Part 2

• Tech Lab

Full-Stack Engineer

Own products for years rather than weeks — build them properly, keep them alive, and make the agentic build method something a team can rely on.

• Barcelona
• Open
• 5 seats
• 1 senior, 4 junior

Apply for Full-Stack Engineer

What you own

• 01 Build, within the standard
• 02 Architecture for the product you own
• 03 Quality and the 100%-pass gate
• 04 The release

One method, many products

Mainloop is an engineering company in Barcelona. We own what we build and we answer to ourselves. You get the interesting part of a new company, with a real customer and real products from day one.

What we build is the software that automates professional-services work — across roughly fifteen countries, for businesses that are drowning in process. We work in two halves. One half goes into a business, works out what actually happens there, and builds a prototype fast enough to prove it is worth having. The other half — this half — takes that prototype and turns it into something a company depends on.



Most automation teams only have the first half, which is why most of them have a drawer full of demos and nothing in production.

We are hiring the engineers for the second half.

We are hiring at two levels, and we would rather say so than let you guess. There are four junior seats and one senior seat. The junior seats are open to people coming out of university and to young engineers generally — what we are looking for there is not a track record, it is appetite: you want to get very good very fast, and you have already been building with coding agents (Claude Code, Cursor, Codex or similar) because you found them interesting rather than because someone told you to. The senior seat is for someone who has owned production software for years and is ready to set the architecture others build inside. Apply to the same ad either way — tell us which one you think you are, and we will talk about it in the first conversation.

What the job actua

📌 Full-Stack Engineer (Barcelona)
🏢 Mainloop AI
📍 Barcelona