FIX 4.4 Integration Engineer

About the role

Capco Poland is looking for a Poland-based Senior Integration & Workflow Engineer to design and develop custom middleware and workflow-orchestration components that connect capital markets platforms, blockchain infrastructure and market infrastructure. The role covers pre-trade validation, transaction orchestration, settlement processing and downstream system integration, and is offered under a flexible B2B collaboration model.

Key responsibilities

• Design and develop custom middleware and workflow-orchestration services, including REST/API integrations with internal and third-party platforms
• Build FIX 4.4 message flows and routing logic between the exchange environment and DLT/tokenized order flows, with message mapping, validation, acknowledgements, execution reports and error handling
• Implement transaction and workflow state management, validation, routing, reservation/earmark and transaction-processing logic
• Develop adapters and integration services for external platforms and market-infrastructure systems
• Implement idempotency, retry, queueing, replay and recovery patterns, and asynchronous/event-driven processing where required
• Build exception handling, audit logging, monitoring and traceability, and support authentication, authorization and API security
• Develop data mappings, transformation and canonical integration models, and automated unit and component tests
• Troubleshoot cross-system integration and production issues, support CI/CD and deployment, and produce technical documentation

Required profile

• Strong hands-on experience developing enterprise integration and middleware applications
• Strong FIX 4.4 experience, including message structures, tags, session management, routing and execution reporting
• Experience integrating FIX 4.4 exchange order flows with API/middleware-based downstream systems, including DLT or other non-traditional market infrastructure
• Experience with workflow/orchestration or transaction-processing applications and with asynchronous, event-driven patterns
• Experience with relational databases, third-party vendor APIs, secure enterprise development and Git/CI/CD
• Financial services integration experience, especially capital markets, payments, trading or settlement, and exposure to blockchain/DLT, digital assets or custody platforms is preferred

Required skills

• FIX 4.4, REST API and service integration
• Java / Spring Boot.NET/C# or Node.js/TypeScript
• Kafka, MQ or equivalent messaging
• Distributed-system patterns: idempotency, retries, timeouts, circuit breakers, concurrency and failure recovery

The process involves an HR interview, a technical interview, a client interview, feedback and an offer. The position is listed as hybrid (#LI-HYBRID).