Our client, a fast-growing international startup, is redefining how people unlock the value of what they already own, turning circularity into a smart, frictionless payment experience. With a live product, real traction, and a modern tech stack, they are expanding their engineering team with a senior backend profile who enjoys building scalable, resilient systems that have a direct impact on business.
If you’re motivated by real technical challenges, modern architecture, and building AI-driven features from the ground up (not just buzzwords), keep reading.
The Role
The selected candidate will join an agile team with real autonomy. Core responsibilities include:
Designing and building scalable backend systems (Python + Django REST Framework).
Working on complex integrations across payments, ecommerce, logistics, and automation.
Participating in architectural decisions and technical roadmap definition.
Driving engineering quality through testing and TDD practices.
Mentoring teammates and contributing to product direction.
Helping build the AI infrastructure from scratch.
What We’re Looking For
Technical Background
5+ years of backend development experience (senior or lead level).
Strong experience with Python and Django REST Framework (or similar: Ruby on Rails, Phoenix, Laravel, etc.).
Strong testing mindset (ideally TDD).
Knowledge of PostgreSQL, AWS, and security best practices.
Comfortable with occasional frontend work (while remaining backend-focused).
Solid understanding of system design and scalability.
Product & Business
Genuine curiosity about how users experience the product.
Ability to translate design specs into actionable engineering tickets.
Interest in understanding the why, not just the what.
AI
Interest in AI for productivity (code generation, automation).
Excitement about building AI features and infrastructure from scratch.
Curiosity about emerging AI capabilities.
Communication
Fluent in English (spoken and written). Spanish is a plus.
Pragmatic problem-solver who balances speed and quality.
Collaborative mindset with mentoring experience.
Bonus
Experience in fintech, payments, or ecommerce.
Tech Stack
Backend: Python, Django REST Framework
Database: PostgreSQL
Frontend: Angular / Vanilla JS
Integrations: PHP (ecommerce plugins)
What the Company Offers
Competitive compensation.
Fully remote role (optional hub in Barcelona).
Flexibility: 5-hour overlap with Spanish business hours (9–19 CET).
High autonomy in both technical and product decisions.
Opportunity to build AI infrastructure from zero.
Growing team with strong technical leadership.