QA Automation Engineer (Senior)

About the Role

• Build evaluation suites for LLM and ML features: curated test sets, scoring against reference answers, LLM-as-judge where it is justified, and human review where it is not.
• Define what "good enough" means with the delivery team before launch, in numbers a client can accept, and hold releases to it.
• Test retrieval pipelines end to end, covering chunking and indexing, retrieval quality, grounding of the final answer, and behaviour when the right document is simply not there.
• Write regression tests that tolerate non-deterministic output, using semantic similarity, structured-output validation, tolerance bands, and repeated sampling rather than exact string matching.
• Cover failure modes that matter to clients: hallucination, prompt injection through user or document content, leakage of data across tenants or sessions, refusal and over-refusal, and degradation on Thai-language input.
• Track cost and latency alongside accuracy, so that a quality improvement that triples token spend is visible before it ships.
• Detect drift after release by comparing production samples against the baseline, and raise it early rather than after the client does.
• Design and maintain automated test suites for APIs, services, data pipelines, and web applications built for client projects.
• Run tests in CI, keep them fast and stable, and treat a flaky suite as a defect in its own right.
• Set the test strategy at the start of an engagement: what gets automated, what stays manual, what the exit criteria are, and what evidence the client will receive.

Qualifications

• 4-5 years in test automation, QA engineering, or software engineering with substantial testing ownership.
• Strong programming ability in Python, or in TypeScript or Java with the willingness to work primarily in Python.
• Hands-on experience testing an LLM or ML-based product in production or close to it.
• Practical command of at least one automation framework such as Pytest, Playwright, Cypress, or RestAssured, and experience running suites in CI.
• Working knowledge of API and data testing, including SQL and validating data through a pipeline.
• The judgement to decide what deserves automation and what does not, and to say so when a suite is producing noise rather than signal.
• Clear written and spoken communication in Thai and English.

Benefits

• Hybrid Working options with Flexible Working Hours.
• Your Choice of Gear: Mac or Windows? You pick your preferred work equipment.
• Comprehensive Group Health Insurance.
• Monthly Grab Transportation credits.
• Job-related training courses and certificate fee coverage.
• 10+ days of annual leave.
• Free snacks and drinks available at the office.