Full Stack Engineer

Pillar; Bellprat; On-site; EUR 55,000 - 75,000; Full time

Job summary

Pillar is hiring a product-minded Full Stack Engineer with backend depth to build the core of our platform in Milan or Barcelona. You will own features end-to-end, shaping backend data models, APIs, and product architecture while collaborating with frontend when needed.

Italian or Spanish native is mandatory, plus professional English. We value startup/scaleup experience, AI-native thinking, and the willingness to move fast in a small, autonomous squad as Pillar scales.

Qualifications

• Product engineer with backend depth and ownership.
• Experience in a startup or scaleup environment.
• Proficient with Next.js, React, and TypeScript; backend patterns.
• Supabase experience is a strong plus.
• Italian or Spanish native, plus professional English.

Responsibilities

• Own features end to end from problem to production.
• Build across TypeScript codebase using Next.js, React, Node/Deno, Postgres.
• Own backend logic, data models, APIs, integrations, and architecture.
• Contribute on frontend when needed with strong Next.js skills.
• Work in autonomous squads and apply AI-native workflows.

Skills

Backend depth

Product mindset

Startup/scaleup experience

AI-native thinking

Full-stack ownership

Next.js

React

TypeScript

Supabase experience

Node/Deno

Postgres

Tools

Next.js

React

TypeScript

Supabase

Node/Deno

Postgres

Mastra

AI-native workflows

Job description

About Pillar

Pillar was founded in 2025. Today, we are 80+ people, serve 900+ customers, raised €12 million in 2026, 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 product-minded Full Stack Engineer who leans backend, moves fast, and wants to build.

The Mission

Build product end to end, with particular strength on backend architecture and execution. Our frontend capability is already strong; we now want someone who can deepen the team on backend while still owning the full product picture.

What You'll Do

• Own features end to end, from product problem to production.

• Build across our TypeScript codebase using Next.js, React, Supabase, Node/Deno, Postgres, and Mastra.

• Take strong ownership of backend logic, data models, APIs, integrations, and product architecture.

• Work hands-on on the frontend when needed, with a strong preference for engineers comfortable with Next.js.

• Use AI as a native part of your engineering workflow - not only as a feature you build.

• Work in small squads with high autonomy and bottom-up initiatives.

• Move quickly from ambiguity to working product, making pragmatic technical decisions along the way.

• Raise the engineering bar through collaboration, judgment, and execution.

Our stack

• Product: Next.js · React · TypeScript

• Backend & data: Supabase · Node/Deno · Postgres

• AI: Mastra · AI-native workflows

Who You Are

A Product engineer with backend depth and high agency

• You are a product engineer: you build outcomes, not just code.

• You are stronger on backend or genuinely full stack. Pure frontend profiles are not our priority for this hire.

• You are comfortable with Next.js, React, TypeScript, and modern backend/data patterns. Supabase experience is a strong plus.

• You have worked in a startup or scaleup environment and understand the pace, ambiguity, and ownership it requires.

• You take initiative, get your hands dirty, and get things done without waiting for perfect instructions.

• You are AI-native: AI is already part of how you think, build, debug, learn, and move faster.

• You can zoom out to understand the full picture and zoom in when details matter.

• You learn from failure, communicate openly, and collaborate without ego.

• Native Italian or Spanish is mandatory, together with professional working English.

The Profile that Will Succeed

Backend-leaning · Product-minded · Startup DNA

The sweet spot: a hands-on product engineer from a startup/scaleup journey, ideally around the €3M-€30M growth stage, with backend depth and enough frontend fluency to own features end to end.

How we work

• Agile and squad-based: small teams own their domains, with no unnecessary layers.

• AI-first: we build and work in the age of AI.

• Full-stack ownership: engineers are hands-on and accountable for delivered value.

• Bottom-up: initiative is expected, not delegated.

What we offer

• Gross salary 55,000-75,000 €

• The opportunity to build core parts of Pillar's product and engineering foundations as we scale

• End-to-end ownership: from product decisions and architecture to shipping features used by real customers.

• The chance to work in an AI-native engineering team, where AI is part of both the product and the way we build it.

• Close collaboration with Product, AI, and Engineering, with direct exposure to the problems we are solving for customers.

• Real autonomy, responsibility, and room to grow as Pillar and the engineering team scale.

Location & languages

Milan or Barcelona; native Italian or Spanish (mandatory) plus professional English.

Hiring process

1. CV screening.

2. 30-min Talent Call - motivation, Pillar knowledge, mindset, languages, and startup fit.

3. Two 30-min Technical Interviews - one backend-focused touchpoint and one frontend/product-focused touchpoint with engineers from the team.

4. Final Interview with our CTO.

One last thing

Pillar is hiring this person while all of that is still taking shape.

Build the system behind the scale.