Sr. Quality Assurance Engineer, PLC Automation at ON.energy

<div class="content-intro"><p>ON.energy<span class="Apple-converted-space">&nbsp;</span>is setting the standard for large load interconnection. ON’s patented AI UPS™ is a medium-voltage UPS that serves as a firewall, protecting the data center from the grid, and the grid from the data center.&nbsp;With multiple gigawatts currently under construction, we are enabling grid-safe data centers.&nbsp;</p></div><p>The Sr. 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>#LI-AD1</p> <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>Benefits vary by role and location and are subject to change.</li> </ul> <p><strong data-start="453" data-end="471">Agency Notice:</strong><span class="Apple-converted-space">&nbsp;</span>ON.energy does not accept unsolicited resumes from staffing agencies, search firms, or third-party recruiters. Resumes submitted without a fully executed Master Services Agreement (MSA) and a written request from an authorized member of our Talent Acquisition team will be considered the property of ON.energy. No placement fees or compensation will be paid for unsolicited candidate submissions.</p></div>