Full Stack Engineer

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 an
Engineer
who can work confidently across the full stack - React/TypeScript on the frontend, on the backend. You'll ship features end-to-end, make product decisions, and grow into a senior role with us.

What you'll actually do

You won't specialize in one corner. You'll build across the stack.

• Ship features end-to-end
• From database to UI. You'll work across React/TypeScript and (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:

• 3-5 years building production web applications
  , comfortable on both frontend and backend
• Strong React and TypeScript skills
• You can build complex UIs confidently
• Backend experience with
• 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 (we'll discuss based on experience and location)
• Remote-friendly, with optional in-person time in Barcelona
• Small team where your work visibly matters - we have 500K+ users and real revenue
• Direct access to founders and fast decision-making
• Clear path to senior engineer as we scale from 5 to 10+ engineers

How to apply

Send us:

1. Your CV/LinkedIn
2. A brief note on a feature you shipped end-to-end - what decisions did you make on both frontend and backend

Founders are reviewing every application.

Don't check every box but think you'd be great? Apply anyway. We care more about trajectory and taste than credentials.