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papernest Logo papernest · IT - Software Development

Senior Back-end Developer Python

Spain, Barcelona · Job Posted March 02, 2026
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Job Description

As a Senior Backend Engineer, you will play a key role in strengthening and scaling the technical foundations of our Spanish market operations. You will be responsible for designing, building, and evolving backend systems that support business growth, operational efficiency, and long-term scalability. Acting as a bridge between business operations and technology, you will translate operational requirements into reliable, maintainable, and scalable software solutions. In a dynamic and fast-evolving environment, you will bring structure and engineering rigor. You will contribute to architectural decisions, establish best practices, and ensure that backend systems are resilient, performant, and aligned with the company’s strategic objectives.

Job Responsibility

  • Designing and implementing scalable backend services and APIs
  • Improving system reliability, performance, and maintainability
  • Partnering closely with operations and business stakeholders to understand evolving needs
  • Driving technical excellence and reducing technical debt through pragmatic decision-making
  • Contributing to architectural standards and long-term platform strategy
  • Supporting the scalability of our Spanish market by building robust, future-proof infrastructure

Requirements

  • Bachelor’s or Master’s degree in Computer Science, Software Engineering, or equivalent practical experience
  • 5+ years of backend development experience, including senior-level ownership of architecture and integrations
  • Senior-level expertise in Python (Django/FastAPI), including event-driven or asynchronous architectures
  • Strong experience managing complex API integrations and debugging data inconsistencies across multiple external services
  • Ability to reverse engineer semi-technical workflows (“shadow IT”) to understand business logic before leading refactoring
  • Strong analytical and problem-solving mindset
  • Pragmatic and structured approach in fast-moving environments
  • Fast learner of business domains with the ability to bridge technical and operational topics
  • Professional English required
  • Spanish is a plus

Nice to have

Spanish is a plus

What we offer

  • Subscription Bonuses for Company Creators (BSPCE) from your first day
  • Attractive deals on home insurance and green energy
  • Mutual health insurance through Alan, with 50% covered by papernest
  • Swile card for meal vouchers valued at €9 per working day, with 50% covered by papernest
  • Breakfast every Tuesday at the office
  • Fully stocked Ideal Garden refrigerator
  • Discounted rates at partner restaurants
  • Continuous training aligned with your goals
  • Career development opportunities
  • 2 remote work days per week
  • Access to the Ekie solution for dedicated legal and tax advice
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