Senior Software Engineer

The role

You will own features end to end across a Next.js, React, and TypeScript application. You will build LLM-powered member experiences and design evaluation and observability for AI features.

What you will do

• Own features end to end across Next.js/React/TypeScript app, Prisma/Postgres backend, and AWS infrastructure
• Extend AI coach and build new LLM-powered member experiences
• Design evaluation and observability for AI features
• Push AI-assisted development practice forward
• Handle sensitive health data responsibly
• Review code written by humans or agents
• Mentor teammates and raise the bar on testing and reliability

Required qualifications

• 5+ years building production web applications
• Deep TypeScript, React, and Node experience
• Comfort with relational data modeling using Prisma and Postgres
• Experience with auth flows, caching, background jobs, and cloud deployment (AWS, Docker, Terraform or similar)
• Unit, component, and end-to-end testing habit
• Strong product judgment
• Expert use of agentic coding tools such as Claude Code, Cursor, or Codex
• Hands-on experience shipping LLM features including prompt design, tool calling, and RAG
• Experience running evals and tracing production LLM traffic
• Understanding of cost, latency, and quality trade-offs in LLMs

Nice to have

• Next.js is a strong plus
• Healthcare, benefits, or other regulated-data experience (HIPAA, SOC 2)
• Building MCP servers or internal agent tooling for a team
• Experience with Clerk, Stripe, or Sentry
• Contributions to AI developer tooling, open source or internal

Benefits

• Equity
• Health, dental, and vision
• 401(k)
• Unlimited PTO

About the company

Marvin helps people navigate their mental health and wellbeing. They partner with employers and health plans to provide members a place to understand coverage, find care, and get support via an AI coach.