Senior Backend Developer (Python)

About the role

Expereo, a provider of managed internet, SD-WAN/SASE and cloud connectivity solutions, is looking for a Backend Developer to join the Supplier onboarding and Quote Management teams. You will work directly on the computational core of the platform, writing Python and/or .NET daily on an existing Python/C# backend and creating new services. The role sits at the intersection of algorithmic implementation, API design and code quality, and is described as a stepping stone toward a technical execution role.

Key responsibilities

• Implement and maintain business logic for the quote engine, partner integrations and internal services (supplier selection, service bundling, routing rules, product validation), keeping outputs auditable and explainable to commercial stakeholders
• Integrate heterogeneous external data sources and validate model outputs against historical data
• Design and maintain REST APIs with clear contracts, versioning and error handling, and keep API documentation up to date
• Refactor existing Python/C# code, write unit and integration tests, and follow Git, code review and CI practices
• Work closely with the Commercial teams and the Quote Engine lead Platform engineer, taking part in sprint reviews

Required profile

• Advanced Python with clean, tested, reusable code
• Ability to work in a mixed Python/C# codebase
• Strong plus: C# coding experience
• Experience in a B2B SaaS, telecom or logistics context is a strong plus

Required skills

• REST API design and OpenAPI/Swagger or Pydantic
• AWS Lambda, API Gateway and S3 or equivalent cloud infrastructure
• Constraint-solving tools such as OR-Tools or PuLP
• Performance profiling and optimization in Python

What we offer

• Competitive compensation
• Pension plan
• Hybrid working
• 25 days holiday