Senior QA Engineer - Kafka & Event Streams

BUX; Amsterdam; On-site; EUR 90,000 - 130,000; Full time

Job summary

BUX is seeking a Senior Quality Assurance Engineer (Event Streaming) in Amsterdam to own QA for our backend broker and Kafka‑driven systems. You will design, implement, and maintain automated and manual tests for producers, consumers, and event flows, and ensure delivery guarantees and schema compatibility across services.

You will collaborate with Product and Development, participate in design reviews, and help mature QA processes in a fast‑paced fintech environment.

Qualifications

• 5–7+ years of experience in software quality assurance, with a senior‑level track record in fintech.
• Hands‑on testing experience with Kafka or comparable event‑streaming platforms.
• Strong knowledge of API testing (REST) and microservices/event‑driven architectures.
• Hands‑on experience with test automation frameworks such as Selenium and Playwright with TypeScript.
• Proficiency in at least one programming language (Java/Kotlin).
• Understanding of CI/CD pipelines and GitHub Actions integration.
• Practical experience with Postman/Newman, Charles Proxy, and Xray (or similar test‑management tooling).
• Comfortable validating data across multiple databases and asynchronous event flows.

Responsibilities

• Design, develop, and maintain automated and manual tests for Kafka‑based producers, consumers, and event flows.
• Execute manual and exploratory testing where automation is not feasible.
• Integrate automated test suites into CI/CD pipelines (GitHub Actions).
• Help build and mature QA processes and standards for event‑driven systems within the squad.
• Apply quality gates and acceptance criteria with Product and Development teams.
• Participate in design reviews to provide QA perspective early in the cycle.
• Monitor quality metrics, test coverage, and defect trends for streaming domain.
• Validate message ordering, delivery guarantees, idempotency, and exactly‑once/at‑least‑once semantics.
• Validate producer and consumer contracts and schema compatibility as services evolve.
• Perform failure‑mode and resilience testing (broker failures, replay scenarios).
• Support test environment setup and data provisioning with DevOps.
• Use approved GenAI tooling with sanitized data to accelerate test design and automation, subject to review.

Skills

Kafka testing

API testing REST

Selenium

Playwright

TypeScript

Java/Kotlin

CI/CD (GitHub Actions)

Postman/Newman

Charles Proxy

Xray

GCP

Kubernetes

CI/CD pipelines

Agile / Scrum

Tools

Kafka

Spring Boot

GCP

Kubernetes

GitHub Actions

Postman

Newman

Charles Proxy

Xray

CloudSQL

PostgreSQL

Job description

BUX is seeking a Senior Quality Assurance Engineer (Event Streaming) in Amsterdam to own QA for our backend broker and Kafka‑driven systems. You will design, implement, and maintain automated and manual tests for producers, consumers, and event flows, and ensure delivery guarantees and schema compatibility across services.

You will collaborate with Product and Development, participate in design reviews, and help mature QA processes in a fast‑paced fintech environment.