Mercor
Software Engineer, Agents
About this role
Mercor seeks a full-stack engineer to build scalable agentic products that automate enterprise work or power AI evaluation infrastructure. You'll own features end-to-end across Python backends, React frontends, LLM orchestration, and RL environments, working with frontier AI labs and internal teams.
What you'll do
- Own agentic features from design through launch, including LLM agents, tools, and verifiers
- Build Python/FastAPI services and Temporal/Modal pipelines for orchestrating agent runs and human-in-the-loop workflows
- Create RL environments and harnesses that test frontier agent capabilities on realistic enterprise tasks
- Develop Next.js/React interfaces for operators to interact with and evaluate agents
- Define agent quality metrics, build evals, and drive continuous improvement through trace analysis and prompt iteration
- Partner cross-functionally to shape autonomy levels and decision-making flows between agents and humans
What they're looking for
- Python, FastAPI, Django, Pydantic
- Next.js, React, TypeScript, Tailwind
- PostgreSQL, MySQL, Snowflake, DuckDB, Redis
- Kubernetes, Temporal, Modal orchestration
- LangGraph, LangChain, LLM frameworks
- Agent design and prompt engineering
- Datadog, PostHog, observability tools
- Full-stack system design at scale
Benefits
- Bi-annual performance bonus structure
- Generous equity grant vested over 4 years
- Up to $15k relocation bonus
- $10k housing bonus (within 0.5 miles of office)
- $1.5k monthly meals stipend
- In-person 5 days/week in NYC, San Francisco, or London
Opens the application — the Jobs AI extension fills it for you. Set up autofill
Opens the official application on the employer’s site. No login required.
Mercor
Mercor builds a marketplace platform connecting expert talent to AI opportunities, supported by identity infrastructure, matching algorithms, and internal tools for data management. The company is hiring Software Engineers, Machine Learning Engineers, Fullstack Engineers, and Security Engineers to develop backend systems, ML models, cloud infrastructure, and distributed platforms.
- Website
- mercor.io
Likely interview questions
- Walk us through how you'd design an agentic system that handles multi-hour enterprise workflows with human-in-the-loop checkpoints—what patterns would you use for state management and rollback?
- Describe your experience building or working with LLM agents. How do you approach prompt engineering and tool design to make agents reliable and cost-effective?