05/26/2026 updated
JP
100 % available
Senior Backend Engineer | Java & Kotlin | Spring Boot | Kafka | AWS | B2B Contractor
MADRID, Spain
Only remote
B.Sc. in Software EngineeringAbout me
Backend engineer with 7+ years building production distributed systems for Iberia, KPN, Mercadona, Inditex, Openbank, and Idealista. Java & Kotlin on Spring Boot, Kafka, PostgreSQL, and AWS. Hexagonal architecture, DDD, and TDD as daily practice. B2B contractor, available remote or Madrid.
DDDJava (Programming Language)Amazon Web ServicesMicrosoft AzureCommand-Query Responsibility Segregation (Software Development)Amazon DynamoDBElasticsearchJUnitPostgreSQLMongoDBRedisGoogle CloudSpring BootBackendGit
Java & Kotlin Backend Development
Extensive experience building production-grade distributed systems using Java and Kotlin on Spring Boot, covering REST APIs, Spring Batch pipelines, and serverless architectures across multiple large-scale enterprise projects.
Cloud & AWS Architecture
Deep hands-on expertise with AWS services including Lambda, ECS, SQS, S3, and DynamoDB, as well as GCP and Azure, delivering high-concurrency and serverless environments for clients such as Inditex, Openbank, and Mercadona.
Hexagonal Architecture, DDD & TDD
Consistent application of hexagonal architecture, Domain-Driven Design, and Test-Driven Development as daily engineering practices, achieving high automated test coverage with JUnit, MockK, and Karate across multiple production systems.
Apache Kafka & Event-Driven Systems
Design and implementation of event-driven microservices using Kafka for real-time event streaming, event sourcing patterns, and high-throughput messaging across distributed systems.
PostgreSQL & Database Management
Proficient use of PostgreSQL as a primary relational database, including schema migrations with Flyway and Liquibase, as well as experience with MongoDB, Elasticsearch, Redis, and DynamoDB.
Docker & Kubernetes
Containerisation of services using Docker and orchestration with Kubernetes, supporting zero-downtime deployments and scalable infrastructure across cloud environments.
CQRS & Event Sourcing
Application of CQRS and Event Sourcing patterns to maintain full audit trails and decouple read and write models in complex domain-driven systems.
Infra & DevOps Tooling
Experience with Jenkins, Prometheus, Grafana, and Git for CI/CD pipelines, monitoring, and version control in professional engineering environments.
Vue.js & React
Occasional frontend contributions using Vue.js and React to keep UI components aligned with backend data models and support full-stack feature delivery.
Extensive experience building production-grade distributed systems using Java and Kotlin on Spring Boot, covering REST APIs, Spring Batch pipelines, and serverless architectures across multiple large-scale enterprise projects.
Cloud & AWS Architecture
Deep hands-on expertise with AWS services including Lambda, ECS, SQS, S3, and DynamoDB, as well as GCP and Azure, delivering high-concurrency and serverless environments for clients such as Inditex, Openbank, and Mercadona.
Hexagonal Architecture, DDD & TDD
Consistent application of hexagonal architecture, Domain-Driven Design, and Test-Driven Development as daily engineering practices, achieving high automated test coverage with JUnit, MockK, and Karate across multiple production systems.
Apache Kafka & Event-Driven Systems
Design and implementation of event-driven microservices using Kafka for real-time event streaming, event sourcing patterns, and high-throughput messaging across distributed systems.
PostgreSQL & Database Management
Proficient use of PostgreSQL as a primary relational database, including schema migrations with Flyway and Liquibase, as well as experience with MongoDB, Elasticsearch, Redis, and DynamoDB.
Docker & Kubernetes
Containerisation of services using Docker and orchestration with Kubernetes, supporting zero-downtime deployments and scalable infrastructure across cloud environments.
CQRS & Event Sourcing
Application of CQRS and Event Sourcing patterns to maintain full audit trails and decouple read and write models in complex domain-driven systems.
Infra & DevOps Tooling
Experience with Jenkins, Prometheus, Grafana, and Git for CI/CD pipelines, monitoring, and version control in professional engineering environments.
Vue.js & React
Occasional frontend contributions using Vue.js and React to keep UI components aligned with backend data models and support full-stack feature delivery.
Languages
EnglishGoodSpanishNative speaker
Project history
Booking and ticketing microservices on Iberia's flight reservation platform. REST services consumed by internal channels and third-party GDS/NDC distribution partners under IATA compliance. Redis caching strategies on highest-traffic booking flows. Service design in hexagonal architecture with DDD; integrations over Kafka and PostgreSQL on AWS (ECS, SQS, S3). Stack: Java, Spring Boot, Redis, Kafka, PostgreSQL, AWS.
Used-car search engine aggregating major Spanish marketplaces into a single searchable index. Nightly web-scraping pipelines processing 100,000+ vehicle listings. Elasticsearch indexes optimised for sub-second full-text search. Containerised services on AWS with Docker refreshed by nightly cron jobs. Stack: Kotlin, Spring Boot, Elasticsearch, Docker, AWS, Gradle.
NFC-based time-attendance terminal with custom PCB hardware and companion mobile app. Designed and manufactured the PCB: ESP32-C6 microcontroller, PN532 NFC reader, PoE power supply. Firmware in C (ESP-IDF), backend in Spring Boot, mobile app in React Native. Stack: Java, Spring Boot, C (ESP-IDF), ESP32-C6, PN532, PostgreSQL, Docker, React Native.