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Blue Code . Tech & Feel

Freelance Kotlin Developer - Spain

Blue Code . Tech & Feel
Spain · Contract · Mid-Senior

This is a remote position.

Blue Code Alicante is looking for a Freelance Kotlin Developer (remote from Spain is a must) to join a high-ownership engineering team building and evolving a distributed microservices backend on AWS. You'll work across a complex domain that includes route optimization, schedule ingestion, geo-routing and carrier data, all at real scale. You'll take full ownership of services from design to production, drive architectural decisions and proactively identify and fix problems before they become incidents.


Responsibilities:


  • Design, build and maintain JVM-based microservices (Java / Kotlin) running on AWS ECS, App Runner and Lambda
  • Work with a rich data layer: PostgreSQL, DynamoDB, RedShift, Redis and S3
  • Build event-driven integrations via RabbitMQ and SNS
  • Collaborate on API design across REST (API Gateway) and BFF patterns
  • Instrument services with OpenTelemetry, Tempo, Prometheus and Grafana
  • Ship via GitHub Actions CI/CD pipelines with Docker and ECR
  • Work with external integrations including Auth0, GraphHopper, PostHog and Sentry
  • Participate in architecture decisions and technical direction


Requirements

  • Minimum 6 years of professional backend development in Kotlin / Java
  • Solid understanding of distributed systems design, microservice patterns and event-driven architecture
  • Hands-on production experience with AWS (ECS, Lambda, S3, RDS or DynamoDB)
  • Experience with relational databases (PostgreSQL) and NoSQL (DynamoDB or similar)
  • Strong command of Docker and containerized deployments
  • Experience with CI/CD pipelines (we use GitHub Actions)
  • Clean code as a practice
  • Registered as a freelance in Spain is a must

Nice to have (but not required):

  • Experience with message brokers (RabbitMQ, SQS/SNS)
  • Familiarity with observability tooling (OpenTelemetry, Prometheus/Grafana stacks)
  • Background in logistics, routing, geospatial or supply chain domains
  • Experience integrating third-party APIs (auth providers, mapping/routing engines, analytics)


Benefits

  • Competitive daily or hourly rate, negotiable based on experience / skills
  • International and dynamic work setting
  • Remote work model from Spain
  • Freelance / Contract B2B basis

Key Skills

Ranked by relevance

kotlin aws microservices postgresql rabbitmq dynamodb docker cicd ecs prometheus nosql redis java jvm s3
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Spain

Strong city options with excellent lifestyle

Posted
May 14, 2026
Type
Contract
Level
Mid-Senior
Location
Spain
Company
Blue Code . Tech & Feel

Industries

IT Services IT Consulting

Categories

Information Technology

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