About the role
Our client is a Barcelona-based product company that builds its own SaaS platform, used by thousands of businesses across Europe. Engineering is organised in small, autonomous product teams that own their services from design to production.
They are looking for a Senior Backend Engineer to join one of the core platform teams. You will design and build event-driven microservices, help evolve the architecture as the product scales, and set the technical bar for the team.
The stack is mainly Kotlin on the JVM with some Python services, running on AWS with Kubernetes, PostgreSQL and Kafka. This is a senior individual contributor role with real influence over technical decisions.
Responsibilities
- Design, build and run backend services in Kotlin (and some Python) that are reliable, observable and easy to change.
- Shape the architecture of an event-driven microservices platform, including service boundaries, APIs and data ownership.
- Work with Kafka, PostgreSQL and AWS managed services to build scalable data flows.
- Own your services in production: monitoring, alerting, on-call and incident follow-up.
- Improve performance, resilience and cost efficiency of existing services.
- Work closely with product managers and designers to turn product ideas into technical plans.
- Review code, mentor other engineers and promote good engineering practices.
- Contribute to technical design documents and engineering-wide decisions.
Requirements
- 6+ years of experience in backend development.
- Strong experience with Kotlin or Java (Spring Boot, Ktor or similar); Python is a plus.
- Experience designing and running microservices in production.
- Hands-on experience with AWS (or another major cloud) and Kubernetes.
- Experience with event-driven architectures and messaging (Kafka, SQS or similar).
- Strong SQL skills and experience with PostgreSQL or similar relational databases.
- Good testing habits: unit, integration and contract tests.
- Experience with CI/CD and infrastructure as code (Terraform or similar).
- Professional English; Spanish is not required.
Nice to have
- Experience in B2B SaaS or multi-tenant platforms.
- Knowledge of observability tools (OpenTelemetry, Datadog, Grafana).
- Experience with domain-driven design.
What we offer
- Competitive salary
- Hybrid model with flexible hours
- Private health insurance
- Flexible benefits (meal allowance, transport, childcare)
- Training budget and conference attendance
- Modern office in Barcelona