Senior Quality Assurance Engineer (Backend)

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

Job summary

BUX is looking for a Senior Quality Assurance Engineer (Backend) to join the Amsterdam-based engineering team. You will drive backend test automation, ensure financial accuracy, and safeguard regulatory compliance in a fintech platform.

You will collaborate with Product and Development to define done criteria, build robust QA processes, and monitor test coverage and quality metrics across services. This is a hands-on, fast-paced role with modern tech.

Qualifications

• 5–7+ years of software QA experience with hands-on testing in fintech.
• Strong manual and exploratory testing skills with test automation experience.
• Strong API testing (REST) knowledge and microservices/event-driven architectures.
• Hands-on with Selenium and Playwright using TypeScript.
• Proficiency in Java or Kotlin and CI/CD with GitHub Actions.
• Experience with Postman/Newman, Charles Proxy, and Xray.
• Ability to validate data across databases and event flows.
• Experience improving QA processes in Agile squads.

Responsibilities

• Design, develop, and maintain automated tests for backend REST services.
• Execute manual and exploratory testing where automation isn't feasible.
• Help build and mature QA processes and definitions of done.
• Apply quality gates and acceptance criteria with Product and Dev teams.
• Participate in design reviews to provide QA perspective early.
• Monitor quality metrics, coverage, and defect trends for backend services.
• Perform bug triage, reproduction, and prioritisation with Dev teams.
• Integrate regression, smoke, and integration tests into CI/CD (GitHub Actions).
• Support test environment setup and data provisioning with DevOps.
• Utilize GenAI tooling with sanitised data for test design, with human review.

Skills

5–7+ years exp

Manual testing

Exploratory testing

API testing (REST)

Selenium

Playwright

TypeScript

Java

Kotlin

CI/CD (GitHub Actions)

Postman/Newman

Charles Proxy

Xray

SQL / DB verification

QA processes in squad

Agile

Communication

Collaboration

Tools

Selenium

Playwright

Postman

Newman

Charles Proxy

Xray

GitHub Actions

Job description

We are looking for a Senior Quality Assurance Engineer (Backend) to join our BUX team based in Amsterdam.

Our engineering team sits at the heart of the company. We have a well-rounded team that cares about building great products that matter. You'll be part of a modern fintech company where you can try things, break things, fix them, and learn fast. Your work is visible, your input matters, and you help shape both the product and how we build it. We stay close to what's happening in the world of investing and fintech, and we share what we learn. It's a place where you can stretch your skills, contribute to something real, and grow alongside people who take their craft seriously and enjoy building things together.

What you will do

In a fintech environment, quality is not just about catching bugs; it's about ensuring financial accuracy, maintaining regulatory compliance, and safeguarding our users' trust. You'll play an active hands‑on role in upholding quality across the backend services that power our platform.

As a Senior Quality Assurance Engineer for our App Backend team, your job is to get things done. This could mean:

• Design, develop, and maintain automated tests (integration, end-to-end, regression) for backend REST services
• Execute manual and exploratory testing where automation is not feasible
• Help build and mature QA processes, standards, and definition of done within the squad
• Apply quality gates and acceptance criteria in close collaboration with Product and Development teams
• Participate in design reviews for owned backend features to provide a QA perspective early in the development cycle
• Monitor and track key quality metrics, test coverage, and defect trends for backend services
• Perform bug triage, reproduction, and prioritisation with development teams
• Integrate automated regression, smoke, and integration test suites into CI/CD pipelines (GitHub Actions)
• Support test environment setup, data provisioning, and maintenance in coordination with DevOps
• Use approved GenAI tooling with sanitised data to accelerate test design and automation, subject to human review, security policies, and validation of generated tests

Java, Kotlin, Spring Boot, GCP, Kubernetes, GitHub Actions, REST APIs, Selenium, Playwright/TypeScript, Postman/Newman, Charles Proxy, Xray, CloudSQL, PostgreSQL

What you need to succeed

We are looking for you if you are passionate about quality, you have strong hands‑on testing skills, and you thrive in a fast‑paced fintech environment. Furthermore, we require:

• 5–7+ years of experience in software quality assurance, with a senior‑level track record of hands‑on testing in the fintech domain
• Strong hands‑on manual and exploratory testing skills alongside solid test automation experience
• 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 integration of automated tests (GitHub Actions)
• Practical experience with Postman/Newman, Charles Proxy, and Xray (or similar test management tooling)
• Comfortable validating data consistency across multiple database technologies and asynchronous event flows
• Experience helping establish or mature QA processes within a squad or team
• Experience working in a fast‑paced Agile environment
• Excellent communication and collaboration skills with cross‑functional teams
• This role reports to the Staff QA Engineer

Nice‑to‑haves

• Experience with fintech or financial services testing (financial accuracy, transactional data, regulatory compliance)
• Experience with performance and security testing
• Knowledge of financial regulations and compliance standards (KYC/AML)
• Familiarity with event‑driven and event sourcing architectures

Why join BUX as a Senior QA Engineer?

• You will have a real impact on quality for a high‑growth fintech company that serves thousands of users
• You will work with modern backend technologies and have the freedom to introduce better testing practices
• You'll collaborate with experienced, passionate engineers who value quality and continuous improvement
• You'll be part of a company that values your ideas and encourages innovation at every level
• You will help build products that democratize investing and make a real difference in people's financial lives

Read more here about the benefits and perks you receive when you join BUX.

BUX for everyone

At BUX, we’re committed to making investing accessible and affordable for everyone through our intuitive app. We believe that a diverse team with a range of backgrounds, skills, and perspectives is key to achieving this mission. By embracing diversity, we strengthen our ability to innovate and serve our customers better.

To fully benefit from our diversity, it’s essential that everyone feels safe, included, and valued. We are dedicated to creating a workplace where each of us can bring our full selves to work and contribute to our shared goals.