Your New Company

One of Europe's leading consumer retailers is looking to hire a Backend Software Engineer to join one of the squads.

Your New Role

- Develop 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 tasks

- Design, 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 it
- Strong experience building event-driven, distributed systems
- Proficiency 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 systems
- Strong 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 return

- Permanent contract, directly with the final company
- Competitive gross salary in line with your experience (up to 50k)
- Versátil working hours
- Offices located in Barceloneta or El Prat de Llobregat, Barcelona
- 4 work from home days per week
- 27 days of vacation per year
- Training budget and language classes
- Young and dynamic tech environment with strong collaboration culture
- Long-term professional development plan and exposure to cutting-edge technologies

Your next step

If 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