About This Position

Tree-Nation has a platform, a database, running integrations, and active business units. You'll join a small, high-ownership tech team building and maintaining the Tree-Nation platform — the web app, the mobile app, the B2B tooling, the planting flows, and the integrations that tie it all together. This means backend services, APIs, data models, and the frontend interfaces that users and internal teams interact with. The team works without heavy process layers: you're expected to understand the product deeply, make good technical decisions, and take ownership of what you ship. You'll work closely with the rest of the engineers and directly with the people running the business, which means your work has a visible impact from day one.

What You'll Do

1. Build and maintain features across the Tree-Nation web platform (Vue.js + PHP) and mobile app (React Native) — frontend and backend, depending on where the work is.
2. Design and implement backend services, APIs, and database schemas that are clean, modular, and built to last.
3. Collaborate with the rest of the tech team on architecture decisions, code reviews, and technical problem-solving.
4. Diagnose before you build — map existing workflows, identify what's fragile or manual, and define system scope precisely before writing a line of code.
5. Own features end-to-end: design the data model, build the backend service, expose the API, and ship the frontend interface that makes it usable — without throwing work over a wall.
6. Prototype fast, then industrialize — using whatever stack solves the problem. Our backend is PHP, our frontend is Vue.js, and we also use TypeScript — but we don't have a sacred stack.
7. Own observability and failure handling from day one, not as an afterthought.
8. Use AI tools actively in your workflow — to prototype faster, improve code quality, and identify automation opportunities within your domain.

What You'll Bring

Required

1. Strong full-stack background — you've shipped production systems on both frontend and backend and you're genuinely comfortable on both sides.
2. Deep database design thinking: you model data before you write code and understand how schema decisions propagate into downstream behavior.
3. Experience with modular service architecture — systems that are scoped, isolated, composable, and replaceable.
4. Solid system design instincts: APIs, state management, integration patterns, failure handling, and observability.
5. Genuine full-stack experience: solid backend skills (PHP, RESTful APIs, database design) and confident frontend work (Vue.js, building interfaces that are actually pleasant to use).
6. Tool-agnostic approach — you choose the right tool for the problem and are comfortable building custom when off-the-shelf doesn't fit.
7. You diagnose before you prescribe — the right solution starts with the right question, and you can sit with ambiguity long enough to understand a problem fully before proposing a fix.
8. Based in Barcelona and comfortable working on-site.

Nice to Have

1. Experience with React Native — our mobile app is built on it, and any familiarity is a head start.
2. Practical exposure to LLM integration or automation workflows.

Mindset

1. High ownership — you take initiative, but you also know when to listen first. Tree-Nation does things differently, and the best people here understand context before trying to change it
2. Open and direct communicator — we give each other honest feedback because we want everyone to grow, and we expect the same openness in return.
3. Systems thinker — you look for the root cause, not the quick fix. You build processes that work at scale, not band-aids that break at 50 accounts
4. Self-driven and curious — you’re motivated by the impact of your work, and you actively seek out better ways to do things
5. Mission-aligned — reforestation isn’t a marketing line for you. It’s the reason you’re reading this

What We Offer

Compensation

1. Competitive base salary benchmarked to Barcelona’s tech market
2. Permanent contract

Benefits

1. Flexible Remuneration Card covering meals and transport
2. Wellhub (former Gympass) membership
3. Access a private health insurance plan at a preferential rate negotiated by the company.
4. Regular team-building events — dinners, offsites, and the occasional non-tree-related adventure
5. Flexible start time between 8:00 and 10:00 and short Fridays

The Tree-Nation Difference

1. Your lifetime carbon emissions are offset through monthly tree planting from the day you join
2. Personal tree-planting allocation to plant and gift trees, however you choose
3. A sustainability-designed office in Barcelona built to reflect the mission you’re working toward
4. A small, high-trust team where your work has a visible impact from day one — you’ll work directly with the CEO and Growth team, not through layers that filter your input
5. Direct exposure to product, tech, and strategic decisions
6. A place where failure is part of the process — if nothing is failing, we're not pushing hard enough

Round 1 - Interview with Head of Tech

Round 2- Technical Assessment

Round 3 - Assessment review

Round 4 - Meet the CEO and the team!