Technical Business Analyst – API and Middleware

Kraków | Full-time | Hybrid (4 days in the office @ Mogilska 35) | Permanent contract | Competitive salary + great benefits

Join StoneX – Where Technology Powers Global Finance

At StoneX, we’re not just connecting systems – we’re shaping how financial data moves securely and efficiently across the globe. As a Fortune 100, Nasdaq-listed fintech leader, we serve over 400,000 retail and institutional clients from 80+ offices on 5 continents.

We’re on a mission to build world-class products with meaningful impact. And we want passionate business analysts like you who can help us drive it.

Why Join Us?

• Opportunity to work on mission-critical systems in global trading
• Be part of a culture that values ownership, quality, and innovation
• Enjoy flexibility with hybrid work and private on-site parking
• Modern office in central Kraków: ul. Mogilska 35
• Access to personal development, career growth, and real impact

Ready to Apply?

Let’s build something meaningful together. Apply now and take your tech career to the next level.

About the Role

We’re looking for a Technical Business Analyst who can help drive our strategic API initiative. You’ll collaborate with engineering, architecture, and product teams to design, define, and deliver APIs that form the backbone of StoneX’s global connectivity.

If you thrive at the intersection of business and technology – translating complex integration needs into clear, scalable API solutions – this role is for you.

Key Responsibilities:

• Requirements Gathering & Analysis:
• Collaborate with Product Owners, Architects, Developers, and QA teams, to elicit and document clear, comprehensive business and technical requirements for APIs and middleware services.
• Translate integration needs from multiple systems into cohesive API specifications and reusable service definitions.
• Conduct gap analyses across existing APIs to identify areas for consolidation, standardization, or modernization.
• Technical Analysis & Troubleshooting:
• Analyze data flows, payloads, and service interactions to diagnose issues and recommend solutions.
• Collaborate with engineering teams to resolve technical challenges related to API integrations, caching, or data enrichment.
• Evaluate and recommend best practices in API design, versioning, and governance.
• Documentation & Modelling:
• Create and maintain detailed documentation including API contracts, data models, and process flows.
• Develop and maintain documentation supporting public and partner-facing APIs, ensuring clarity, security, and ease of adoption.
• Prepare training and onboarding materials for internal users and API consumers as needed.
• Agile Development Collaboration:
• Participate actively in Agile ceremonies including sprint planning, stand-ups, and backlog refinement.
• Partner with Product Owners to maintain and prioritize API development backlogs, balancing new capabilities, stability, and technical debt.
• Support the definition of API lifecycle processes–discovery, onboarding, change management, and deprecation.
• Integration & Testing Support:
• Define and validate integration points across internal systems and external partner channels.
• Support QA teams in designing test scenarios for API validation, contract testing, and performance benchmarking.
• Facilitate UAT and API consumer testing, ensuring alignment with business requirements and developer experience standards.
• Continuous Improvement:
• Identify opportunities to improve API reusability, performance, and developer experience.
• Contribute to defining API governance frameworks and standards for documentation, security, and version control.
• Provide insights into emerging API technologies, middleware tools, and architectural patterns such as event-driven design and microservices.

Qualifications:

• 5+ years of Business Analyst experience in a technology or integration-focused environment (API, middleware, data services).
• Strong understanding of API design principles (REST, gRPC, event streaming), data mapping, service-oriented architecture, and data analysis (eg, SQL).
• Proficiency in Agile methodologies (Scrum, Kanban) and cross-functional team collaboration.
• Hands-on experience with tools such as Swagger/OpenAPI, Postman, JIRA, Confluence, or Azure DevOps.

• Excellent analytical, communication, and documentation abilities.

• Ability to produce clear and detailed documentation, including user stories, process flows, and technical specifications.
• Preferred: experience defining public or partner-facing APIs, API gateways, and developer portals.

What makes you stand out

• Prior hands-on experience in technical roles such as software development or software testing

Education

• Bachelor's degree in Computer Science, Finance, Business, or a related field; or a combination of education and/or equivalent experience.