Mid/Senior Backend Engineer (Java)

Quick Facts

• Role: Mid/Senior Backend Engineer (Java)

• Focus: Payments orchestration and external provider integrations

• Contract: B2B

• Work model: Remote from Poland (initial workshops in Kraków and onsite follow-ups about once per quarter)

• Start: ASAP or agreed date

• Rate: 120–150 PLN/h + VAT (final rate depends on seniority, payments experience, and technical fit)

Description

West Code is building a new team for a greenfield international gaming platform. The Payments team will own payment orchestration and integrations with external payment providers, building backend services where reliability, transaction consistency, and failure handling matter as much as clean code.

Responsibilities

• Build payment orchestration services with Java 21+ and Spring Boot 3

• Implement provider/PSP integrations with a consistent integration layer

• Develop transaction flows (deposits, withdrawals, refunds, reversals) and status handling

• Create routing, retry, timeout, and fallback mechanisms

• Ensure idempotency and protect against duplicate events

• Handle asynchronous callbacks/webhooks and event-driven flows

• Perform reconciliation and maintain transaction-state consistency

• Deliver high-volume, highly available services with strong observability

Requirements

• 4+ years of backend engineering experience

• Strong Java and Spring Boot

• Experience with microservices and distributed systems

• Kafka or a similar messaging platform

• REST APIs and external system integrations

• SQL/PostgreSQL (or similar relational database) experience

• Docker and CI/CD

• Experience working with production systems

• Good English and ability to work independently

Benefits

• Greenfield delivery with direct access to senior technical leadership

• Opportunity to influence technical decisions and design implementation early

• International team with English used on the project

• AI-assisted engineering workflows supporting code quality, security, requirements context, and knowledge transfer