Senior Automation Software PLC Engineer - Critical Infrastructure

Overview

Senior Automation Software PLC Engineer - Critical Infrastructure at Smart Tech Contracting (STC) leads high-availability PLC systems and Level 2–5 commissioning for hyperscale and colocation data-center campuses. This hands-on, high-impact engineering role is 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 10MW to 200MW+. 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 TierIII/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 Level2 through Level5 Integrated Systems Testing (IST), troubleshooting complex field issues under 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 and independently perform 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.

• 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 Level2 & 3 panel checkout and Level4 functional testing; generate corrective patches during Level5 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 tool chains to improve build velocity and quality
• Mentorship and Reporting (5%)
  • Mentor junior programmers and apprentices; deliver knowledge‑transfer workshops for owner operations teams
  • Manage team issues and KPI dashboards for internal and client reporting and continuous improvement

Completion of Assigned Tasks and Deliverables on Time and on Budget

Performs Other Related Duties as Assigned

POSITION REQUIREMENTS (ADVANCED LEVEL FOR ALL THE FOLLOWING)

• Technical Mastery: 10+ yrs hands‑on programming with Allen‑Bradley Control Logix/Compact Logix
• Application experience:
  Demonstrated HVAC and / or process systems including chilled water plants and…