Software Engineer, Agents

About MercorMercor's mission is to organize human intelligence to power the AI economy. We're a leading AI data company, building the layer between human expertise and frontier models. Millions of domain experts on the platform are paid over $4 million per day to train frontier AI models. Mercor's APEX benchmark family measures AI's real-world impact on professional work. Mercor Enterprise brings this same infrastructure to Fortune 500 companies: helping companies capture how their best people actually work, translating that expertise directly back into agents. Mercor is creating a new category of work where expertise powers AI advancement. Achieving this requires an ambitious, fast-paced and deeply committed team. You’ll work alongside researchers, operators, and AI companies at the forefront of shaping the systems that are redefining society. Mercor is a profitable Series C company valued at $10 billion. We work in-person five days a week in our San Francisco, NYC, or London offices.About the RoleWe're looking for a strong engineer who can build agentic products that scale. You will work with:Backend: Python, FastAPI, Django, PydanticFrontend: Next.js, React, TypeScript, TailwindData: PostgreSQL, MySQL, Snowflake, DuckDB, RedisOrchestration/Infra: Kubernetes, Temporal, Modal, WozAgents/LLM: LangGraph, LangChain, FastMCP, Harbor, NemoGymObservability: Datadog, PostHog, LangSmithAt the end of the process, you’ll be team-matched to where you can have the most impact, on one of the following:Automation – We build intelligent systems and agents that automate operational work at scale—handling talent management, decision-making insights, and knowledge access—so humans can focus on higher-level thinking.This is a newly formed, CEO-facing team focused on 0→1 product development, with a strong emphasis on business impact. The work is highly cross-functional, touching nearly every system across the <company.Studio> – We own Mercor’s evaluation system & annotation platform for RL environments and tasks. We build harnesses, agents, verifiers, and the end-to-end infrastructure for producing frontier data. Our mission is to scale up high quality RL environments/tasks and expand their capabilities. We work closely with researchers at frontier AI labs to jointly shape the direction of next-generation models.What You’ll DoOwn agentic features end-to-end — from scoping with researchers/ops partners through implementation, launch, and iteration on real customer <feedback.Design> and ship LLM agents, harnesses, and verifiers — including the tools, prompts, and policies that make them <reliable.Build> the Python/FastAPI services and Temporal/Modal pipelines that orchestrate agent runs, human-in-the-loop review and <iterations.Build> state of the art RL environments that expand the capabilities of frontier agents, with realistic enterprise apps, simulated coworkers, and rich company data rooms that support tasks spanning hours to <days.Build> tooling that turns agent trajectories into insight, from statistical analysis to automated failure mode <detection.Build> and refine the full-stack surfaces and data infrastructure — craft Next.js/React interfaces where operators and experts work with agents, evolve data models to give agents the structured context and audit trails they need.Define agent quality and drive continuous improvement — build evals, instrument traces, analyze failure modes, and iterate on prompts, tools, and guardrails while raising the bar for reliability, cost, latency, and UX.Partner cross-functionally to shape agent autonomy — work with Product, Design, Research and Ops to draw the lines between autonomous action, propose-and-approve flows, and human-in-the-loop decisions.Why MercorImpact: Your work powers how the world’s leading AI labs train and test their models.Learning: Get early insights into frontier model capabilities months before the market.Growth: Work on both infrastructure and research-adjacent projects with fast paths to ownership.BenefitsBi-annual performance bonus structureGenerous equity grant vested over 4 yearsUp to $15k Relocation bonus$10K housing bonus (if you live within 0.5 miles of our office)$1.5K monthly stipend for mealsFree Equinox membership$200 monthly laundry reimbursement$200 monthly personal wellness reimbursementHealth, Dental, Vision insurance