Senior Back-end Developer Python CDI Barcelona

This year marks 10 years since we launched the idea that simplifying our customers lives is possible by offering an innovative solution that allows them to easily subscribe to manage and switch all types of contracts through a unique and intuitive platform.

In that time we have supported more than 1.5 million customers in France Spain and Italy while investing in new verticals and positioning ourselves as a highly efficient innovative and competitive scale-up in a rapidly growing market.

With over 900 employees across 3 locations we are solidifying our position as a market leader in Europe. We are always on the lookout for talent ready to join a dedicated and motivated team driven by a meaningful project. Working with us means embracing a culture of excellence innovation and real impact.

As a Senior Backend Engineer you will play a key role in strengthening and scaling the technical foundations of our Spanish market operations.

Your responsibilities :

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 companys strategic objectives.

Your mission includes:

• 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

This role requires a hands-on senior engineer who combines strong technical expertise with business awareness thrives in evolving environments and takes ownership of delivering sustainable solutions that enable growth.

Your profile :

• Bachelors or Masters degree in Computer Science Software Engineering or equivalent practical experience.

• 5 years of backend development experience including senior-level ownership of architecture and integrations.

Technical Expertise:

• 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.

Your Strenghts:

• 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.

What We Offer You:

Evolve in an international and inclusive environment: Everyone has a place at papernest and with over 46 nationalities its common to start a sentence in French and finish it in English or Spanish!

Compensation: receive Subscription Bonuses for Company Creators (BSPCE) from your first day in line with company regulations.

Benefits: as a provider of home insurance and green energy we offer our employees attractive deals. After all it shouldnt be just our clients who benefit!

Health: enjoy mutual health insurance through Alan offering simple paper-free management of your healthcare expenses with 50% covered by papernest.

Meals: access the Swile card for meal vouchers valued at 9 per working day with 50% covered by papernest. Plus enjoy breakfast every Tuesday at the office a fully stocked Ideal Garden refrigerator and discounted rates at partner restaurants for healthy balanced meals.

Training: your growth is our priority. Youll have continuous training aligned with your goals whether in technical language or managerial skills.

Career Development: numerous opportunities await you to deepen your expertise or explore new directions. Were here to support your professional goals.

Remote Work: take advantage of 2 remote work days per week to enhance your focus and productivity.

Legal Advice: access the Ekie solution for dedicated legal and tax advice helping you manage all your procedures with peace of mind!

Hiring process:

First call with Wolfgang from the Talent team.

An interview with Sophie our Engineering Manager.

A technical test and a code review with the Tech team.

A last interview with Raphaël our CTO.

Interested in this challenge

Dont hesitate any longerwe look forward to meeting you! Regardless of your age gender background religion sexual orientation or disability theres a place for you with us. Our selection processes are designed to be inclusive and our work environment is adapted to everyones needs.

We particularly encourage applications from women. Even if you feel that you dont meet all the criteria outlined in this job posting please know that every application is valuable. We strongly believe that diverse and varied backgrounds enrich our team and we will carefully consider your application. Parity and diversity are essential assets to our success.