Senior Java Engineer - AWS & Reactive Microservices

UST; Madrid; Presencial; EUR 70.000 - 110.000; Jornada completa

Ventajas ofrecidas por este puesto de trabajo

Annual leave + discretionary days (Dec

Health & life insurances

Flexible compensation program

Free access to training platforms

Career development plans

Referral bonuses

12 or 14 salary payments

Work-Life Balance measures

UST Club discounts & gym

Descripción de la vacante

UST is seeking a Senior Java Developer to design, develop, and evolve mission-critical applications using Java 17/21, Spring Boot, and cloud-native architectures. You will work on scalable microservices, reactive programming, and gRPC with a focus on performance and scalability.

The role requires strong Java expertise, production experience with Spring and Kafka, and cloud usage (AWS). Excellent communication and English (C1) are essential.

Formación

• 8+ years of professional Java development experience.
• 3+ years with Java 17 or 21 (records, sealed classes, pattern matching, virtual threads).
• Strong expertise in Spring Framework and Spring Boot in production environments.
• Experience with reactive programming (Project Reactor or RxJava) or advanced asynchronous programming with CompletableFuture.
• Production experience with gRPC and Protocol Buffers, incl. streaming RPCs and schema evolution.
• Strong understanding of concurrency fundamentals and thread management.
• Solid testing practices with JUnit 5, Mockito, and AssertJ.
• Experience with integration tests and contract/parity testing.
• Strong knowledge of Kafka consumer/producer semantics and cloud services (AWS).

Responsabilidades

• Design, develop, and maintain backend services using Java 17/21 and Spring Boot.
• Build scalable microservices with reactive programming principles.
• Develop and maintain gRPC APIs and Protobuf schemas with backward compatibility.
• Implement highly concurrent and performant solutions with proper concurrency patterns.
• Work with Kafka-based event-driven architectures and production data stores.
• Create and maintain automated tests (unit/integration/contract).
• Collaborate with cross-functional teams on architecture decisions and docs.
• Participate in troubleshooting, root cause analysis, and postmortems.
• Contribute to CI/CD pipelines, cloud infrastructure, and container deployments.
• Produce design documents and PR descriptions.

Conocimientos

Java

CI/CD

Amazon S3

AWS

JUnit

Spring

PostgreSQL

MongoDB

Python

Contract Testing

Docker

Descripción del empleo

UST is seeking a Senior Java Developer to design, develop, and evolve mission-critical applications using Java 17/21, Spring Boot, and cloud-native architectures. You will work on scalable microservices, reactive programming, and gRPC with a focus on performance and scalability.

The role requires strong Java expertise, production experience with Spring and Kafka, and cloud usage (AWS). Excellent communication and English (C1) are essential.