Java Developer for a Fintect Project (b2b, Poland-based)

S* S* Inc

S* S* Science Inc is a U.S.-based fintech company operating in the investment and financial services space. Our distributed teams work across Poland, the United States, and Ireland, collaborating on technology-driven solutions related to stocks and investments.

Security, compliance, and the responsible handling of sensitive financial data are central to how we operate as we build scalable products in a regulated environment.

Project

The engineer will initially get familiar with the product, domain, and existing codebase by working on current issues and fixes. After onboarding, the role will gradually expand into the development of new change requests and product enhancements.

The project is focused on backend development within a complex fintech environment involving distributed systems, microservices, event-driven architecture, cloud technologies, and data-intensive applications.

Requirements

We are looking for an experienced backend engineer with strong hands-on experience in:

• Core Java and Spring
• Server-side development
• SQL
• Microservices
• REST APIs
• Kafka and event-driven architectures
• Python
• Kubernetes
• GitHub
• Redis and caching
• Azure
• Snowflake
• PostgreSQL
• Cloud-native development
• CI/CD
• Distributed systems
• Concurrency
• Multi-tenancy
• Data governance

Experience with modern LLM and agentic technologies is highly valuable, including:

• Prompt engineering
• Model Context Protocol (MCP)
• Retrieval-Augmented Generation (RAG)
• LLM/agentic development

Engagement Details

Initial contract duration: 1 year, with the possibility of extension based on performance and skill set
Hourly remuneration: $32.5 USD/hour for a Middle engineer – 35 USD/hour  for a Senior Engineer 
Engagement: Full-time
Location / time zone: Poland
Working language: English
Working hours: Standard Polish working hours, with at least 4 hours of overlap with U.S. Eastern Time

Recruitment Process

The recruitment process follows our standard interview stages, including technical and client-side evaluation.

Important — Please Read Before Applying

The client is building a product in the banking, investment, and brokerage systems domain. Due to strict investor, security, and compliance requirements, every candidate must successfully complete a background check.

For this reason, candidates must:

• be currently based in Poland;
• have been a taxpayer in Poland for at least 2 years;
• be able to provide the required documentation for the background-check process.

We are looking for someone who can quickly understand an existing system, resolve complex backend issues, and gradually take ownership of new development in a security-sensitive fintech environment.