Reference: 1130785Job ID: 5422181Posted: 2026-10-27Closing date: 2027-01-26Location: Barcelona and 4 days home office per weekSalary: up to 50.000e gross anual + other benefits (per annum)Job type: PermanentIndustry: Tecnología e Internet / Software DeveloperCompany: HaysConsultant: Anna GarrigaHays office: Barcelona — Hays Barcelona, Calle Valencia, 307-313, bajos 1ªPhone: +34 664845467Email: [email protected] New CompanyOne of Europe’s leading consumer retailers is looking to hire a Backend Software Engineer to join one of the squads.Your New RoleDevelop and maintain services for customer order processing, covering the end-to-end online order journey.Build and manage APIs and integrations between the Order Management System and key corporate applications such as SAP, Checkout, Payments, Invoicing and Pick & Pack.Orchestrate order workflows to ensure consistent and real-time processing across different systems.Standardize order data and communication between multiple platforms and applications.Your tasksDesign, implement, and evolve COS REST APIs and event schemas (OpenAPI, API Gateway), enabling contract-first integrations and decoupling consumers from Order Management platform.Develop and orchestrate event-driven order workflows with Kafka/Kafka Streams and Temporal (basket-to-order, payment/checkout, digital activation, fulfillment, transport management), ensuring reliability, idem-potency, and auditability.Build and maintain data persistence and propagation: model order data in Protobuf, MongoDB, PostgreSQL, drive real-time synchronization to corporate systems, and support analytics via Pub/Sub to BigQuery with strong data quality and PII safeguards.Operate the platform on GCP/Kubernetes using GitOps (Flux): monitor and troubleshoot production, optimize performance and scalability, manage incidents, and continually improve SLAs,



security, and resilience.What will you need to fit in itStrong experience building event-driven, distributed systemsProficiency in Kotlin on the JVM; solid Java skills; familiarity with Python or TypeScript is a plus.Proven track record designing contract-first RESTful APIs with OpenAPI, including versioning, error models, and API gateway policies (e.g., Kong/Apigee).Practical experience with relational and noSQL databases (like MongoDB and PostgreSQL), schema design, transactions, performance tuning in high-throughput environments.Experience in cloud-native operations, e.g. on GCP with Kubernetes and Terraform; GitOps (Flux), CI/CD, observability (logging, metrics, tracing), and production troubleshooting.Integration expertise using synchronous and asynchronous patterns (Kafka, Google Pub/Sub, etc.) across enterprise systemsStrong focus on reliability, security, and compliance for customer order data (SLAs, auditability, PII/GDPR), with clear communication and cross-functional collaboration skills.What will you get in returnPermanent contract, directly with the final companyCompetitive gross salary in line with your experience (up to 50k)Adaptable working hoursOffices located in Barceloneta or El Prat de Llobregat, Barcelona4 work from home days per week27 days of vacation per yearTraining budget and language classesYoung and dynamic tech environment with strong collaboration cultureLong‑term professional development plan and exposure to cutting-edge technologiesYour next stepIf you’re interested in this opportunity, click “Apply now” to submit an updated copy of your CV, or give us a call.If this role isn’t quite right for you but you’re considering a new opportunity, please get in touch and we’d be happy to discuss your options. All conversations will be treated confidentially.#LI-DNI #1130785 - Anna Garriga

📌 Kotlin Backend SW Engineer (Barcelona)
🏢 Hays
📍 Barcelona