WHO IS LITMUS Litmus is building the data foundation that powers industrial AI. AI doesn’t work without real-world, contextualized data - Litmus makes that data usable. As AI adoption accelerates, most industrial environments still can’t access or use their operational data. We solve that gap. We’re a growth-stage software company helping manufacturers access, structure, and use real-time data from machines, systems, and sensors at the edge. Our platform sits at the intersection of edge computing, AI, and industrial operations, enabling some of the world’s largest companies to run operations in real time, reduce downtime, and optimize production. Backed by leading investors and trusted by global manufacturers and partners like Google, Microsoft, Dell, Oracle, and Mitsubishi, Litmus is powering the shift toward software-defined manufacturing. WHY JOIN LITMUS BUILD THE INFRASTRUCTURE THAT MAKES INDUSTRIAL AI POSSIBLE AI is moving beyond the cloud and into the physical world. At Litmus, you’ll build the infrastructure that enables real-time data to power AI and machine learning systems in production environments. WORK ON PROBLEMS WHERE SOFTWARE MEETS THE REAL WORLD Most AI systems fail without access to real-world data. You’ll build the layer that makes them viable in production. We solve challenges at the intersection of distributed systems, real-time data, and industrial constraints — where reliability, scale, and performance are non-negotiable. HAVE REAL IMPACT, FAST You’ll work on systems used by real customers in production, with direct impact on product and company trajectory. As a scaling company, we move quickly. You’ll have ownership, visibility, and the ability to shape both product and company as we scale. JOIN A HIGH-PERFORMANCE TEAM We’re building a team that holds a high bar and pushes each other to improve. You’ll work alongside experienced operators, engineers, and leaders who have done this before and are building again at scale. We hire people who take ownership, move quickly, and care about outcomes. No passengers. OUR CULTURE At Litmus, the team is collaborative, curious, and low ego. People are scrappy, take ownership, and look for ways to make an impact. We value empathy just as much as execution, whether that’s in how we build, how we communicate, or how we support each other. We’re a growing company, so things move quickly and not everything is perfectly defined. If you enjoy figuring things out, working closely with others, and making steady progress, you’ll do well here. ABOUT THE ROLE We are hiring a Senior QA Test Engineer (SDET) for our Industrial and Data team. Today the developers on this team test their own work, so the connectors that talk to PLCs and industrial control systems have no independent test coverage. You will own that coverage. This is a role where you write code, not test documents. Your output is the automation framework, the regression suite that runs on every build, and the device and protocol simulators that let us test without waiting for physical hardware. You will sit with the industrial developers and work closely with the engineering team in the US and Canada.   WHAT YOU'LL DO • Build and own automated test coverage for the southbound connectors that use OPC-UA, Modbus, EtherNet/IP, PROFINET and DNP3. • Write end to end tests that drive Litmus Edge through its REST API, and keep them running in our GitLab pipelines on every internal build. • Build protocol and device simulators, so tests do not have to queue for physical devices that only accept one connection at a time. • Split coverage into development tests and regression tests, and run the regression suite on LTS builds and on an agreed cadence. • Test upgrade and backward compatibility paths, behaviour under load, and longer soak runs. • Triage failures from pipeline logs and report them with a clear timestamp, separating product bugs from infrastructure noise. • Keep test cases and results in Jira and Xray so we can report coverage per component. • Review acceptance criteria on tickets when development starts, not after it finishes.   WHAT YOU'LL BRING Must Have • 5+ years in software test automation, including at least 3 years writing test code in Go, Python or a similar language. This is not a manual or record and playback role. • Hands on REST API test automation, including building and changing system state through API calls. • Working knowledge of at least two industrial or IIoT protocols, for example OPC-UA, Modbus, EtherNet/IP, PROFINET, DNP3 or MQTT. • Comfortable with Linux, Docker and CI pipelines (GitLab preferred), including reading pipeline logs to work out why a run failed. Nice to Have • Experience building device or protocol simulators, or hardware in the loop test setups. • C++ or Golang development experience, since much of the team's code is written in those languages. • Playwright or similar modern UI automation. Litmus is standardising its automation on Playwright. • Jira and Xray for test case and test execution management. • A high level understanding of PLCs, for example the difference between memory tags and symbolic tags. • Performance, load or soak testing experience. Option to be hybrid in Santa Clara or Toronto, or remote in the US or Canada.