About the Company

CareerOS is a B2B2C career platform serving more than 100 leading MBA programs worldwide, including Oxford, INSEAD, London Business School, Georgetown, and Notre Dame, as well as more than 30 employers. The platform helps over 500,000 users find jobs that match their goals.

Based in Barcelona, CareerOS operates with a small, high-output team that values fast execution, ownership, and thoughtful product decisions. Engineers work in small squads and take responsibility for their product areas from development through production.

About the Role

CareerOS is looking for a Full Stack Engineer with 3–5 years of experience building production web applications. You'll work across React and TypeScript on the frontend and Node.js on the backend, developing features from database design through to the user interface.

This role combines hands-on engineering with product decision-making. You'll collaborate directly with designers, improve user experiences, make technical recommendations, and use AI coding tools as part of your daily workflow. With a distributed team and continuous deployment practices, you'll take ownership of the code you ship and help improve it in production.

Key Responsibilities

• Build and ship end-to-end product features across React, TypeScript, Node.js, and databases, with some work involving legacy Go.
• Develop complex frontend interfaces and backend APIs.
• Write SQL queries, work with database schemas, and make sound data-related decisions.
• Identify confusing user experiences and implement improvements.
• Propose and make small-to-medium product and technical decisions, including API design.
• Build and refine responsive, pixel-perfect interfaces from Figma designs.
• Collaborate directly with designers, providing feedback and raising concerns when design decisions need reconsideration.
• Use AI coding tools such as Claude Code and Cursor to support development.
• Deploy code continuously and take responsibility for debugging, monitoring, and improving production features.
• Communicate technical trade-offs clearly and collaborate effectively across a distributed team.
• Work independently through ambiguous requirements by asking relevant questions, making reasonable assumptions, and moving projects forward.

Required Qualifications

• 3–5 years of experience building production web applications across both frontend and backend development.
• Strong React and TypeScript skills, including the ability to build complex user interfaces.
• Backend development experience with Node.js, including API development, database interaction, and debugging across the stack.
• Strong SQL skills, including writing queries and understanding database schemas.
• Good product judgment and experience making design and technical decisions while delivering features.
• Excellent written and verbal communication skills, with the ability to explain trade-offs and provide respectful feedback.
• Comfort working with ambiguity and moving forward without extensive specifications or close supervision.
• Fluent English for effective communication within a distributed team.

Preferred Qualifications

• Experience working at an early-stage startup.
• Side projects or open-source contributions that demonstrate curiosity and a hands-on approach to building software.
• Experience using AI coding tools and the ability to assess their strengths and limitations.
• A strong focus on code quality, clean abstractions, and thoughtful user interface details.

Work Environment and Expectations

CareerOS offers a remote-friendly working arrangement, with optional in-person time in Barcelona. Engineers work with significant ownership in a fast-moving startup environment where requirements may be open-ended and priorities can require intense periods of execution.

The role suits engineers who enjoy working across the stack, making independent decisions, collaborating directly with product and design, and taking responsibility for software in production. It is not designed for candidates who prefer narrowly defined frontend or backend responsibilities or highly structured specifications.

Compensation and Benefits

• Competitive salary based on experience and location.
• Stock options.
• Remote-friendly work, with optional in-person collaboration in Barcelona.
• A small team where individual contributions have a visible impact on a platform serving more than 500,000 users.
• Direct access to the founders and fast decision-making.
• A clear growth path toward a Senior Engineer role as the engineering team expands from five to more than ten engineers.