CareerOS

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, Node.js 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 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:

• 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 Node.js - 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

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.

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 Full-Stack Engineer who can work confidently across the full stack - React/TypeScript on the frontend, Node.js/Go 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 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:

• 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 Node.js - 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)
• Preferred on-site in Barcelona with offical Spanish employment
• 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

Junior Engineer (Frontend)

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 Junior Engineer who's strong on frontend and eager to grow into a full-stack developer. You'll ship real features from day one, learn fast, and work alongside senior engineers who'll help you level up.

What you'll actually do

You won't do busywork. You'll ship real features to real users.

• Build frontend features - React and TypeScript will be your main focus. You'll implement UIs, work with design, and ship features users interact with daily.
• Grow into full-stack - We expect willingness to work across the stack. You'll start touching Node.js APIs and databases as you get comfortable.
• 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 responsive interfaces from Figma. Ask questions when specs are unclear.
• Learn in production - We do continuous deployment. You'll see your code live quickly, learn from mistakes fast, and improve with each feature.

What we're looking for

Must-haves:

• 1-2 years of experience (or strong projects/bootcamp background) building web applications
• Confident with React and TypeScript - You can build UIs, manage state, and work with components
• Code quality - Knowledge of SOLID principles and clean code practices
• User focus - You have a strong sensibility for UI and UX and understand what makes a web application feel responsive and polished
• Willing to learn full-stack - You're curious about how the backend works and want to grow in that direction
• Good communication - You ask questions when stuck, share progress, and work well with others
• Comfortable with feedback - You take code review seriously and want to improve
• Fluent English - We're a distributed team; clear written communication is essential

Strong signals:

• Some backend experience with Node.js (even from side projects)
• You are familiar with React Native
• You have side projects or contributions that show you build things because you're curious
• You've used AI coding tools and are excited about them
• Bootcamp grad or self-taught with a strong portfolio
• You've worked in a fast-paced environment before

What this role is NOT

Let's be honest about fit:

• ❌ Not a laid-back internship - This is a real engineering job. You'll ship to production, own features, and be expected to deliver.
• ❌ Not highly structured - You'll get support and mentorship, but you need to be proactive about learning and asking for help.
• ❌ Not frontend-only - Frontend is your primary focus, but if you only want to implement user interfaces, this isn't the right fit.

What you get

• Competitive junior salary + stock options
• Fully remote - Work from anywhere (EU timezone preferred for overlap)
• Mentorship from senior engineers who want to help you grow
• Small team where your work visibly matters - we have 500K+ users and real revenue
• Direct access to founders and fast decision-making
• Clear growth path - we promote from within as we scale

How to apply

Send us:

1. Your CV/LinkedIn
2. A link to something you've built (side project, portfolio piece, or contribution) - tell us what you learned building it

No cover letter needed. We review every application.

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