Software Development Engineer in Test (SDET)

Location: Redwood City, CA

Our mission is to move humanity off of fossil fuel heating. 20% of US global warming emissions come from homes (that's more than cars!). The largest driver of home emissions is burning fossil fuels for heat. To stop climate change, over 80M US homes need to transition from combustion to efficient, electric heat pumps over the coming decades.

We believe for this to happen the world needs fantastic products that are easy to purchase. Today's heat pumps lack great design, make limited use of software, and are difficult and stressful to adopt. We are building a next generation, beautifully designed, AI optimized home heating and cooling system that is 10x better than what is on the market today.

Role

Quilt is hiring an SDET to build and scale test infrastructure for our heat pump products across embedded systems, cloud services, and mobile platforms. We're looking for someone who sees manual testing as a problem to automate, not a job to do. You'll work alongside a talented embedded and cloud engineering team, building the frameworks, simulators, and CI/CD pipelines that enable fast, confident releases. This is an infrastructure-building role with high leverage—your work will multiply the productivity of the entire engineering team.

We have hardware-in-the-loop test rigs and device simulators already in place. Your job is to expand them, make them easier to use, and drive adoption across the team. You'll also partner closely with embedded engineers to improve code testability—making it very easy for them to write unit and integration tests.

Responsibilities

Test Infrastructure & Automation (60%)

• Build and maintain CI/CD pipelines for embedded, cloud, and mobile testing (GitHub Actions, Bazel)
• Extend hardware-in-the-loop (HIL) test infrastructure for device commissioning, OTA updates, and telemetry validation
• Develop device simulators and mocks to reduce hardware dependencies in testing
• Automate repetitive manual test scenarios into regression suites (e.g., pairing flows, firmware upgrades, cloud integration)
• Create reusable test fixtures and libraries that make it easy for engineers to write tests
• Debug and eliminate flaky tests; improve CI reliability and speed

Test Infrastructure & Engineering Support (30%)

• Build test fixtures, utilities, and templates that make it easy for embedded engineers to write tests
• Design testable interfaces and mock layers for device features
• Provide C++ test examples (gtest) for common embedded patterns
• Collaborate on architecture decisions to ensure new features can be tested efficiently
• Improve developer experience around writing and running tests locally and in CI
• Document testing patterns and best practices for embedded systems

Quality Validation & Release Support (10%)

• Perform hands-on testing of critical release scenarios (device pairing, OTA, mobile app integration)
• Validate firmware changes with automated and exploratory testing
• Support mobile app testing (iOS/Android) for key user flows
• Triage and reproduce customer-reported issues for engineering teams

Minimum Qualifications

• 4-6 years of SDET or test automation experience, ideally with IoT, embedded systems, or hardware products
• Strong Python for test automation (pytest framework highly preferred)
• Experience with hardware-in-the-loop (HIL) testing or device integration testing
• CI/CD pipeline development and maintenance (GitHub Actions, CircleCI, or similar)
• Comfortable with Linux/Unix environments and shell scripting
• Experience influencing engineering practices—you've convinced developers to refactor code for testability
• API testing for REST/gRPC services
• SQL/database testing for telemetry or time-series data validation
• Strong debugging and problem-solving skills for complex hardware/software s