From acceptance criteria to test cases
I use Claude to turn acceptance criteria into scenarios ready to automate, including the edge cases that are easy to miss.
QA Automation Engineer. Based in Brazil, open to bringing confidence to teams anywhere in the world.
Gabriel Castro
Software breaks. I build the test suites that bring consistency, so teams can ship big changes with confidence.
2,917 testsacross 3 production systems
637 spec files 715 suites 40–50 CI/CD pipelines
About
Five years in test automation, most of it owning end-to-end coverage for a SOC 2 fintech platform in the US debt-sales market: three production systems, nearly 3,000 automated tests, and the pipelines that ran them every day.
I came to QA from web design and development, so I read a UI the way a designer does and a codebase the way a developer does. AI is part of how I work every day, and I treat what it produces the way I treat any code: as something to test before trusting.
How I use AI
AI speeds up every part of my testing. The final call is always mine.
Modern test automation isn’t just about writing test code. It’s about deciding what deserves trust when machines build alongside us.
Review before trust
Every AI-generated test case gets checked against the real requirements, which is also how I find gaps in coverage.
Writing and running tests
Claude Code alongside Playwright, with Playwright MCP to drive the browser. I review and own every line it writes.
Failures and bug reports
AI reads the failure logs with me to get to the root cause faster, then helps draft clear bug reports.
Projects
Things I build for testing and for the people who test.
Frogeye Reporter
A dashboard for Cypress and Playwright runs
A test reporting dashboard for Cypress and Playwright. It reads results straight from CI and keeps the history of every run, so after each one a team can see what needs attention, not only what passed and what failed.
- Now
- Results from each CI run: pass rate, new failures, flaky tests and retries, with product defects kept apart from test defects.
- History
- Every run is kept, so you can compare runs and follow how the suite evolves: pass rate, failures and duration over time, the best and worst runs, and the overall trend.
- AI
- Coming next: every failure explained in plain words, with the likely cause and where to look first. Works with Claude, OpenAI or Gemini.
- Debug
- Coming next: traces, videos and logs for every attempt, and quarantine for unstable tests without touching the code.
Vagalume
A job board built to be tested
A fictional job board I built as a practice target for software testers. Candidates apply to jobs, companies move applicants across a kanban board, and a small course store has a cart, coupons and checkout. Some of it fails on purpose.
- UI
- Shadow DOM, an iframe, drag and drop, a cookie banner, a broken image, and a data-testid on nearly every element.
- API
- 60 documented operations in OpenAPI 3 with Swagger UI, ready for contract testing in Postman or code.
- Data
- PostgreSQL 16 in Docker, so tests can check what the screen can’t show.
- Failures
- Checkout returns 502 about 15% of the time, coupons are rate-limited, and there are slow and flaky endpoints to test against.
- Built
- With AI assistance, as a practice target rather than production code.
| Item | Value | Note |
|---|---|---|
| Admin action (500) | 35% | 2.5–4 s response |
| Checkout (502) | 15% |
- 400
- 401
- 403
- 404
- 409
- 422
- 429
- 502
4xx client errors 5xx server errors
Coming soon
Vagalume is the target. Next come the test suites that run against it, each in its own public repository, so you can watch them catch the failures Vagalume throws on purpose. New versions of Vagalume will keep adding things to test.
- Nov 10
Cypress suite for Vagalume
UI and API tests written in Cypress.
- Nov 30
Playwright suite for Vagalume
UI and API tests written in Playwright, with their own set of scenarios.
- TBA
REST Assured suite for Vagalume
API tests in Java, driven by the OpenAPI contract.
Big changes, nothing broken
Platform-wide changes the test suite carried the product through.
GraphQL to REST
The whole API layer was replaced. The E2E suite was the safety net that confirmed every flow still behaved the same from the user’s side.
In-house component library
Helped design the components, then kept the regression suite green while every screen moved over to them.
Authentication moved to Auth0
Rebuilt login handling across the suite so tests kept running against the real identity provider.
Dark mode
A visual change touching every page. Combined automated checks with design-QA reviews to catch contrast and layout regressions.
Experience
- 2021 – 2026
QA Automation Engineer
300 Softwares, placed with a US fintech platform
Owned test automation for three production systems on a SOC 2 fintech platform, from test strategy to the daily CI pipelines, with AI built into the workflow.
- 2017 – 2021
Programmer and Web Designer
Built web applications and WordPress sites from Figma to code, with JavaScript on the front end, and did the functional testing that eventually became my job.
- 2014 – 2025
- 2011 – 2021
Photographer New website coming soon
Independent; sports photojournalist for Metro and ESPN Brasil
Where my eye for detail comes from. Over those years I was also invited to give several talks.
Lead photographer for the book O Atleticano Vai ao Paraíso, by Fred Melo Paiva Buy
Education
- In progress: In progress Postgraduate degree in Software Quality Engineering and Testing PUC Minas
- Completed: 2021 Software Testing / QA certificate Última School
- Completed: 2009 Creative Enterprise Ownership Fashion Institute of Technology (FIT), New York
- Completed: 2005 – 2009 B.A. in Social Communication, Advertising PUC Minas
Tools I use
- Automation
- Cypress
- Playwright
- JavaScript (ES6+)
- TypeScript
- Page Object Model
- API testing
- REST API testing
- Test data through the API
- CI/CD and data
- Git
- Azure DevOps
- Azure Pipelines
- SQL
- Auth0
- Practice
- E2E, regression and integration testing
- Test parallelization
- BDD (Gherkin)
- Test data management
- Agile / Scrum
- AI-assisted testing
- Claude
- Claude Code
- GitHub Copilot
- Gemini
- Playwright MCP
- Performance
- k6
- Design
- Figma
- Adobe Creative Suite
- UI/UX