Software Engineer - Test Automation (SDET)

The role At Mach9, Test Automation Engineers protect the workflows that civil engineers and surveyors rely on when they work in our browser-based 3D CAD platform. Coding agents do a growing share of our development work, but that only works when we have automated checks that return fast, trustworthy answers. You'll own the accuracy of those answers — giving us coverage that spans from data upload to deliverable export — and the test infrastructure it runs on. This role is ideal for engineers who have built and maintained automated test suites for production web applications and can chase a failure through app code and infrastructure all the way to its root cause. Working closely with our platform engineers, you'll help us ship confidently while shipping quickly. Success in this role will mean that our regressions will be caught by tests rather than by customers, and our engineers and agents will move faster because they'll know that your tests tell them immediately when they break something. Where you will make an impact Grow automated coverage across our CAD editor and drive pages Evolve our test infrastructure and CI so our test suite stays fast and reliable as its coverage grows Build tools for coding agents to reproduce the failures and artifacts that they need to diagnose regressions and verify fixes Root out flaky tests so a failing build always means there's a real bug Make our 3D editor more testable so we can automatically test our users' CAD workflows Help other engineers write testable code and durable tests to go with every feature What you bring 3+ years building and maintaining automated test suites for production web applications with Playwright, Cypress, WebdriverIO, or similar Proficiency in TypeScript or JavaScript, and comfort reading and changing application code Experience building or substantially evolving an E2E test framework: fixtures, test data, isolation, parallel execution, and flakiness control Experience integrating tests into CI and keeping pipelines fast and reliable Interest in AI-assisted development and using agents to improve software quality Experience with performance regression tracking Experience testing CAD, 3D, geospatial, mapping, high performance editor, or gaming products About Mach9 Mach9 is transforming civil infrastructure design with AI-powered geospatial tools. Our platform accelerates the creation of engineering deliverables from raw data, cutting manual drafting time by 96×. Trusted by global leaders in engineering and construction, we're backed by Y Combinator, Quiet Capital, and top founders and executives from Cruise, Autodesk, Adobe, and DoorDash. We believe the needs of a startup benefit from an in-person culture. The team works from our office in SoMa five days a week, with flexibility when needed. Visa sponsorship is available for this role.