Senior Java Developer - Remote & Cloud-Native Microservices

Ust España & Latam; Tarragona; Presencial; EUR 70.000 - 110.000; Jornada completa

Ventajas ofrecidas por este puesto de trabajo

23 days annual leave

Discretionary days (Dec)

Health care plan

Internet connectivity

Life and accident insurances

Flexible compensation program

Training platforms

Career development plans

Referral bonuses

12 or 14 salary payments per year

Work-life balance and remote policy

UST Club discounts and gym

Descripción de la vacante

UST is seeking a Senior Java Developer to join our global engineering team. You will design, develop, and evolve mission-critical backend services using Java 17/21, Spring Boot, and cloud-native architectures.

You’ll build reactive microservices with gRPC APIs, work with Kafka, and contribute to testing, architecture decisions, and documentation. You will thrive in a distributed environment, participate in CI/CD, and help shape technical strategy across cross-functional teams.

Formación

• 8+ years of professional Java development experience.
• 3+ years with Java 17/21, including records, sealed classes, pattern matching, and virtual threads.
• Strong Spring Framework and Spring Boot production experience.
• Reactive programming with Project Reactor or RxJava, or async with CompletableFuture and structured concurrency.
• Production experience with gRPC and Protocol Buffers.
• Strong understanding of concurrency fundamentals, executors, and thread lifecycle management.
• Solid testing with JUnit 5, Mockito, and AssertJ.
• Experience with integration tests and contract/parity testing.
• Strong knowledge of Kafka consumer/producer semantics.
• Experience with Redis, PostgreSQL, or MongoDB.
• Cloud experience with AWS (S3, IAM, managed Kafka, container runtimes).
• Excellent written communication and English (C1 level or higher).

Responsabilidades

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

Conocimientos

Java development

Spring Framework

Reactive programming

gRPC

Protocol Buffers

Concurrency

JUnit 5

Mockito

AssertJ

Kafka

AWS

English (C1)

Herramientas

gRPC

Protocol Buffers

Redis

PostgreSQL

MongoDB

Descripción del empleo

UST is seeking a Senior Java Developer to join our global engineering team. You will design, develop, and evolve mission-critical backend services using Java 17/21, Spring Boot, and cloud-native architectures.

You’ll build reactive microservices with gRPC APIs, work with Kafka, and contribute to testing, architecture decisions, and documentation. You will thrive in a distributed environment, participate in CI/CD, and help shape technical strategy across cross-functional teams.