Senior Java Developer with strong AWS expertise $$$

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. 

As a Senior Java Developer with strong AWS expertise, you will join an exciting long‑term project for one of our clients, a leading global provider of technology solutions in the online trading domain. You will contribute directly to the development of a large‑scale Share Dealing application that enables UK‑based customers to securely access and trade on global financial markets.

This role involves designing and enhancing a high‑performance trading platform, building cloud‑native services, and ensuring the solution’s scalability, reliability, and seamless performance under real‑world trading loads.

Responsibilities:

• Participate in architectural and design review sessions, contributing to requirement analysis, technical discussions, and SCRUM ceremonies
• Design, develop, and optimize high‑performance Java and Spring‑based services for a mission‑critical online trading platform
• Build and enhance cloud‑native components using various AWS services (Lambda, ECS/EKS, SQS, API Gateway, DynamoDB, SNS, CloudWatch, EventBridge, IAM, Step Functions, Route53, ElastiCache)
• Implement best‑practice approaches for application performance, scalability, and security 
• Create and maintain technical documentation, validate solution architecture, and ensure consistency across services
• Integrate with internal and external systems (including Kafka‑based messaging and MS Entra identity services)
• Develop RESTful APIs and ensure reliability, high availability, and fault tolerance
• Support CI/CD processes using GitLab and Infrastructure‑as‑Code tools like Terraform and CloudFormation
• Collaborate closely with cross‑functional teams across Europe, providing guidance and mentoring where needed

Key Requirements:

• Minimum 6 years of experience with Java, including deep knowledge of Spring/Spring Boot
• Strong expertise with AWS cloud services (Lambda/ECS/EKS, SQS, DynamoDB, API Gateway, EventBridge, SNS, IAM, CloudWatch, etc.)
• Hands‑on experience with Terraform or CloudFormation
• Strong understanding of distributed systems, event‑driven architectures, microservices, and asynchronous communication
• Experience working with Kafka
• Confident in working with Typescript (nice to have but strongly preferred)
• Strong background in building scalable REST APIs
• Ability to work independently, proactively, and with an open‑mind approach to problem‑solving
• Excellent communication skills in English
• Tax residence in Ukraine is required

Our benefits:

• Language courses
• Training and Certification
• Mentorship program
• Referral program
• Corporate Volunteer Grant Programs
• And other interesting opportunities!