System Designer

Onwelo is a technology partner providing comprehensive services from strategy and architecture through implementation to maintenance in digital transformation, data, and automation. The team consists of over 400 specialists with senior competencies and has completed 300+ projects for large organizations in Poland, Europe, and the USA. Operations are based in several Polish cities and offices in Germany, Switzerland, and the USA, combining local presence with global reach.

• Minimum 5 years of experience in system design working with backend applications based on Java (Spring)
• Daily work with Confluence for creating and maintaining technical documentation, diagrams, and specifications
• Experience with Jira for backlog management, user stories, and Scrum
• Use of analytical BPMN tools (Camunda Modeler / Signavio), Draw.io / Miro / Figma, Postman / Swagger / Stoplight for API specification, Enterprise Architect / UML tools
• Design and document API contracts (REST / GraphQL) and system integrations
• Model systems and business processes using UML (sequence, component diagrams), BPMN, and ERD data models
• Knowledge of distributed system design principles (microservices, event-driven approach)
• Ability to read and analyze JavaScript / TypeScript and React code
• Experience with relational and non-relational databases
• English language proficiency at minimum B2 level

Nice to have:

• Advanced skills in Postman, Jira, Swagger, Figma, Confluence, Miro, BPMN

• Translate business requirements into detailed functional and technical specifications
• Design system logic, data flow, integration, and module architecture
• Create system diagrams, data models, API specifications, and technical user journeys
• Collaborate with IT architects on solution design
• Prepare technical documentation and update Confluence
• Co-create user stories and acceptance criteria in Jira
• Conduct consultations during internal tests and UAT