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 deg 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!