{"id":1899522,"url":"https://alion.io/job/t-systems-iberia-lead-senior-backend-engineer-mfd-2","title":"Lead Senior Backend Engineer (m/f/d)","company":{"id":8739,"name":"T-Systems Iberia","domain":"t-systems.es","url":"https://alion.io/company/t-systems-iberia","size_band":"5000+","is_staffing_agency":false,"employer_type":"services","is_intermediary":false,"listed_via":null,"ats_vendor":"SmartRecruiters","truth_index":null},"role":"Backend","role_family":"Backend","seniority":"lead","employment_type":"full_time","work_mode":"hybrid","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["A Coruña, Spain"],"countries":["ES"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":{"min_usd":62000,"max_usd":143000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":11},"experience_years_min":5,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"API Gateway","optional":false},{"name":"AWS","optional":false},{"name":"Azure","optional":false},{"name":"C++","optional":false},{"name":"CI/CD","optional":false},{"name":"Django","optional":false},{"name":"Docker","optional":false},{"name":"FastAPI","optional":false},{"name":"Flask","optional":false},{"name":"GCP","optional":false},{"name":"Go","optional":false},{"name":"gRPC","optional":false},{"name":"Java","optional":false},{"name":"Kubernetes","optional":false},{"name":"Python","optional":false},{"name":"Rest API","optional":false},{"name":"Rust","optional":false},{"name":"SGLang","optional":false},{"name":"SQL","optional":false},{"name":"TensorRT-LLM","optional":false},{"name":"vLLM","optional":false},{"name":"WebSockets","optional":false},{"name":"GitOps","optional":true},{"name":"Grafana","optional":true},{"name":"OpenTelemetry","optional":true},{"name":"Prometheus","optional":true},{"name":"RAG","optional":true},{"name":"TensorRT","optional":true}],"status":"live","first_seen_at":"2026-10-05T09:15:43Z","employer_posted_date":"2026-10-05","last_verified_at":"2026-11-05T23:25:11Z","board_verified":true,"closed_at":null,"days_open":31,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":31},"description":"T-Systems is part of the Deutsche Telekom Group, with around 30.000 employees worldwide. We create technology with purpose to generate a positive impact on society. We are looking for curious talent, eager to learn, take on challenges, and contribute ideas that transform our customers’ experience.\nWe trust people: we offer autonomy, continuous support, and a collaborative environment where you can grow without limits. We are one global team, guided by respect, integrity, and a passion for doing better every day.\n T-Systems is at the forefront of innovation, delivering advanced technology solutions across sectors including automotive, healthcare, and public services. Our AI Foundation Services team builds the platform infrastructure that powers AI inference at scale, including API gateways, authentication, billing, and multi-tenant serving.designs and builds high-performance backend systems and APIs that power intelligent applications across diverse industries. We cultivate a collaborative engineering culture where technical depthcreativity and ownership technical expertise drive real-world impact.\nRole Overview\nWe are looking for a senior backend engineer highly skilled Python Developer with strong system design skills and experience building production infrastructuredeep experience designing, building, and scaling distributed systems and APIs. In this role, YyYou willou will own architect and drive the evolution of the maintain backend platform behind our AI inference endpoints - a multi-tenant system handling authentication, API key management, usage metering, billing and request proxyservices that enable high-availability, data-intensive AI-powered solutions. The role is high-ownership and you will shape architecture decisions, raise the bar of engineering quality and build systems that are performant, secure and observable at scale. You’ll collaborate with experts in AI infrastructure and data engineering to build robust, secure, and efficient systems that scale to millions of requests.\nResponsibilities and Duties\nDesign and build core platform services: API gateway, authentication, authorization, key rotation, and multi-tenant isolation.Design, implement, and optimize APIs and backend systems using Python frameworks such as primarily FastAPI (or Flask, or Django).