Senior Full-Stack Engineer

About the Role:

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 5, 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. If you’re passionate about crafting high-quality software, working with cutting-edge technology, and helping us create an impactful AI infrastructure company, we’d love to hear from you.

Key Responsibilities:

• Front-End Development:
  Build and maintain user-friendly, high-performance interfaces using React and Next.js. Translate designs into smooth, functional experiences for our diverse user base.

• API Development & Backend Work:
  Design, implement, and deploy scalable API functionality using Cloudflare Workers and edge-first architectures. Ensure robust backend systems to support our platform's rapid growth.

• End-to-End Product Ownership:
  Take features from concept to production, ensuring they are performant, reliable, and delightful for users. Make good product and design decisions, and be open to feedback and collaborative creation.

• Maintain High Standards:
  Write clean, maintainable, and well-documented TypeScript code. We believe in good types! Contribute to code reviews, bring your experience, and uphold best practices to elevate the team.

• Problem Solving & Scalability:
  Identify bottlenecks, build great monitoring, propose solutions, and optimize performance across both frontend and backend systems.

About You:

• Experience:
  4+ years of professional experience in full-stack development, including shipping user-facing features and working with modern front-end frameworks.

• Technical Expertise:
  Proficient in React, TypeScript, Next.js, and JS runtimes. Bonus points for experience with Cloudflare Workers or other edge-first serverless platforms.

• Startup Mindset:
  You thrive in fast-paced, ambiguous environments. You're resourceful, proactive, and comfortable taking ownership of projects end-to-end.

• Collaborative & Autonomous:
  Strong communication skills and a team-oriented attitude. You can self-manage and deliver high-quality results while working asynchronously.

• Craftsperson's Approach:
  You care deeply about user experience, performance, and maintainability. Your goal is to ship delightful and impactful features, not just code.

What We Offer:

• Cutting-Edge Work:
  Be at the forefront of AI and LLM infrastructure, building tools for developers and enterprises alike.

• Small, Talented Team:
  Work closely with a tight-knit group of top-notch engineers who value excellence and innovation.

• Growth Opportunities:
  As we scale, grow into leadership roles or specialize further in your area of interest.

• Competitive Compensation:
  Attractive salary, equity, and benefits that reflect the impact you’ll have on our success.