Full Stack Software Engineer, Agent Platform

Mercor•San Francisco, CA

1d•$130,000 - $500,000•Onsite

About The Position

Our agent platform is the core system Mercor uses to build, run, and showcase AI agents — the same platform our teams rely on internally every day and the one we demo live on customer calls. It is simultaneously our internal workbench and our external storefront. As a Full Stack Software Engineer on the Agent Platform team, you'll own these journeys end-to-end: the React frontend people interact with and the backend services that orchestrate agents, data, and integrations. You'll be directly responsible for the enablement of hundreds of internal users who depend on the platform daily, and dozens of enterprise clients who run on it in production. Because what you build is used in-house and demoed to customers, it has to be both genuinely powerful and demo-ready polished. This is a role for someone who cares equally about engineering craft and product impact: shipping scalable, reliable systems and intuitive interfaces that make everyone who touches the platform faster and more effective.

Requirements

2+ years of fullstack engineering experience building and shipping production software.
Deep proficiency in JavaScript/TypeScript (React + Next.js) and a strong grasp of frontend architecture, state management, and design patterns.
Solid backend experience in Python and/or Node.js — designing and building relational databases, REST APIs, and async task infrastructure.
Strong design sense and empathy for end-users; you hold a high bar for usability.
Experience with complex, high-throughput systems — pipelines, large data volumes, or multi-tenant architectures.
High ownership mindset; able to navigate ambiguity and drive projects from design through delivery.
Strong communication skills and ability to articulate technical and product tradeoffs clearly.

Nice To Haves

Experience building agent frameworks, LLM-powered products, or human-in-the-loop AI workflows.
Background in design systems, developer-facing APIs, or internal platform engineering.
Exposure to AI tools, real-time data, or data visualization.
Experience at top-tier tech companies or fast-scaling startups.

Responsibilities

Own the agent platform across the full stack — from the internal- and client-facing React interfaces to the backend APIs and services orchestrating agents, workflows, and integrations.
Enable hundreds of internal users and dozens of enterprise clients — ship the features, reliability, and polish that make the platform their daily driver and a confident live demo.
Build the foundational layer other teams depend on to stand up new agent use cases, task formats, and client configurations quickly and without rework.
Ship high-leverage product features that raise both internal productivity and the customer-facing quality of the platform.
Translate ambiguous requirements into well-scoped technical solutions through close collaboration with Applied AI researchers, product, design, and operations.