Senior Automation Software PLC Engineer - Critical Infrastructure

As a master system integrator (MSI), Smart Tech Contracting excels in streamlining complex building automation system (BAS) and technology integrations, offering a comprehensive turnkey package that includes DDC, PLC, and SCADA solutions.

We offer systems design, graphical standards development, central plant optimization (CPO), enterprise-level energy and operational monitoring, and robust alarming solutions. Our expertise in hyperscale and colocation data center integrations ensures seamless, efficient operations vital in today's data-driven world.

As the Senior Automation Software PLC Engineer – Critical Infrastructure, you’ll architect high-availability PLC systems, lead Level 2–5 commissioning, and push the boundaries of automation under live pressure. This is a hands-on, high-impact engineering role based in Atlanta, GA, where precision, speed, and resilience define success.

Position Title: Senior Automation Software PLC Engineer – Critical Infrastructure

Position Location: Must relocate to or live in Atlanta, GA area

SALARY

Smart Tech Contracting recognizes salary ranges from job boards do not necessarily reflect our pay ranges. In many instances we out-compete those ranges for well-qualified candidates.

JOB SUMMARY

The Senior Automation Software PLC Engineer – Critical Infrastructure owns the complete PLC software life‑cycle for hyperscale and colocation data‑center campuses ranging from 10 MW to 200 MW+. You will architect, program, and lead level 2/3/4/5 commissioning of high‑availability PLC solutions that integrate mechanical, electrical, and IT/OT subsystems—ensuring Tier III/IV reliability while meeting aggressive speed‑to‑market schedules.

The Senior Automation Software PLC Engineer – Critical Infrastructure will serve as the PLC subject‑matter expert (and secondary SME on SCADA development and SCADA integration) to ensure seamless hand‑offs, tag mapping, and site testing. You will Lead development of PLC logic, modular function blocks, state machines, and fault‑tolerant control strategies across multiple projects.

The Senior Automation Software PLC Engineer – Critical Infrastructure will coordinate closely with field electricians, startup & commissioning technicians, and the SCADA Engineer to validate end‑to‑end data flow, alarms, and historian points. You will provide on‑site SME support during Level 2 through Level 5 Integrated Systems Testing (IST), troubleshooting complex field issues undergo live pressure. You will Implement robust code‑management, simulation, and cybersecurity practices aligned with ISA/IEC 62443 and owner standards.

The Senior Automation Software PLC Engineer – Critical Infrastructure will be self-directed on day-to-day work and independently performs most responsibilities. Will lead teams and projects or tasks of complex scope and broader programs. Will coordinate activities of other personnel. Assists in the development of policies and procedures.

This person will communicate and operate in line with organizational goals and values, as well as departmental objectives.

ESSENTIAL FUNCTIONS

PLC Software Development and Testing (65%)

• Design, program, and debug PLC logic for chilled‑water plants, HVAC, CRAH/CRACs, fan wall systems, and liquid cooling solutions

• Build reusable library objects and automated test harnesses; perform Factory Acceptance Testing (FAT) and Site Acceptance Testing (SAT)

• Execute Level 2 & 3 panel checkout and Level 4 functional testing; generate corrective patches during Level 5 IST.

Integration and Commissioning Support (20%)

• Collaborate with SCADA Engineer to develop tag maps and naming conventions; configure BACnet/IP, Modbus TCP, OPC‑UA, and SNMP interfaces

• Support OT network validation (VLAN segmentation, redundant rings) and coordinate with owner IT for secure connectivity

• Guide field & commissioning technicians on sequencing, test scripts, and punch‑list resolution.

Standards and Continuous Improvement (10%)

• Maintain and evolve STC global PLC code standards, cybersecurity hardening checklists, and simulation workflows

• Evaluate emerging PLC platforms and developer toolchains to improve build velocity and quality.

Mentorship and Reporting (5%)