FX Senior Java Developer (f/m/x)

Sii is a company active in the financial sector working on modern backend systems for high-performance and scalable solutions. They build distributed environments focusing on processing large volumes of data and microservices architecture.

• Minimum 10 years in software development
• Very good knowledge of Java (backend) and Spring
• Strong understanding of REST APIs, HTTPS, microservices, and message queues (MQ)
• Ability to design high-availability, scalable, and high-performance systems
• Very good knowledge of relational databases (SQL)
• Familiarity with CI/CD pipelines and Agile ways of working
• Knowledge of distributed systems and data processing
• Hands-on work with Kubernetes and cloud platforms (GCP preferred)
• Fluent Polish and English required
• Residing in Poland required

Nice to have:

• Knowledge of Go, Rust, or similar system-level languages
• Experience with NoSQL and analytical databases, e.g., ClickHouse
• Frontend development experience
• Familiarity with the banking sector (trade lifecycle, FX, post-trade processing)
• Banking experience / FX experience (forex)
• Working from the office in Krakow 6 times per month

• Designing and developing backend systems based on Java
• Creating and evolving a microservices architecture
• Building and maintaining REST APIs and system integrations
• Designing solutions that meet high availability and performance requirements
• Working with systems that process large volumes of data
• Collaborating with the team using Agile methodologies
• Participating in architecture design and technical decision-making
• Implementing and optimizing CI/CD processes and ensuring system security

Residing in Poland required