Senior Quality Assurance Engineer | Contract | Remote, MX

About us: Working at Tech Holding isn’t just a job, it’s an opportunity to be a part of something bigger. We are a full-service consulting firm that was founded on the premise of delivering predictable outcomes and high-quality solutions to our clients. Our founders and team members have industry experience and have held senior positions in a wide variety of companies – from emerging startups to large Fortune 50 firms – and we have taken our combined experiences and developed a unique approach that is supported by the principles of deep expertise, integrity, transparency, and dependability. The Role We are looking for a Senior Quality Assurance Engineer for a project-based assignment to own quality across a React Native mobile application and a Next.js web experience, backed by Java/Spring Boot services behind a Node BFF. We are looking for a senior QA engineer who investigates rather than just reports. The work is hands-on: real devices, developer tools, logs, APIs, and automation, not only clicking through the UI. You will work closely with engineering, product, and design throughout feature development and release cycles. The single most important non-technical trait we are hiring for is clear communication. Key Responsibilities Testing & Investigation Execute manual and exploratory test passes against web and mobile releases, working from acceptance criteria, designs, and your own curiosity about where things break. Use browser developer tools (console, network, elements, application storage, device emulation) as a first-line diagnostic tool, not just to confirm a bug but to narrow down where it lives. Debug our React Native application on real iOS and Android devices as well as simulators and emulators: reading native device and crash logs, using React Native’s debugging tooling (Metro, the JS console, React DevTools), inspecting network traffic, working with pre-release and over-the-air builds, and reproducing issues across OS versions and device classes. Use Datadog (logs, dashboards, error tracking, RUM/session replay) to triage reported issues, confirm whether a bug is client-side or server-side, and attach real evidence to a ticket. Test REST APIs directly, not just through the UI, validating request/response payloads, status codes, error handling, and edge cases for the Java/Spring Boot services and Node BFF. Validate auth/authorization and role-based access at the API level, not just what is visible in the UI. Test service-to-service and data-pipeline behavior, e.g. confirming events land correctly downstream rather than only checking the originating call succeeded. Test idempotency, retries, and failure/edge-case handling in backend logic. Write bug reports another engineer can act on without a follow-up conversation: clear repro steps, environment, expected vs actual, logs, network calls, screenshots or recordings. Build and maintain regression suites and release checklists, and help move repetitive coverage toward automation over time. Leverage AI-assisted tooling to speed up test case generation, log analysis, and repro investigation. Communication & Collaboration Communicate clearly and proactively in standups, in tickets, in Slack, and in documents. Partner directly with engineers, product, and design during feature development rather than only at the end of it. Report on test coverage, open defects, and release risk in a way a non-engineer can follow. Surface risks, blockers, and quality concerns early rather than late, and escalate when a release should not ship. Close the loop: verify fixes, confirm they hold in the next build, and say so. Craft & Continuous Improvement Help define and evolve team standards for test coverage, bug intake, triage, and release readiness. Grow technical depth deliberately: automation frameworks, API testing, and reading enough of the codebase to make better guesses about root cause. Learn through pairing, code review participation, and documentation, and write down what you learn so the next person does not have to rediscover it. Bring a mindset of experimentation and continuous improvement. Required Skills Browser Developer Tools: You are comfortable in the developer console. You can read a JavaScript error, inspect a failing network request and its payload, check status codes and headers, work with local/session storage, and emulate a device viewport. You use it to investigate, not just to screenshot. React Native Application Debugging: You have tested and debugged a React Native app on real iOS and Android devices as well as simulators and emulators. You can pull native device and crash logs, install and manage pre-release and over-the-air builds, reproduce an issue across OS versions and screen sizes, and tell the difference between “broken on this device,” “broken everywhere,” and “broken in the JavaScript layer, not the native one.” Test Automation Ownership: You have designed and built automated test suites from scratch, not just extended someone else’s: Playwright for web, Maestro for mobile. Our web checkout flows already run on Playwright. You know what to automate vs. cover manually, and how to keep a suite from rotting into flaky noise. API Testing: Experience with Postman or comparable tools. Most of our services are Java/Spring Boot REST APIs sitting behind a Node BFF. SQL & Logs: Basic SQL (Postgres) and comfort reading structured application logs. Observability Tooling: Familiarity with Datadog or a comparable platform for logs, dashboards, and error tracking. You can search logs for a request, follow an error, and use what you find to make a bug report stronger. Strong Communication: You write clearly, explain your reasoning, ask questions when something does not make sense, and close the loop. This is the single most important non-technical trait we are hiring for. CI/CD Integration: You have wired automated tests into a pipeline (GitHub Actions or comparable) so they gate builds/deploys, and you know how to triage and reduce flaky tests rather than let a team start ignoring red pipelines. AI-Assisted Workflows: You are actively using AI tooling in your day-to-day work and can help the team push further in that direction. Nice to Have Enough TypeScript and React to read code and understand what a change touched. The mobile app is React Native; the web app is a Next.js monorepo. Comfort reading existing Jest and Testing Library unit tests well enough to tell what is already covered and what is not. Familiarity with feature flag and experimentation tooling (Optimizely, LaunchDarkly). A bug here is often flag-gated or specific to one variant. Verifying analytics and event tracking (Segment, Mixpanel, Braze) as part of a test pass, not as an afterthought. Exposure to mobile crash reporting (Sentry, Firebase Crashlytics) alongside Datadog. Familiarity with Jira and a test case management tool. Accessibility and performance testing exposure. Load testing familiarity with Gatling, Artillery, or comparable: enough to script a realistic traffic scenario against an API and read what the results are telling you. A working understanding of how a React Native build actually reaches a device: TestFlight, Play internal testing, and over-the-air updates. Location Candidates must be authorized to work in and be located in Mexico. #LI-Remote Tech Holding is proud to be an Equal Opportunity Employer and is committed to fostering a diverse and inclusive workplace. We welcome applicants from all backgrounds and experiences, and we consider qualified applicants without regard to race, color, religion, gender, sexual orientation, gender identity, national origin, disability, veteran status, or any other legally protected characteristic. If you require accommodation in the application process, please contact our HR