Controls Engineer, PLC Programming

About this role

Fluidstack seeks a Controls Engineer to develop scalable PLC programs for data center mechanical systems across a 50GW+ deployment. You'll create reusable, portable code across multiple PLC platforms and validate it on real hardware before fleet-wide rollout.

What you'll do

• Design and test template PLC programs for chillers, CRAHs, fan walls, and other mechanical equipment
• Write portable code across Siemens, Codesys, and virtualized PLC platforms
• Convert sequences of operations into functional PLC code with the controls and mechanical teams
• Install and wire PLCs, sensors, and IO in lab environments for pre-deployment validation
• Debug programs against real hardware and failure conditions to catch issues before field deployment
• Build structured, reusable code that other engineers can maintain and adapt

What they're looking for

• PLC programming for mechanical equipment (chillers, air handlers, pumps)
• Multi-platform PLC experience (Siemens, Codesys, virtualized environments)
• Structured Text and IEC 61131-3 languages
• Hardware installation and wiring (PLCs, IO, sensors)
• Fault diagnosis and physical layer troubleshooting
• BACnet and Modbus protocol integration
• Hardware-in-the-loop and virtualized PLC testing
• Data center mechanical systems knowledge

Benefits

• Competitive salary: $200,000–$250,000 annually
• Equity compensation in the form of stock options
• Opportunity to work on civilization-scale AI infrastructure
• Extreme autonomy and end-to-end ownership of projects
• High-velocity, first-principles engineering culture

Likely interview questions

• Walk us through a time you debugged a PLC program that ran fine in simulation but failed on real hardware—what was the root cause?
• Describe your experience with multiple PLC platforms. How did you approach writing portable code across different vendors?