10/03/2026 updated
100 % available
Senior Java/Kotlin Software Engineer
San Antonio de Benageber, Spain
Only remote
Master's degree, EconomicsAbout me
Senior Java/Kotlin Engineer with strong experience in Spring Boot, AWS, Kafka and distributed systems. I build high-load backend platforms, work across architecture, implementation and production, and am available for remote B2B contracts across Europe.
GCPAzure DevOpsJava (Programming Language)Spring SecurityApplication Programming Interfaces (APIs)GitHubJava Development ToolsSpring FrameworkPostgreSQLMySQLSystems IntegrationSnowflakeSpring BootBackendAWS ECS
Java & Kotlin Development
10+ years of experience in backend software development with Java and Kotlin, primarily using Spring Boot. Strong experience building scalable, distributed and event-driven systems in enterprise environments.
Distributed Systems & High-Load Platforms
Experience designing and developing backend services processing very large volumes of data, including telemetry platforms handling around 100M events per day with significantly higher peak loads. Strong focus on scalability, reliability and performance.
Microservices & Cloud Architecture
Design and implementation of microservice architectures on AWS using services such as ECS, EKS, Kinesis, S3, RDS, DynamoDB, Athena and CloudWatch. Experience working with Docker, Kubernetes and cloud infrastructure as part of the full development lifecycle.
Messaging & Event-Driven Architecture
Hands-on experience with Apache Kafka and AWS Kinesis for asynchronous communication, event streaming and high-throughput data processing. Experience designing reliable event-driven workflows and integrating distributed services.
API Design & Backend Services
Design and implementation of REST APIs and backend services using Java, Kotlin and Spring Boot. Experience working from architecture and requirements through implementation, testing, deployment and production support.
Databases & Data Platforms
Experience with PostgreSQL, MySQL, DynamoDB, Redis, Snowflake and OpenSearch. Strong SQL knowledge, database performance analysis, indexing and query optimization for large datasets.
Testing & Software Quality
Experience with unit, integration and end-to-end testing using JUnit, Mockito, WireMock and Testcontainers. Strong focus on maintainability, regression safety and production reliability.
DevOps & CI/CD
Experience with CI/CD using Azure DevOps and GitHub Actions, as well as infrastructure and deployment workflows across AWS, Docker and Kubernetes environments.
Technical Ownership
End-to-end ownership of backend services and APIs, including architecture discussions, technical design, implementation, testing, infrastructure, deployment and production support. Regular collaboration with architects, product owners, QA engineers and other development teams.
Agile Development
Extensive experience working in Scrum-based teams, participating in planning, refinement, reviews, retrospectives and technical decision-making.
Experience
Professional experience10+ years
Freelancer since2012
Languages
EnglishFluent
Project history
Leitung der Backend-Entwicklung fuer S.O.S Services im Helios-Programm. Verantwortung fuer Anforderungsanalyse, API-Design, Implementierung und Release-Koordination fuer drei Core-APIs. Entwicklung des Dealer Mapping Service, des Grief Notification Service und des Grief Resolution Service. Koordination mit Product Ownern, Solution Architects, QA und UI-Engineers. Technologien: Java 21, Kotlin, Spring Boot 3, AWS (Kinesis, MSK, S3, Athena, CloudFormation, CloudWatch, DynamoDB, OpenSearch, RDS, EC2, EKS, Lambda), MySQL, PostgreSQL, Apache Kafka, Azure, JOOQ.
Entwicklung und Optimierung einer hochlastigen Streaming-Plattform (VisionLink) mit mehr als 100 Millionen Events taeglich. Entwurf und Wartung eines Onboarding-Service mit 500+ RPS. Implementierung fehlertoleranter Datenverarbeitung fuer Kinesis-Streams mit S3-Backup. Optimierung von Datenbankabfragen von 4000ms auf 20-40ms. Technologien: Java 21, Kotlin, Spring Boot 3, AWS, MySQL, PostgreSQL, Apache Kafka, Azure, JOOQ.
Arbeit an einer hochperformanten globalen E-Commerce-Plattform (TVH) mit Java 17 und Spring WebFlux. Implementierung neuer Features, RESTful APIs und Integrationen. Anwendung von TDD, CI/CD, verteiltem Logging und Monitoring. Technologien: Java 17, Spring Boot 3, Spring WebFlux, Redis, GCP, PostgreSQL, JUnit, Mockito, Testcontainers, Apache Kafka, Git, Gitlab, Docker, Jenkins, ELK, Grafana, Argo CD.