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OpenRouter Logo OpenRouter · IT - Software Development

Senior Full-Stack Engineer

United States · Job Posted February 21, 2026
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Job Description

OpenRouter is the world’s largest marketplace of LLMs, growing rapidly to meet the evolving needs of developers, enterprises, and AI enthusiasts. As part of our small, highly technical team of 10, we are looking for a Senior Full-Stack Engineer who thrives on shipping user-facing features, building elegant front-end interfaces with React, and creating powerful backend API functionality. This role is ideal for engineers who love autonomy, value collaboration, and have a track record of shipping software that works. You’ll play a critical role in shaping our product as we scale, helping expand our platform’s features, and delivering exceptional experiences for our users. We work asynchronously over Slack, Notion, and Linear, protecting uninterrupted time to build.

Job Responsibility

  • Front-End Development: Build and maintain user-friendly, high-performance interfaces using React and Next.js
  • API Development & Backend Work: Design, implement, and deploy scalable API functionality using Cloudflare Workers and edge-first architectures
  • End-to-End Product Ownership: Take features from concept to production
  • Maintain High Standards: Write clean, maintainable, and well-documented TypeScript code, contribute to code reviews
  • Problem Solving & Scalability: Identify bottlenecks, build great monitoring, propose solutions, and optimize performance across both frontend and backend systems

Requirements

  • 4+ years of professional experience in full-stack development, including shipping user-facing features and working with modern front-end frameworks
  • Proficient in React, TypeScript, Next.js, and JS runtimes
  • Bonus points for experience with Cloudflare Workers or other edge-first serverless platforms
  • Startup mindset: thrive in fast-paced, ambiguous environments, resourceful, proactive, comfortable taking ownership of projects end-to-end
  • Collaborative & Autonomous: strong communication skills, team-oriented attitude, can self-manage and deliver high-quality results while working asynchronously
  • Craftsperson's Approach: care deeply about user experience, performance, and maintainability, goal is to ship delightful and impactful features

Nice to have

Experience with Cloudflare Workers or other edge-first serverless platforms

What we offer

  • Attractive salary, equity, and benefits
  • Cutting-Edge Work: Be at the forefront of AI and LLM infrastructure
  • Small, Talented Team: Work closely with a tight-knit group
  • Growth Opportunities: Grow into leadership roles or specialize further
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