Senior QA Engineer - .NET / Test Automation

Billennium; Warszawa; On-site; PLN 140,000 - 210,000; Full time

Benefits offered by this job

Comprehensive benefits

Career growth

Innovative environment

Engaging community

Team-building events

A pleasant surprise

Job summary

Billennium in Poland is seeking a Senior QA Engineer to join a greenfield project building a core component of a new ecosystem supporting debt servicing and receivables management. You will design test scenarios, validate distributed services and REST APIs, implement automated UI/API/e2E tests using C#/.NET, Cypress or Playwright, and contribute to CI/CD pipelines with GitLab or GitHub Actions.

The role operates in an Agile Kanban environment with close collaboration with Developers and Product

Qualifications

• 4-5+ years of professional experience as a Tester / QA Engineer, including 2+ years in a Senior QA role.
• Strong experience in test automation covering UI, API and/or end-to-end testing.
• Hands-on experience testing distributed systems and service integrations.
• Practical experience with REST API testing.
• Experience with asynchronous communication and event-driven architectures, including queues and messaging.
• Experience creating and maintaining functional, regression and integration tests.
• Practical experience with C# and .NET.
• Knowledge of xUnit, Reqnroll and Shouldly.
• Experience with Cypress and/or Playwright.
• Experience with Testcontainers.
• Experience using Postman and/or Apidog.
• Hands-on experience with GitLab CI/CD and/or GitHub Actions.
• Good knowledge of Git, including branches and merge requests.
• Experience with Jira and Xray for test management, reporting and traceability.
• Practical SQL skills and experience with PostgreSQL.
• Experience working in Agile environments, preferably with Kanban.
• Experience following Domain-Driven Design (DDD) principles.

Responsibilities

• Design, create and maintain test scenarios and test cases covering functional, regression, integration and UAT testing.
• Test distributed systems and integrations between services.
• Test REST APIs and systems based on asynchronous and event-driven communication, including messaging and queues.
• Design, implement and maintain automated UI, API and end-to-end tests.
• Work with C# and .NET, using tools and frameworks such as xUnit, Reqnroll and Shouldly.
• Develop automated tests using Cypress and/or Playwright.
• Use Testcontainers and tools such as Postman or Apidog for API and integration testing.
• Integrate automated tests into CI/CD pipelines, including GitLab CI/CD and GitHub Actions.
• Work with Git, including branching strategies and merge requests.
• Manage testing activities, reporting and traceability using Jira and Xray.
• Use Grafana dashboards and alerts to monitor key quality and system indicators.
• Work with SQL and PostgreSQL to validate data and support testing activities.
• Collaborate closely with Developers and Product Owners to clarify requirements and identify potential quality risks early.
• Contribute to establishing and improving QA standards, testing practices and automation strategies.
• Share knowledge and support less experienced QA team members.
• Leverage AI-powered tools, such as Copilot and LLMs, to improve QA processes, automation and everyday productivity.

Skills

Test automation

REST API testing

Distributed systems testing

C# and .NET

CI/CD pipelines

Git

Jira Xray

SQL PostgreSQL

Agile Kanban

DDD

Tools

xUnit

Reqnroll

Shouldly

Job description

Billennium is a global technology company with over 20 years of experience, committed to innovation and empowering businesses. As an employer, we offer a supportive, growth-focused environment where collaboration and creativity thrive.

Join us to shape the future of technology together.

Role Summary:

We are looking for a Senior QA Engineer to join a greenfield project focused on building and evolving a core component of a new ecosystem supporting the debt servicing and receivables management processes.

The solution is designed around Domain-Driven Design (DDD) and consists of several autonomous Bounded Contexts covering both non-financial and financial areas, including Client Management, Party Management, Debt Management, Asset Management, Finance Engine, Payment Management and Collection Accounting.

The MVP has already been successfully deployed to production, and the team is now focused on delivering new functionalities, improving existing solutions and ensuring high quality across a distributed, event-driven architecture.

You will work closely with Developers and Product Owners in an Agile environment using Kanban.

What You Will Do:

• Design, create and maintain test scenarios and test cases covering functional, regression, integration and UAT testing.
• Test distributed systems and integrations between services.
• Test REST APIs and systems based on asynchronous and event-driven communication, including messaging and queues.
• Design, implement and maintain automated UI, API and end-to-end tests.
• Work with C# and .NET, using tools and frameworks such as xUnit, Reqnroll and Shouldly.
• Develop automated tests using Cypress and/or Playwright.
• Use Testcontainers and tools such as Postman or Apidog for API and integration testing.
• Integrate automated tests into CI/CD pipelines, including GitLab CI/CD and GitHub Actions.
• Work with Git, including branching strategies and merge requests.
• Manage testing activities, reporting and traceability using Jira and Xray.
• Use Grafana dashboards and alerts to monitor key quality and system indicators, such as payment throughput, error rates and asynchronous processing delays.
• Work with SQL and PostgreSQL to validate data and support testing activities.
• Collaborate closely with Developers and Product Owners to clarify requirements and identify potential quality risks early.
• Contribute to establishing and improving QA standards, testing practices and automation strategies.
• Share knowledge and support less experienced QA team members.
• Leverage AI-powered tools, such as Copilot and LLMs, to improve QA processes, automation and everyday productivity.

Role Requirements:

Must Have

• 4-5+ years of professional experience as a Tester / QA Engineer, including at least 2 years in a Senior QA role.
• Strong experience in test automation covering UI, API and/or end-to-end testing.
• Hands-on experience testing distributed systems and service integrations.
• Practical experience with REST API testing.
• Experience with asynchronous communication and event-driven architectures, including queues and messaging.
• Experience creating and maintaining functional, regression and integration tests.
• Practical experience with C# and .NET.
• Knowledge of xUnit, Reqnroll and Shouldly.
• Experience with Cypress and/or Playwright.
• Experience with Testcontainers.
• Experience using Postman and/or Apidog.
• Hands-on experience with GitLab CI/CD and/or GitHub Actions, including integrating automated tests into pipelines and modifying existing pipelines.
• Good knowledge of Git, including branches and merge requests.
• Experience with Jira and Xray for test management, reporting and traceability.
• Practical SQL skills and experience with PostgreSQL.
• Experience working in Agile environments, preferably with Kanban.
• Experience working on projects following Domain-Driven Design (DDD) principles.

Nice to Have:

• Knowledge of Docker, Kubernetes and/or OpenShift Container Platform (OCP).
• Experience with performance testing, e.g. JMeter or k6.
• Practical experience with BDD methodology.
• Proactive approach to analysing business and technical requirements.
• Strong collaboration skills and willingness to work closely with both business stakeholders and development teams.
• Experience defining quality and testing standards.
• Experience mentoring or supporting junior QA engineers.
• Openness to using AI tools and LLM-based solutions in QA, test automation and software delivery.

Perks and benefits (our offer):

• Comprehensive benefits - enjoy Udemy for Business, private medical care, Multisport card, veterinary package, language lessons, and shopping vouchers.
• Career growth - access opportunities for professional development and learning, including perks related to our official partnerships with global IT giants: Microsoft, AWS, Snowflake, Salesforce & more.
• Innovative environment - be part of a forward-thinking and growth-oriented workplace.
• Engaging community - Work with passionate professionals and participate in team-building events, hackathons, and CSR initiatives to make an impact beyond work.
• Team-building events including our company tradition (annual company event in Mazury).
• A pleasant surprise to start your journey with us in the form of a welcome pack.