CareerOS is a B2B2C career platform serving 100+ top MBA programs worldwide - including Oxford, INSEAD, London Business School, Georgetown, and Notre Dame - along with 30+ employers. We help 500K+ users land jobs they love. We're a small, high-output team based in Barcelona, operating with American startup intensity - we ship fast, own our decisions, and push each other to do great work.
We work in small squads, each owning their own area of the product end-to-end.
We're looking for a Middle Full-Stack Engineer with a strong frontend focus who can work confidently across the stack - React/TypeScript on the frontend, Node.js/Go on the backend. You'll primarily build user-facing product experiences, ship features end-to-end, contribute to product decisions, and grow into a senior role with us.
What you'll actually do
You won't specialize in just one corner. You'll build across the stack, with your center of gravity on the frontend.
- Ship features end-to-end - From database to UI. You'll work across React/TypeScript and Node.js (with some legacy Go), owning features from start to finish.
- Make product decisions - See a confusing UX? Fix it. Have a better idea for an API design? Propose it and build it. We trust engineers to make smart calls on small-to-medium product decisions.
- Build with AI tools - We use AI coding tools daily (Claude Code, Cursor - team members pick what works for them). You should be comfortable (or excited) to work this way.
- Work directly with design - Implement pixel-perfect, responsive interfaces from Figma. Push back when something doesn't make sense.
- Own your code in production - We do continuous deployment. What you merge today is live today. You'll debug, monitor, and improve what you build.
What we're looking for
Must-haves:
- 2–4 years building production web applications, comfortable across frontend and backend
- Strong React and TypeScript skills - You can build complex UIs confidently
- Backend experience with Node.js or Golang - You can write APIs, work with databases, and debug across the stack
- Solid SQL skills - You can write queries, understand schemas, and think about data
- Strong product intuition - You've shipped features where you made design and technical calls, not just followed tickets
- Excellent communication - You can articulate tradeoffs clearly, push back respectfully, and work well async
- Comfortable with ambiguity - Requirements will be fuzzy. You ask the right questions, make reasonable assumptions, and move forward without hand-holding
- Fluent English - We're a distributed team; clear written and verbal communication is essential
Strong signals:
- You've worked at an early-stage startup before (and liked it)
- You have side projects or open source contributions that show you build things because you're curious
- You've used AI coding tools and have opinions about them
- You care about craft - clean code, good abstractions, thoughtful UI details
What this role is NOT
Let's be honest about fit:
- ❌ Not a laid-back 9-to-5 - Startup doesn't mean less oversight and more flexibility. It means more ownership, higher stakes, and sometimes intense pushes. We respect personal time, but when we ship, we ship hard.
- ❌ Not highly structured - If you need detailed specs and clear roadmaps to function, this isn't the place.
- ❌ Not single-track - If you only want to do frontend or only backend, check out our other roles. This one requires range.
What you get
- Competitive salary + stock options (based on experience and location).
- Remote-first setup with optional Spain-based employment.
- Small team where your work directly impacts 500K+ users.
- Direct access to founders and fast decision-making.
- Clear path toward Senior Engineer as we scale.
