ppWe are thebIntelligent Internet Platform. /bWe connectbPeople, Places /bandbThings /banywhere,bmanaging Internet Performance /bbetter than anyone else while providingbOne Global Experience, /bgivingbVisibility, Control /bandbSecurity /bthroughbexpereoOne. /b /p pExpereo 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. /p pAs a trusted partner of Fortune 500 enterprises, our continued aim and success in helping our customers and partners depends solely on the talented individuals who make Expereo a dynamic, effective, multicultural, and equitable environment. /p h3About the role /h3 pWe 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. /p pYou will write Python and/or dotnet every day. You will work on an existing Python/C# backend and create new services. You will work on solving real-world business problems, like creating a constraint optimization engine, working on integrations with our partners and creating and maintaining internal tools. /p pThe core of the role sits at the intersection of three things: /p ul liAlgorithmic implementation — translating complex commercial requirements into deterministic, auditable logic. You will implement and maintain the optimization engine that drives our quote generation. /li liAPI design and contract maintenance — defining clear contracts between services, and ensuring the interface is clean, versioned, and reliable for downstream consumers. /li liCode quality and engineering discipline — making code production-ready and scalable: writing tests, applying engineering standards, and ensuring the codebase can grow with the platform. /li /ul pYou will work directly with the innovation and commercial teams. /p pThis role is also designed with growth in mind. 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. /p h3Key Responsibilities /h3 h3Business Logic Implementation /h3 ul liImplement and maintain business logic for the quote engine, partner integrations and internal services: supplier selection, service bundling, routing rules, product validation ... /li liExplore, document and integrate heterogeneous external data sources necessary to the execution of business logic. /li liEnsure all outputs are auditable, and explainable to commercial stakeholders — we don't build black boxes. /li liValidate model outputs against historical data; measure and report on prediction reliability. /li liOptimize the operational value of the integrations with our partners. /li /ul h3API Design Contract Maintenance /h3 ul liDefine contracts, manage versioning, and ensure downstream consumers are never broken silently. /li liWrite clear, well-documented API interfaces with explicit input/output contracts and error handling. /li liCoordinate with the Platform engineer on service integration and ensure clean separation of concerns between components. /li liMaintain API documentation as a living artifact, not an afterthought. /li /ul h3Code Quality Engineering Practices /h3 ul liRefactor and clean up existing Python/C# code: reduce complexity, increase testability, and bring the codebase up to production engineering standards. /li liWrite unit and integration tests that provide real confidence — not just coverage numbers. /li liApply Git, code review, and CI practices to all work. Code lives in a repository, goes through review, and is reproducible without intervention. /li liDocument non-obvious logic thoroughly so knowledge is transferable. /li /ul h3Collaboration Communication /h3 ul liPartner with the Commercial teams, Quote Engine lead Platform engineer — this is collaborative work, not ticket execution. /li liParticipate in sprint reviews, propose approaches,



and flag risks early. /li /ul h3Requirements /h3 pMust-Have /p ul liAdvanced Python — non-negotiable. Clean, tested, reusable code. Not just scripts that happen to work. /li liAPI design and implementation. Designing and maintaining REST APIs with clear contracts, versioning, and proper error handling. /li liSoftware engineering discipline. Testing, code review, Git, and the habits of someone who builds things that others can maintain. /li liAbility to work in a mixed-language codebase. The existing platform is Python/C#. You need to be comfortable reading it and understanding the integration points. /li /ul pStrong Plus /p ul liC#: You will also work with the existing platform, you need to write quality, clean, testable code in C#. /li liFamiliarity with AWS services (Lambda, API Gateway, S3) or equivalent cloud infrastructure. /li liExperience with API specification tooling (OpenAPI/Swagger, Pydantic, etc.). /li liExposure to Python packaging, dependency management, and CI pipelines. /li liFamiliarity with constraint-solving tools such as OR-Tools, PuLP, or equivalent in a real-world setting. /li liExperience in a B2B SaaS, telecom, or logistics context where algorithmic correctness has real commercial stakes. /li liComfort with performance profiling and optimization in Python. /li /ul h3Benefits /h3 ul liPart of a team that is engaged and owning the things they do, highly trustable with direct commercial stakes. /li liDirect access to production systems, real data, and decision-makers — no layers of process between your work and its impact. /li liExposure to cutting-edge technologies and large-scale integral networks. /li liA role designed with trajectory in mind — the knowledge you build here is directly applicable to a senior technical execution path. /li liCompetitive compensation /li liPension Plan /li liHybrid Working /lili25 Days Holidays /li /ul pWe are thebIntelligent Internet Platform. /bWe connectbPeople, Places /bandbThings /banywhere,bmanaging Internet Performance /bbetter than anyone else while providingbOne Global Experience, /bgivingbVisibility, Control /bandbSecurity /bthroughbexpereoOne. /b /p pExpereo 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. /p pAs a trusted partner of Fortune 500 enterprises, our continued aim and success in helping our customers and partners depends solely on the talented individuals who make Expereo a dynamic, effective, multicultural, and equitable environment. /p h3About the role /h3 pWe 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. /p pYou will write Python and/or dotnet every day. You will work on an existing Python/C# backend and create new services. You will work on solving real-world business problems, like creating a constraint optimization engine, working on integrations with our partners and creating and maintaining internal tools. /p pThe core of the role sits at the intersection of three things: /p ul liAlgorithmic implementation — translating complex commercial requirements into deterministic, auditable logic. You will implement and maintain the optimization engine that drives our quote generation. /li liAPI design and contract maintenance — defining clear contracts between services, and ensuring the interface is clean, versioned, and reliable for downstream consumers. /li liCode quality and engineering discipline — making code production-ready and scalable: writing tests, applying engineering standards, and ensuring the codebase can grow with the platform.



