Java Developer

Sii Ukraine is a subsidiary of Sii Poland — the leader in IT, engineering, and consultancy services with over 7500 IT experts in Poland and more than 250 prestigious customers. We are looking for ambitious and top-quality professionals to join our project teams.

We are looking for a Java Developer to join an exciting long-term project for one of our clients, a leading global provider of technology solutions in the online trading domain. The main focus of the project is the development and enhancement of Price Alerts functionality, enabling users to receive real-time notifications when financial instruments reach predefined price levels.

The role involves working on a high-performance, distributed system that integrates APIs, real-time market data, and frontend applications within a unified platform. You will work on well-defined tasks with a high level of ownership, contributing to a reliable and scalable solution in a dynamic, high-traffic environment.

Responsibilities:

• Develop and maintain backend services supporting Price Alerts functionality
• Implement solutions based on defined requirements, ensuring code quality and maintainability
• Build and enhance APIs and support service integrations
• Work with data storage, caching, and data migration mechanisms
• Support asynchronous communication and messaging between system components
• Write and maintain unit and integration tests to ensure application quality
• Participate in code reviews and follow best engineering practices

Key Requirements:

• 3+ years of commercial experience as a Java Developer
• Experience with Java 17+ and Spring Boot 3.x
• Ability to work independently on well-defined tasks
• Experience writing tests using JUnit 5 and Mockito
• Hands-on experience with caching mechanisms (e.g., Caffeine)
• Experience working with relational databases (PostgreSQL) and database migrations (Flyway)
• Basic understanding of messaging systems (AMQ)
• Understanding of REST APIs, microservices, and backend development principles
• Strong problem-solving skills and attention to detail
• Ability to work effectively in a team environment
• Fluency in English
• Tax residence in Ukraine is required