and vision insurance
401(k) with company match
Unlimited paid vacation and sick days
Parental leave for birthing and non-birthing parents
Free mental health services
$200 monthly wellness reimbursement
$1.5K monthly meal stipend
$200 monthly laundry reimbursement
Free Equinox membership
Up to $15K relocation bonus
Mercor is an Equal Opportunity Employer and is committed to providing equal opportunity to all employees and applicants. Mercor does not discriminate based on actual or perceived race, color, creed, religion, national origin, ancestry, citizenship status, age, sex or gender (including pregnancy, childbirth, related medical conditions and lactation), gender identity or gender expression, sexual orientation, marital status, military service and veteran status, disability, protected medical condition as defined by California or local law, genetic information, or any other characteristic protected by applicable federal, California, or local laws and ordinances. Further, Mercor prohibits discrimination, harassment, and retaliation based on any combination of protected characteristics. This Policy applies to all areas of employment, including recruitment, hiring, training, promotion, compensation, benefits, discipline, termination, and all other privileges, terms, and conditions of employment. This Policy and the law prohibit employment discrimination against any employee or applicant based on any legally protected status.