\nArchitect and implement usage metering, billing integration, and rate limiting for inference endpoints.Build and maintain scalable, fault-tolerant microservices for data processing and AI integration.\nBuild and operate a high-throughput proxy/routing layer for AI model serving traffic.Collaborate with cross-functional teams to design system architecture and ensure seamless system interoperability.\nDesign telemetry and observability into the platform from the ground up - structured logging, distributed tracing, metrics, and alerting.Implement robust CI/CD pipelines, monitoring, and observability for high-performance production systems.\nDrive technical decisions on architecture, data modeling, and technology choices.Identify performance bottlenecks and drive improvements in reliability, scalability, and latency.\nEstablish engineering standards for the backend codebase: testing, code review, CI/CD, and deployment practices.Ensure best practices for security, compliance, and maintainability across the API lifecycle.\nCollaborate closely with the ML infrastructure team to integrate with model serving systems (e.g., NVIDIA Dynamo, vLLM, SGlang, TensorRT-LLM).\n Must-have requirements:\nDegree in Computer Science, Software Engineering, or equivalent professional experience.\n5+ years of experience building and operatingdeveloping backend systems in production, with a meaningful scale with a focus on API design and high-scale production environments.\nStrong proficiency in Python and at least one systems-oriented language (Go, Rust, Java, C++), willingness to work across the current stack which includes Python (FastAPI) - we value the right tool for the jobengineer with deep knowledge of asynchronous programming, modern Python tooling and profiling.\nProven experience designing and maintaining REST APIs (REST, gRPC, WebSockets, SSEIncluding websockets, SSE, Webhooks etc.) in production environments and the tradeoffs between them.\nSolid understanding of distributed systems: consistency, fault tolerance, concurrency, performance and networking, data pipelines, and performance optimization.\nExperience designing authentication/authorization systems (OAuth2, JWT, API key management, RBAC/ABAC).\nExperience with cloud infrastructure (AWS, GCP, or Azure) and containers ized environments (Docker) and orchestration (, Kubernetes).\nUnderstanding of database design (SQL, ORMs etc.) and data modeling at scale.\nFluent in English (written and verbal) and comfortable collaborating in international teams.\nNice-to-have requirements:\nExperience with high-throughput, low-latency or real-time systems (e.g., message queues, event-driven architectures).\nFamiliarity with generative AI or large language models (e.g., integration of AI APIs, RAG workflows, or vector databases).\nExperienceKnowledge of in modern DevOps practices, infrastructure as code, GitOps workflows and observability tools (Prometheus, Grafana, OpenTelemetry).\nExposure to ML serving infrastructure (model servers, GPU scheduling, inference optimization) is a plus but not required.\nComfortable occasionally touching or contributing to frontend code when necessary.\nExperience in stress/load-testing and evaluating performance of production systems.\nStrong problem-solving mindset and commitment to code quality and performance excellence.\nTrack record of improving engineering culture: mentoring junior engineers, introducing better practices, leading technical discussions.\n What do we offer you?\nWork environment & flexibility\nInternational, dynamic and collaborative environment \nT-Social: social initiatives (sports, community, health, ...)\nHybrid work model (remote/on-site)\nFlexible working hours\nGrowth & development\nCustomized training: access to Coursera to learn whatever you want, whenever you want\nWeekly language classes (English, Spanish & German)\nInternational Mentoring Sessions & Experience Days\nCompensation & benefits\nFlexible compensation plan (health insurance, meal vouchers, childcare, transport)\nTelemedicine\nLife and accident insurance\nSocial fund\nWellbeing & time off\n26+ working days of vacation per year\nFree access to specialist services (medical, legal, wellness)\n100% salary coverage during medical leave\nAnd many more advantages of being part of T-Systems!