Full Stack Engineer
Pillar
Full Stack Engineer
Pillar
AI-enabled construction project and finance management
Barcelona - Onsite
Pillar was founded in 2025. Today, we are 90+ people, serve 1000+ customers, raised €15.2M (pre-seed and seed round) and are expanding internationally.
We are building the financial operating system for construction: bringing AI, automation and modern software to an enormous industry still full of slow, fragmented processes.
We are looking for a backend-leaning Full Stack Engineer who has built product in a startup or scaleup, loves strong data models and wants to own features end to end.
The mission
Build product end to end, with particular strength on backend architecture and execution.
What you will do
Own features end to end, from the customer problem to production.
Design data models, APIs and integrations behind payments, invoices and project finances.
Raise the bar on backend architecture across our TypeScript codebase.
Work on the frontend in Next.js and React when the feature needs it.
Use AI as a native part of how you build, debug and learn.
Who we are looking for
You have built product in a startup or scaleup, ideally in the €3M to €30M growth stage, as part of a team of engineers and designers.
You are strong on backend and databases, and you can explain why you made each choice, not just what you built.
You are comfortable with Next.js, React, TypeScript, Postgres and modern backend patterns. Supabase is a strong plus.
You have enough frontend fluency to own a feature end to end. Pure frontend profiles are not our focus for this hire.
You understand an existing architecture before reshaping it, and you are open to patterns different from yours.
You challenge ideas, accept trade-offs and make the people around you better.
You are AI-native: AI is already part of how you build.
Native Italian or Spanish, plus professional English. Based in Barcelona or willing to relocate
How we work
Small squads, high autonomy, no unnecessary layers.
AI-first, in the product and in the way we build.
Bottom-up: initiative is expected, not delegated.
Pillar is not for you if you prefer to decide alone, or if you want to work only on frontend.
Hiring process
01 CV screening
02 30-min People call with Marta
03 30-min backend conversation with one of our engineers
04 30-min frontend and product conversation with another engineer
05 Final conversation with our CTO
What we offer
Gross salary 65.000-80.000 €, based on experience
Real ownership: from product decisions and architecture to features customers use every day
A company that moves fast: 90+ people and 1000+ customers in under two years
An AI-native team: AI is part of the product and of how we build it
Close to customers: direct exposure to the problems we solve, with Product, AI and Engineering
People who care: a team that celebrates wins together, gives honest feedback and has fun along the way.
Pillar builds AI-powered management software for construction, combining finances, operations, and site data in one platform so owners see costs and earnings per job. Pillar AI is a chat-style assistant that lets a contractor manage business and site activity in one place, answering questions from cash flow to hours worked, with modules for cash-flow tracking, site reports, invoicing, quotes, bill of quantities, and job-order management with margins, costs, and hours. Additional modules cover procurement and safety, plus free calculators, case studies, blog, and webinars; it targets small and medium builders and uses a subscription model with demos via the website. Pillar differentiates by tying site activity directly to finances through AI-assisted workflows and an integrated single platform, aiming to simplify back-office tasks and make them data-driven so builders run more transparently and profitably.
Explore more opportunities at Pillar