We are theIntelligent Internet Platform.We connectPeople, PlacesandThingsanywhere,managing Internet Performancebetter than anyone else while providingOne Global Experience,givingVisibility, ControlandSecuritythroughexpereoOne.Expereo believes in the power of Internet connectivity. As the world's largest provider of managed internet, SD-WAN/SASE, and Cloud connectivity solutions, we power enterprises and government sites worldwide, helping to enhance every business' productivity with flexible and optimal Internet performance.About the roleWe are looking for a Backend Developer to join the Supplier onboarding and Quote Management teams and work directly on the computational core of our platform.You will write Python and/or dotnet every day. You will work on an existing Python/C# backend and create new services.

Algorithmic implementation — translating complex commercial requirements into deterministic, auditable logic. API design and contract maintenance — defining clear contracts between services, and ensuring the interface is clean, versioned, and reliable for downstream consumers.Code quality and engineering discipline — making code production-ready and scalable: writing tests, applying engineering standards, and ensuring the codebase can grow with the platform.You will work directly with the innovation and commercial teams.The knowledge and context you build here — deep familiarity with the platform, the commercial logic, and the constraints of the business — make this a natural stepping stone toward a technical execution role, potentially supporting a commercial STO (single thread owner) function as the platform scales.Explore, document and integrate heterogeneous external data sources necessary to the execution of business logic.Ensure all outputs are auditable, and explainable to commercial stakeholders — we don't build black boxes.Validate model outputs against historical data; API Design & Contract MaintenanceDefine contracts, manage versioning, and ensure downstream consumers are never broken silently.Code Quality & Engineering PracticesRefactor and clean up existing Python/C# code: reduce complexity, increase testability,



and bring the codebase up to production engineering standards.Write unit and integration tests that provide real confidence — not just coverage numbers.Partner with the Commercial teams, Quote Engine lead Platform engineer — this is collaborative work, not ticket execution.We are theIntelligent Internet Platform.We connectPeople, PlacesandThingsanywhere,managing Internet Performancebetter than anyone else while providingOne Global Experience,givingVisibility, ControlandSecuritythroughexpereoOne.Expereo believes in the power of Internet connectivity. As the world's largest provider of managed internet, SD-WAN/SASE, and Cloud connectivity solutions, we power enterprises and government sites worldwide, helping to enhance every business' productivity with versátil and optimal Internet performance.About the roleWe are looking for a Backend Developer to join the Supplier onboarding and Quote Management teams and work directly on the computational core of our platform.You will write Python and/or dotnet every day.

You will work on an existing Python/C# backend and create new services. Algorithmic implementation — translating complex commercial requirements into deterministic, auditable logic. API design and contract maintenance — defining clear contracts between services, and ensuring the interface is clean, versioned, and reliable for downstream consumers.Code quality and engineering discipline — making code production-ready and scalable: writing tests, applying engineering standards, and ensuring the codebase can grow with the platform.You will work directly with the innovation and commercial teams.The knowledge and context you build here — deep familiarity with the platform, the commercial logic, and the constraints of the business — make this a natural stepping stone toward a technical execution role, potentially supporting a commercial STO (single thread owner)



function as the platform scales.Explore, document and integrate heterogeneous external data sources necessary to the execution of business logic.Ensure all outputs are auditable, and explainable to commercial stakeholders — we don't build black boxes.Validate model outputs against historical data; API Design & Contract MaintenanceDefine contracts, manage versioning, and ensure downstream consumers are never broken silently.Code Quality & Engineering PracticesRefactor and clean up existing Python/C# code: reduce complexity, increase testability, and bring the codebase up to production engineering standards.Write unit and integration tests that provide real confidence — not just coverage numbers.Collaboration & CommunicationPartner with the Commercial teams, Quote Engine lead Platform engineer — this is collaborative work, not ticket execution.RequirementsMust-HaveAdvanced Python — non-negotiable.

Clean, tested, reusable code. Software engineering discipline. Testing, code review, Git, and the habits of someone who builds things that others can maintain.The existing platform is Python/C#. You need to be comfortable reading it and understanding the integration points.Strong PlusC#: You will also work with the existing platform, you need to write quality, clean, testable code in C#.

Familiarity with AWS services (Lambda, API Gateway, S3) or equivalent cloud infrastructure.Exposure to Python packaging, dependency management, and CI pipelines.Experience in a B2B SaaS, telecom, or logistics context where algorithmic correctness has real commercial stakes.Comfort with performance profiling and optimization in Python.BenefitsPart of a team that is engaged and owning the things they do, highly trustable with direct commercial stakes.Direct access to production systems, real data, and decision-makers — no layers of process between your work and its impact.Exposure to cutting-edge technologies and large-scale global networks.A role designed with trajectory in mind — the knowledge you build here is directly applicable to a senior technical execution path.Competitive compensationPension PlanHybrid Working25 Days Holidays #

📌 Senior Backend Developer (Python) (Barcelona)
🏢 Expereo International
📍 Barcelona