\nIf you are looking for a new challenge, do not hesitate to send us your CV! Please send CV in English. Join our team!\nT-Systems Iberia will only process the CVs of candidates who meet the requirements specified for each offer.","description_format":"text","description_chars":6808,"description_truncated":false,"requirements":{"experience_years_min":5,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":{"level":"bachelor","optional":false},"security_clearance":false,"languages":[{"language":"English","level":"Advanced (C1)","optional":false}]},"benefits":["Flexible schedule","Health insurance","Hybrid work"],"hiring_locations":[{"name":"Spain","iso":"ES","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Cloud Platforms (IaaS & PaaS)","IT Consulting & Digital Transformation","Systems Integrators","Enterprise Apps Implementation Partners"],"lifecycle":[{"event":"open","at":"2026-10-05T10:05:53Z"}],"visa":[],"liveness":{"score":64,"band":"ok","label":"Likely open","p_open":1,"p_active":0.857,"p_room":0.75,"age_days":30,"expected_fill_days":38,"reasons":["conf:2","velocity","win:late"],"computed_at":"2026-11-05T05:54:30Z"},"pay":null,"html_url":"https://alion.io/job/t-systems-iberia-lead-senior-backend-engineer-mfd-2","json_url":"https://alion.io/job/t-systems-iberia-lead-senior-backend-engineer-mfd-2.json","meta":{"generated_at":"2026-11-05T23:56:17Z","cache_seconds":300,"methodology":"https://alion.io/methodology","terms":"https://alion.io/terms","contact":"https://alion.io/contact","api":"https://alion.io/developers","about":"Alion is a live layer of people, companies and AI agents: who they are, whether they are real and active right now, what they do and how to work with them, readable by people and by agents and paid per call.","catalog":"https://alion.io/catalog.json","usage":{"tier":"crawler_verified","counted_by":"address","units_charged":1,"used_today":5494,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-11-06T00:00:00Z"}},"offers":[{"id":"company.slices","title":"One company in depth, by slice","status":"live","price":{"credits":0.02,"usd":0.002,"plus_per_slice":{"credits":0.05,"usd":0.005}},"unit":"per company, plus each slice with data","note":"the employer in depth","call":{"mcp_tool":"get_company","arguments":{"id":8739},"rest":"https://alion.io/mcp/rest/get_company?id=8739"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Ft-systems-iberia-lead-senior-backend-engineer-mfd-2"},{"id":"market.stats","title":"A market slice: pay, demand and time to fill","status":"live","price":{"credits":1,"usd":0.1},"unit":"per slice","note":"pay, demand and time to fill for this role and place","call":{"mcp_tool":"market_stats"},"human":"https://alion.io/catalog?offer=market.stats&for=job%2Ft-systems-iberia-lead-senior-backend-engineer-mfd-2"},{"id":"job.search","title":"Open jobs by role, technology, place, pay and visa","status":"live","price":{"credits":0.02,"usd":0.002},"unit":"per posting in a list","note":"similar open postings","call":{"mcp_tool":"search_jobs"},"human":"https://alion.io/catalog?offer=job.search&for=job%2Ft-systems-iberia-lead-senior-backend-engineer-mfd-2"},{"id":"company.verify","title":"Is this company real and active right now","status":"pilot","price":null,"unit":"per company","request":{"url":"https://alion.io/catalog/request","method":"POST","body":"{\"offer\": \"company.verify\", \"for\": \"job/t-systems-iberia-lead-senior-backend-engineer-mfd-2\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Ft-systems-iberia-lead-senior-backend-engineer-mfd-2"}],"agent":{"mcp":"https://alion.io/mcp/jobs","mcp_open":"https://alion.io/mcp/open","next":[{"tool":"get_job","arguments":{"id":1899522}},{"tool":"search_jobs","arguments":{"company":"t-systems.es","detail":"compact"}},{"tool":"match_people","arguments":{"job_id":1899522},"note":"people open to offers who fit this vacancy"}],"note":"The same data through MCP tools: https://alion.io/mcp/open needs no sign-in (compact searches, postings, people); https://alion.io/mcp with an Alion account has everything. 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