More in detail, UST is a multinational company based in North America, certified as a Top Employer and Great Place to Work company with over 35,000 employees worldwide and presence in more than 35 countries. We are leaders in digital technology services, providing large-scale technological solutions to some of the world's most renowned organizations.

We are seeking a highly skilled Senior Java Developer with extensive experience building scalable, high-performance distributed systems.
You will join a talented engineering team responsible for designing, developing, and evolving mission-critical applications using modern Java, cloud-native architectures, and event-driven technologies.

⚙ Design, develop, and maintain robust backend services using Java 17/21 and Spring Boot.
Develop and maintain gRPC APIs and Protobuf schemas, ensuring backward compatibility and proper schema evolution.
Work with Kafka-based event-driven architectures and production-scale data stores.
Create and maintain automated testing suites, including unit, integration, and contract tests.
Participate in troubleshooting, root cause analysis, and postmortem activities.
Contribute to CI/CD pipelines, cloud infrastructure, and containerized deployments.
8+ years of professional experience with Java development.
~3+ years of hands-on experience with Java 17 or Java 21, including modern language features such as records, sealed classes, pattern matching,



and virtual threads when applicable.
~ Strong expertise in Spring Framework and Spring Boot in production environments.
~ Proven experience with reactive programming using Project Reactor or RxJava (Mono, Flux, backpressure, retry strategies, hot vs. Solid testing practices using JUnit 5, Mockito, and AssertJ.
~ Experience developing integration tests against real dependencies and contract/parity testing.
~ Strong knowledge of Kafka consumer and producer semantics.
~ Redis, PostgreSQL, or MongoDB.
~ Cloud experience with AWS (or equivalent cloud platforms), including services such as S3, IAM, managed Kafka solutions, and container runtimes.
~ English level C1 or higher.

Knowledge of container packaging and multi-architecture image builds (Linux/AMD64 and Linux/ARM64).
Python knowledge with the ability to read, understand, and debug existing code.
Experience working with Apache Arrow or other columnar data formats.
CI/CD pipeline ownership using TeamCity, GitHub Actions, or similar technologies.
Numerous benefits (Health Care Plan, Internet Connectivity, Life and Accident Insurances).
~ Adaptable Compensation Program: meals, kindergarten, transport, online English lessons, health care plan, and more.
~ Free access to several training platforms.
~ Real Work-Life Balance measures (flexibility, remote work policy, summer schedule, and more).
~

📌 Senior Java Developer (AWS/RxJava) (Marzán)
🏢 UST España & Latam
📍 Marzán