Senior Java Developer

We are still looking for the very Top Talent...and we would be delighted if you were to join our team

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.

What we look for?

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.

⚙ Key Responsibilities:

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

Mandatory Requirements:

• 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. cold publishers), or advanced asynchronous programming with CompletableFuture and structured concurrency.
• Production experience with gRPC and Protocol Buffers, including streaming RPCs, deadlines, interceptors, and schema evolution.
• Strong understanding of concurrency fundamentals, executor services, lock-free patterns, and thread lifecycle management.
• 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.
• Production experience with at least one of the following technologies: Redis, PostgreSQL, or MongoDB.
• Cloud experience with AWS (or equivalent cloud platforms), including services such as S3, IAM, managed Kafka solutions, and container runtimes.
• Excellent written communication skills with the ability to create design documents, postmortems, and technical documentation.
• English level C1 or higher.

Nice to Have:

• Experience leading large-scale migrations or refactoring initiatives across multi-module codebases.
• 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.
• Experience contributing to architecture and technical strategy discussions.

What can we offer?

• 23 days of Annual Leave plus the 24th and 31st of December as discretionary days
• Numerous benefits (Health Care Plan, Internet Connectivity, Life and Accident Insurances).
• Flexible Compensation Program: meals, kindergarten, transport, online English lessons, health care plan, and more.
• Free access to several training platforms.
• Professional stability and personalized career development plans.
• Referral Program with attractive bonuses for successful recommendations.
• The option to choose between 12 or 14 salary payments per year.
• Real Work-Life Balance measures (flexibility, remote work policy, summer schedule, and more).
• Access to UST Club discounts and gym membership benefits.

If you would like to know more, do not hesitate to apply and we'll get