Senior Software Development Engineer in Test (SDET)

Goodstack; City Of London; Hybrid; GBP 70,000 - 90,000; Full time

Job summary

A fast-growing software startup in London is seeking a Senior Software Development Engineer in Test (SDET) to lead automation testing frameworks. The ideal candidate will have over 5 years of experience in QA Automation and play a crucial role in ensuring that software releases maintain high quality standards. This position offers a collaborative environment and ample opportunities for professional growth.

Benefits

Salary reviews and share options

Private health insurance

Learning & development annual budget

Paid days off to volunteer

25 days annual leave

Qualifications

• 5+ years experience in SDET, QA Automation, or Test Engineering roles.
• Strong hands-on experience in automation testing across frontend and APIs.
• Expertise in JavaScript/TypeScript for writing tests and frameworks.
• Deep experience with Playwright or similar end-to-end testing frameworks.
• Experience with API testing tools (e.g., Postman).
• Strong knowledge of CI/CD pipelines for release quality gates.

Responsibilities

• Lead the design and evolution of automation testing frameworks.
• Partner with engineers and product managers to define testable acceptance criteria.
• Own and expand end-to-end testing using Playwright.
• Improve and maintain quality gates in CI/CD pipelines.
• Mentor engineers and SDETs, raising the bar for test coverage.

Skills

Automation testing

JavaScript/TypeScript

Playwright

API testing tools

CI/CD pipelines

Holistic product mindset

Strong communication skills

Job description

If you’ve been looking to join a fast-growing startup with a bold vision of a world where doing good is built into everything we do, then you’ve found the right place!

Backed by General Catalyst, the same investors behind Stripe and Airbnb, we’re one of Europe’s fastest-growing SaaS companies – building the technology that enables global enterprises to give, volunteer, and fund with confidence.

Our Mission

Our mission at Goodstack is to revolutionize how the world does good 🌎.

As a Series A social impact startup, we power global change through technology. We enable companies to seamlessly integrate positive impact into what they do through a unified platform while supporting nonprofits in gaining access to cutting-edge technology and finding new funding streams.

Global brands, including Google, OpenAI, TikTok, LinkedIn, HSBC, Atlassian and Twilio - as well as thousands of nonprofits, including the Red Cross, Cancer Research, and Oxfam - use Goodstack to make a difference.

In 2025 alone, we have facilitated $5 billion in donations to good causes. But this is just the beginning. We're building the world’s leading platform that powers donations to nonprofits globally.

To keep our momentum and deliver consistently high value to our partners, we need incredible people to help us on our journey – we need you 🫵

Join us as Senior Software Development Engineer in Test (SDET) to ensure billions in donations reach the right causes!

We’re looking for a Senior SDET who thrives on building automation frameworks, raising quality standards, and enabling product teams to move fast with confidence.

As a senior member of our engineering team, you’ll not only deliver robust testing solutions, but also shape our quality strategy, mentor engineers, and champion testability across the stack.

If you care deeply about user journeys, love finding elegant solutions to complex testing challenges, and want to ensure that every release is something we’re proud of – this is the role for you.

As Senior SDET, your mission will be to:

• Lead the design and evolution of our automation testing frameworks for both frontend (web) and backend (APIs).
• Partner with engineers and product managers before development starts to define testable acceptance criteria and prevent defects early.
• Own and expand our end-to-end testing using Playwright and API testing tools.
• Improve and maintain quality gates in CI/CD pipelines (GitHub Actions), ensuring release confidence.
• Create and drive test strategies that balance automation, exploratory, and manual testing for complex user flows.
• Mentor engineers and SDETs, raising the bar for test coverage, reliability, and speed.
• Drive cross-team initiatives for test data management, environments, and observability of test results.
• Be a strong voice for the customer by validating holistic user flows and usability impacts.

🤝 You’ll work closely with:

• Product Engineers to design for testability and reduce defects.
• Product Managers to validate acceptance criteria and ensure releases meet customer needs.
• Platform & DevOps Engineers to optimise pipelines, environments, and release processes.
• Other SDETs/QA Engineers to set standards and share best practices across teams.

After 3 months, success will look like:

• You’ve led the delivery of a new automation capability or framework upgrade.
• You’ve reduced manual regression overhead by increasing automation coverage on critical paths.
• You’ve improved the reliability and visibility of tests in pipelines, leading to faster, safer releases.
• You’re actively mentoring engineers on writing effective tests and shaping team-wide quality practices.

This role is a perfect match for you if you have:

• 5+ years experience in SDET, QA Automation, or Test Engineering roles.
• Strong hands-on experience in automation testing across frontend and APIs.
• Expertise in JavaScript/TypeScript for writing tests and frameworks.
• Deep experience with Playwright (or similar end-to-end testing frameworks).
• Experience with API testing tools (e.g., Postman, Pact, SuperTest).
• Strong knowledge of CI/CD pipelines (GitHub Actions or similar) for release quality gates.
• A holistic product mindset – you care about the user journey and not just individual components.
• Strong communication skills and the ability to influence testing practices across teams.

Bonus if you have knowledge or love of:

• Experience in scale-ups or Series A/B startup environments.
• Exposure to non-functional testing (performance, security, accessibility).
• Experience setting up or managing test environments and fixture data.
• Knowledge of contract testing or service virtualisation.

🇬🇧 What you can expect upon joining our team

💰 Salary reviews and share options becoming an integral part of our growth and share in the company's success

💝 Goodstack’s Workplace Giving

⚕️ Vitality Plus - Private health insurance

🌞 £250 Brighten your day annual budget

🤓 £1000 Learning & development annual budget

📚 Goodstack library

🌯 Tasty Tuesday! Office lunch is on the company

🏃🏿♀️ Slow run club (Wednesdays)

⭐️ Paid days off to volunteer for non-profit causes

🎤 Paid days to attend conferences

🥳 Paid day off on your birthday!

🌴 25 days annual leave, plus paid public holidays

💙 Paid sick leave

🧘🏽 Paid wellness leave

🪁 Parental leave

⚖️ Flexible working hours

🖥️ WFH budget upon joining

🧓🏽 Pension

🚴🏾 UK cycle-to-work scheme

🌳 Ecologi Carbon Offsetting

🏡 You're always welcome to pop in more often if you enjoy the buzz of being in the office. It's a warm, friendly space right in the heart of London

🙌 … and so much more

About us

Since 2017, Goodstack has been at the forefront of creating a future where good will be built into everything we do. From daily commutes to weekend activities or grocery shopping, we envision a world where creating positive change is seamlessly integrated into our everyday lives. In this future, the depth and breadth of impact we can make through everyday actions will expand dramatically – benefiting both businesses and the world.

Businesses are expected to deliver on both profit and purpose and those that don’t are falling behind. We’re here to make it easy for any company, anywhere in the world, to integrate good into what they do. Doing this empowers everyone – companies, employees, consumers, and communities – to contribute to positive change and take meaningful action.

Let’s do this! 💜

OUR PLEDGE TO DIVERSITY, EQUITY & INCLUSION

We take pride in our diverse and growing team representing 20+ nationalities across 5 continents 🌍! Our continued expansion provides us with opportunities to embrace and celebrate different backgrounds, perspectives, and experiences, essential to our success. We actively seek and welcome applicants from all walks of life, regardless of race, religion, colour, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.

A team that represents the world that we are trying to support is a wiser, more knowledgeable and stronger one. We’re excited for you to bring your experience, yourself and your special lemon twist to Goodstack to propel us forward in striving to create a better world for us all.

Check out our Careers Page for more details!