/li /ul pYou will work directly with the innovation and commercial teams. /p pThis role is also designed with growth in mind. 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. /p h3Key Responsibilities /h3 h3Business Logic Implementation /h3 ul liImplement and maintain business logic for the quote engine, partner integrations and internal services: supplier selection, service bundling, routing rules, product validation ... /li liExplore, document and integrate heterogeneous external data sources necessary to the execution of business logic. /li liEnsure all outputs are auditable, and explainable to commercial stakeholders — we don't build black boxes. /li liValidate model outputs against historical data; measure and report on prediction reliability. /li liOptimize the operational value of the integrations with our partners. /li /ul h3API Design Contract Maintenance /h3 ul liDefine contracts, manage versioning, and ensure downstream consumers are never broken silently. /li liWrite clear, well-documented API interfaces with explicit input/output contracts and error handling. /li liCoordinate with the Platform engineer on service integration and ensure clean separation of concerns between components. /li liMaintain API documentation as a living artifact, not an afterthought. /li /ul h3Code Quality Engineering Practices /h3 ul liRefactor and clean up existing Python/C# code: reduce complexity, increase testability, and bring the codebase up to production engineering standards. /li liWrite unit and integration tests that provide real confidence — not just coverage numbers. /li liApply Git, code review, and CI practices to all work. Code lives in a repository, goes through review, and is reproducible without intervention. /li liDocument non-obvious logic thoroughly so knowledge is transferable. /li /ul h3Collaboration Communication /h3 ul liPartner with the Commercial teams, Quote Engine lead Platform engineer — this is collaborative work, not ticket execution. /li liParticipate in sprint reviews, propose approaches, and flag risks early. /li /ul h3Requirements /h3 pMust-Have /p ul liAdvanced Python — non-negotiable. Clean, tested, reusable code. Not just scripts that happen to work. /li liAPI design and implementation. Designing and maintaining REST APIs with clear contracts, versioning, and proper error handling. /li liSoftware engineering discipline. Testing, code review, Git, and the habits of someone who builds things that others can maintain. /li liAbility to work in a mixed-language codebase. The existing platform is Python/C#. You need to be comfortable reading it and understanding the integration points. /li /ul pStrong Plus /p ul liC#: You will also work with the existing platform, you need to write quality, clean, testable code in C#. /li liFamiliarity with AWS services (Lambda, API Gateway, S3) or equivalent cloud infrastructure. /li liExperience with API specification tooling (OpenAPI/Swagger, Pydantic, etc.). /li liExposure to Python packaging, dependency management, and CI pipelines. /li liFamiliarity with constraint-solving tools such as OR-Tools, PuLP, or equivalent in a real-world setting. /li liExperience in a B2B SaaS, telecom, or logistics context where algorithmic correctness has real commercial stakes. /li liComfort with performance profiling and optimization in Python. /li /ul h3Benefits /h3 ul liPart of a team that is engaged and owning the things they do, highly trustable with direct commercial stakes. /li liDirect access to production systems, real data, and decision-makers — no layers of process between your work and its impact. /li liExposure to cutting-edge technologies and large-scale global networks. /li liA role designed with trajectory in mind — the knowledge you build here is directly applicable to a senior technical execution path. /li liCompetitive compensation /li liPension Plan /li liHybrid Working /li li25 Days Holidays /li /ul /p #J-18808-Ljbffr

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