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# Senior Kotlin Fullstack Developer

- **Company:** Hays
- **Location:** Barcelona, Spain
- **Salary:** €45,000.0
- **Contract:** Permanent contract
- **Skills:** Clean Code Principles, Architectural Patterns, Cloud Computing, Software Design Patterns, DevOps, Distributed Systems, Monitoring of Systems, PostgreSQL, MongoDB, MySQL, Software Architecture, Prometheus, Strategies of Testing, Google Cloud, Cloud Platform System, Grafana, Spring-boot, Backend, Git, Kotlin, Kubernetes, Deployment Automation, Kibana, Restful APIs, Terraform, Serverless Computing, Microservices
- **Published:** October 27, 2026
- **Apply:** https://www.hays.es/detalles-vacante/senior-kotlin-fullstack-developer-barcelona_1130306

## About the Role

* 5+ years of professional experience working with Kotlin.
 * Strong backend development experience with technologies and frameworks such as:
 + Kotlin
 + Spring Boot (highly valued)
 + Quarkus (highly valued)

 * Experience designing, developing, and maintaining RESTful APIs.
 * Strong understanding of microservices architecture and distributed systems.
 * Experience working with:
 + PostgreSQL
 + MySQL
 + MongoDB
 * Experience using Git and collaborative development workflows.
 * Experience working with cloud platforms, preferably Google Cloud Platform (GCP).
 * Experience with CI/CD pipelines and deployment automation.
 * Experience with Kubernetes and GitOps tools such as Terraform, Helm, or Flux.
 * Familiarity with monitoring and observability tools such as Grafana, Prometheus, and Kibana.
 * Strong understanding of software design patterns, testing strategies, and Clean Code principles.
 * Excellent written and spoken English communication skills.

## Description

You will join a fast-growing international technology company where software is at the core of the company and engineering excellence is a key driver of success.
You will become part of a highly skilled team responsible for core platform services that support critical business operations. The company is heavily investing in modern architectures, cloud technologies, DevOps practices, and scalable systems to support long-term growth.
This is an environment where ownership, collaboration, innovation, and continuous improvement are highly valued., As a Senior Backend Engineer, you will join a team responsible for maintaining and evolving a business-critical platform focused on transactional services and platform capabilities.
You will work closely with other engineers to design, build, and maintain scalable backend services while contributing to architectural decisions and platform modernization initiatives.
Your responsibilities will include:

 * Designing and developing robust backend services using Kotlin.
 * Building and maintaining scalable REST APIs and distributed microservices.
 * Participating in architectural discussions focused on scalability, performance, and maintainability.
 * Contributing to the migration and modernization of cloud-native services.
 * Improving reliability, observability, and operational excellence across the platform.
 * Managing services following a DevOps mindset, from requirements analysis through production operation.
 * Identifying recurring operational issues and implementing automated solutions.
 * Collaborating with engineering teams to share knowledge and improve development practices.
 * Supporting the adoption of modern engineering standards, testing strategies, and platform tooling.