PLC Automation Engineer at ON.energy

<div class="content-intro"><p>ON.energy is building the power infrastructure that makes the AI era possible. As AI demand surges past what the grid and traditional data centers can support, ON.energy provides a new class of power technology proven at gigawatt scale and trusted by the world’s leading cloud and AI companies. Our systems are already deployed across 2.5 GW of hyper-scale campuses, validated by top U.S. national labs, and certified for grid-safe operation by major utilities. With real products in the field, we’re scaling faster than the grid can, transforming power from a bottleneck into a competitive advantage for the companies building the future.</p></div><p>The Quality Assurance Engineer is responsible for hands-on experience in PLC programming, industrial protocol testing, and Python-based test automation. Skilled in designing and executing functional and integration test cases across PLC platforms and communication protocols.</p> <p><strong>Key Responsibilities:&nbsp;</strong></p> <ul> <li>Design, develop, and execute Unit tests, functional, integration, and regression test cases for PLC-based control systems</li> <li>Write and maintain Python-based automated test scripts for testing PLC I/O, HMI interfaces, and communication protocols</li> <li>Develop, review, and validate PLC code (Ladder Logic, Function Block Diagram, Structured Text) across Siemens S7-1200/1500</li> <li>Collaborate with controls engineers to define acceptance criteria and validate system requirements</li> <li>Identify, document, and track defects using tools such as Azure Devops or equivalent; lead root cause analysis for critical failures</li> <li>Conduct Hardware-in-the-Loop (HIL) and Software-in-the-Loop (SIL) testing where applicable</li> <li>Produce clear test plans, reports, and traceability matrices aligned with release timelines</li> </ul> <p><strong><br>Required Experience &amp; Skills</strong></p> <ul> <li>University degree in Software Engineering, Computer Science, Quality Engineering, or a related technical field.</li> <li>5+ years of hands-on experience in PLC programming and testing across Siemens platform.</li> <li>5+ years of experience building and maintaining automated test frameworks using pytest or equivalent python framework.</li> <li>3–5 years of experience with Siemens TIA Portal for PLC development, diagnostics, and commissioning support.</li> <li>Experience designing and executing functional and integration tests, including test case development, defect tracking, and validation of fixes.</li> <li>Working knowledge of industrial communication protocols such as S7, Modbus TCP/RTU, and OPC-UA.</li> </ul> <p>Preferred Experience</p> <ul> <li>Proficiency in automated unit testing the PLC Logic</li> <li>Experience with SCADA systems</li> <li>Familiarity with Agile / Scrum methodologies in industrial settings</li> <li>Knowledge of functional safety standards such as IEC 61508 / IEC 62061</li> </ul> <p>&nbsp;</p><div class="content-conclusion"><hr> <p><strong>For US-based roles - What you’ll get:</strong></p> <ul> <li>Competitive salary + annual performance-based bonus eligibility</li> <li>Medical, dental, and vision insurance</li> <li>401(k) with company match</li> <li>Paid time off and company holidays&nbsp;</li> </ul> <p><strong>For Mexico-based roles - What you’ll get:</strong></p> <ul> <li>Competitive salary + annual performance bonus eligibility</li> <li>Christmas Bonus (Aguinaldo): 30 days</li> <li>Major medical expenses and life insurance</li> <li>Paid time off and holidays (per local policy)</li> </ul> <p><strong>For all roles:</strong></p> <ul> <li>Professional development and growth opportunities</li> <li>Opportunity to grow with a mission-driven team shaping the future of clean energy</li> <li>Equal Opportunity: ON.energy is committed to equal employment opportunity and to maintaining a work environment free of harassment, discrimination, or retaliation.</li> <li>Accommodations: If you need an accommodation during the application process, email <a href="mailto:[email protected]">[email protected]</a></li> <li>Benefits vary by role and location and are subject to change.</li> </ul></div>