Kotlin Fullstack Software Engineer

October 17, 2026

Office

Senior

Barcelona

Keep in mind

Office-only work

Also worth knowing

English is required
C1 level

Description

One of Europe's leading consumer retailers is hiring a Senior Full Stack Engineer for its Platform team, which enables product teams to build and scale digital experiences. The role covers payments, transactions, checkout experiences and distributed systems across the full software lifecycle, from requirements to production. The stack centers on Kotlin backend services and React/TypeScript frontend applications on GCP.

Responsibilities

Design, develop, and maintain scalable backend services using Kotlin and modern software engineering practices
Build and evolve frontend applications using React, TypeScript, HTML5, and CSS3
Design and integrate resilient REST APIs and distributed microservices
Participate in architectural discussions and technical decision-making
Contribute to the company's cloud migration and modernization initiatives
Improve monitoring, observability, and operational excellence across services
Take ownership of services from development through production following DevOps principles
Collaborate closely with product, engineering, and platform teams
Support team growth through knowledge sharing, mentoring, and code reviews

Requirements

5+ years of professional experience working with Kotlin
Strong knowledge of React, TypeScript, JavaScript, HTML5, and CSS3
Solid backend development experience with Kotlin, Java, Spring Boot, Node.js, Express
Strong experience designing and integrating RESTful APIs
Experience building and maintaining microservices architectures
Experience with relational and NoSQL databases
Experience using Git and collaborative development workflows
Experience working with cloud platforms, preferably Google Cloud Platform (GCP)
Hands-on experience with CI/CD pipelines
Familiarity with Docker and Kubernetes
Strong understanding of software design principles, design patterns, testing strategies, and Clean Code practices
Professional-level English communication skills
Nice to have: experience integrating payment gateways such as Stripe or PayPal
Nice to have: GitOps tools such as Terraform, Helm, or Flux
Nice to have: observability tools like Grafana, Prometheus, Kibana
Nice to have: experience operating business-critical services in production
Nice to have: AI-assisted development tools such as GitHub Copilot or Claude Code
Nice to have: knowledge of web security best practices

Conditions

Permanent contract, directly with the final company
Competitive gross salary in line with your experience (up to 50k)
Flexible working hours
Offices located in Barceloneta or El Prat de Llobregat
27 days of vacation per year
Training budget and language classes
Long-term professional development plan and exposure to cutting-edge technologies
Full-time employment