Principal SDET (Software Development Engineer in Test)
If you have a passion for catching issues before customers do, love writing rock-solid automated tests, and want to help elevate our product quality at Paystone, this role is for you!
As a Principal SDET (Software Development Engineer in Test) you’ll define our automated test strategy, expand test coverage, and empower every engineer to ship confidently by building robust, comprehensive tests.
Reporting to: VP, Engineering
Department: Engineering
What You'll Be Doing:
Test Automation & Technical Leadership
- Design, build, and maintain robust automated test suites using Jest (API / integration) and Playwright (end-to-end, cross-browser). Review application architecture to identify risk areas and define the right test pyramid (unit integration
- E2E).
- Establish and document coding standards for test automation; perform PR reviews to uphold them.
- Investigate test failures quickly, triage defects, and collaborate with developers on root-cause analysis.
Quality Process Improvement
- Champion shift-left testing: embed quality gates in every stage of the SDLC and CI/CD pipeline.
- Analyze flakiness, execution time, and coverage metrics; drive continuous optimisation.
- Introduce tooling (static analysis, mutation testing, visual regression, etc.) when it meaningfully boosts product quality.
Cross-Team Collaboration & Facilitation
- Partner with Product Owners and Squad Leads to turn acceptance criteria into executable automated tests.
- Act as a quality mentor: run workshops, pair-program on test patterns, and nurture a culture of ownership.
- Review upcoming technical designs with an eye on observability and testability, providing actionable feedback early in the lifecycle.
Planning & Delivery
- Estimate and prioritise test automation work in sprint planning, balancing risk and velocity.
- Provide clear visibility into test coverage, defect trends, and release health to stakeholders.
- Ensure test environments and data are version-controlled, reproducible, and aligned with production.
What We're Looking For:
- Proven success improving product quality for SaaS solutions in an agile environment.
- Deep hands-on expertise with Jest and Playwright (or similar frameworks) and solid TypeScript/JavaScript skills.
- Experience integrating automated tests into cloud-based CI/CD (GitHub Actions, GitLab CI, etc.).
- Strong understanding of testing strategies (TDD, BDD, contract testing, accessibility, performance).
- A collaborative, solution-oriented mindset with crisp, confident communication.
- Passion for mentorship and driving a culture of quality across engineering teams.
Whether you’re already a senior automation specialist or an experienced developer passionate about quality, this role lets you broaden your impact while staying deep in the code.
Let’s raise the bar on reliability — together.
qlutHJGZwZ