Backend Engineer

About Free

At Free, you'll find a unique and strong internal culture. There's a strong collective spirit. Recruitment is open, without prejudice: we don't judge people on their age or background.

We like to move fast, do things ourselves, and we rely on autonomy to be effective. You'll see: at Free, we feel free!

Job Description

As part of an ambitious program to modernize and evolve its technical platforms, Free is strengthening its Backend teams. You'll join the team in charge of two critical areas for Free Mobile's 17 million subscribers:

• Banking / Payment: transaction management, direct debits, defaults
• Logistics: order management, shipping, equipment returns

Missions & Responsibilities

Technical Leadership (60%)

Architecture & Structuring Decisions

• Define the architecture of highly available distributed systems
• Arbitrate technical choices for payment and logistics areas
• Ensure the scalability, resilience, and performance of solutions
• Ensure technical consistency within the SI One project

Hands-on Development

• Code on critical and complex topics (Java/Spring Boot)
• Perform code reviews and pair programming
• Implement best practices (testing, CI/CD, observability)

Business Expertise

• Develop a deep understanding of complex business processes (3DS payment, SEPA/IBAN, subscription management, e-commerce logistics)
• Liaise with business and product teams to translate needs into technical solutions

Team Management (40%)

Management of a small, effective team (2 seniors + 1 junior)

Animation & Development

• Regular 1-to-1s, continuous feedback
• Define individual and collective objectives
• Recruit new talents (backend Java/Spring Boot profiles)
• Organize work: task distribution, prioritization, planning
• Ensure team cohesion and motivation

Velocity and Quality Management

• Ensure project delivery on time
• Guarantee the quality of code and deployed solutions
• Monitor performance indicators (availability, response time, incidents)
• Continuous improvement of development practices

Technical Stack & Areas

Technologies: Java 8-25, Spring Boot, JBoss 6, MySQL, Hibernate, REST/SOAP API

Functional Scope:

• 3D Secure Payment (enrollment tunnel, account management)
• Payment management at terminals (in-store subscription)
• SEPA/IBAN payment for direct debits via BNPP partner
• Management of SEPA direct debit defaults
• Integration with PSP and banking systems

Constraints: 24/7 High Availability, Real-time, Critical Performance, PCI-DSS Security

Logistics Scope:

Functional Scope:

• Order management: mobile phones, SIM cards (B2C), Freecenter (B2B)
• Shipping of invoices and letters
• Equipment return management
• Integration with WMS/OMS and carriers

Constraints: High Volume, Data Integrity, Complete Traceability

Qualifications

Profile Sought

• Minimum 7-10 years of backend development
• 3+ years of experience in management or technical leadership
• Significant experience on at least one long project (2+ years) demonstrating stability and ability to evolve a system

Essential Technical Skills

Backend & Architecture

• Java/Spring Boot expertise (confirmed senior level)
• Highly available and high-performance distributed systems
• REST/SOAP API design
• Relational databases (MySQL, PostgreSQL, Oracle)
• ORM (Hibernate, JPA)

Essential Soft Skills

Leadership & Management

• Ability to unite and grow a team
• Caring and empathetic leadership
• Clear and educational communication

Mindset

• Autonomy and ability to work without constant supervision
• Pragmatism and results-oriented
• Technical curiosity and technological watch
• Ability to communicate and share with business teams
• Strong team spirit

We are looking for a profile that never gives up: passionate, resourceful, capable of seeing a technical problem through to the end.

Someone who likes to understand, test, break, and fix until it works.

A role tailored for curious and demanding minds who want concrete results.

Do you see yourself in this description? Apply! 👇

Recruitment Process

1. HR Exchange – 30 min with the recruiter (Video call)
2. Pre-selection test (to be done at home)
3. Technical simulation – Concrete case (on-site)
4. Technical interview with a Manager
5. Final interview

Additional Information

Benefits & Free Culture

Package

• Salary based on profile: (to be negotiated based on experience)
• Profit-sharing and participation linked to the performance of the Iliad Group
• Reimbursement of your Freebox
• Swile meal vouchers: €10/day (60% covered by Free)
• Transport reimbursement: up to 70%
• Advantageous health and welfare coverage
• Time Savings Account (CET)
• CSE benefits: gift vouchers, discounts, exclusive offers

The Iliad group is fully committed to its employees through a strict policy of non-discrimination and anti-harassment. All applications are welcome, regardless of background, age, origin, gender, or sexual orientation.