OT Contractor (Columbus, IN)

Role:: OT Contractor

Location :: Columbus, IN 47201

Duration :: 6+ Months (Possible extension)

Job Description:

We are seeking an experienced OT Contractor to support critical infrastructure and cybersecurity initiatives at our Columbus, IN site. The ideal candidate will have a strong background in OT/ICS security, system installation, configuration, and maintenance. This role requires a hands-on professional who can take specifications from the internal team and deliver end-to-end implementation, testing, and ongoing operations.

Key Responsibilities

• Install, configure, and maintain double firewall/DMZ architecture.
• Set up OT systems, execute FAT/SAT tests, generate reports, and monitor performance.
• Segregate Industrial Control Systems (ICS) into dedicated security zones.
• Implement Endpoint Protection, centralized management, and real-time scanning.
• Ensure secure ICS protocols and detect rogue/malicious IP addresses.
• Maintain minimal customization-preserve vanilla setups and configurations.
• Upgrade OT machines to the latest operating systems.
• Develop and enforce tailored cybersecurity policies for ICS environments.
• Synchronize time with accurate/reliable sources (GPS, Galileo, RADIO, etc.).
• Implement Application Whitelisting (low enforcement mode).
• Ensure segregation between process control networks (DCS/PLCs) and Safety Instrumented Systems (SIS).

Risk Mitigation & Security Responsibilities

The role will also require addressing and mitigating risks across OT environments, including but not limited to:

• Policy & Governance: Develop third-party, account management, and access control policies.
• Patch & Vulnerability Management: Create patch management procedures, perform vulnerability assessments, and conduct penetration testing.
• Business Continuity & Disaster Recovery: Develop BCP/DRP policies, backup strategies, and recovery procedures.
• Cryptography & Certificates: Implement lifecycle management and cryptographic protections for ICS.
• Network Segmentation & Monitoring: Ensure proper DMZ setup, firewall IDS/IPS, and SIEM integration for real-time monitoring.
• Incident Response: Build and test incident response plans, conduct drills, and align with corporate cybersecurity.
• Audit & Logging: Establish audit event records, log monitoring, and audit protection mechanisms.
• Asset & Inventory Management: Maintain updated OT/IT asset inventories including application versions.
• System Security Hardening: Deploy antivirus, whitelisting, and security controls to safeguard ICS/DCS/HMI systems.

Qualifications

• Proven experience in OT/ICS cybersecurity, firewalls, and DMZ implementation.
• Strong understanding of DCS, PLC, HMI, SIS, and industrial environments.
• Hands-on experience with Endpoint Protection, patching, vulnerability assessment, and penetration testing.
• Knowledge of SIEM tools, IDS/IPS, cryptography, and network segmentation.
• Experience in developing and executing cybersecurity policies, incident response, and disaster recovery.

Ability to work independently and deliver within tight timelines.

Dexian is a leading provider of staffing, IT, and workforce solutions with over 12,000 employees and 70 locations worldwide. As one of the largest IT staffing companies and the 2nd largest minority-owned staffing company in the U.S., Dexian was formed in 2023 through the merger of DISYS and Signature Consultants. Combining the best elements of its core companies, Dexian's platform connects talent, technology, and organizations to produce game-changing results that help everyone achieve their ambitions and goals.

Dexian's brands include Dexian DISYS, Dexian Signature Consultants, Dexian Government Solutions, Dexian Talent Development and Dexian IT Solutions. Visit https://dexian.com/ to learn more.

Dexian is an Equal Opportunity Employer that recruits and hires qualified candidates without regard to race, religion, sex, sexual orientation, gender identity, age, national origin, ancestry, citizenship, disability, or veteran status.