Lead OT/IT Architecture for Critical Infrastructure

Southern Water; England; On-site; GBP 85,000 - 120,000; Full time

Job summary

Southern Water is seeking an experienced Lead Architect to drive the NIS programme, acting as the architectural authority for OT, IT, data, security and integration. You will define roadmaps, govern design decisions and ensure enterprise standards are met across a large transformation initiative.

You will lead governance, review critical designs, manage dependencies and engage stakeholders to align technology with business outcomes within regulated infrastructure environments.

Qualifications

• Significant experience designing and governing OT and industrial control system environments.
• Strong knowledge of SCADA, PLC, DCS, RTU, HMI and historian technologies.
• Experience with OT networking, segmentation, firewalls and Purdue Model principles.
• Understanding of industrial protocols such as OPC-UA, Modbus/TCP, DNP3, PROFINET and Ethernet/IP.
• Knowledge of OT cyber security standards including IEC 62443, NIST, ISO 27001 and NIS requirements.
• Experience integrating OT with enterprise IT, cloud, data and monitoring solutions.
• Proven leadership of architecture across complex programmes or transformations.
• Excellent stakeholder engagement, governance and decision-making skills.

Responsibilities

• Lead architecture across a complex, business-critical programme.
• Define and maintain the end-to-end architecture roadmap and key design decisions.
• Ensure alignment across OT, IT, security, data, and technology domains.
• Establish and chair architecture governance and design assurance activities.
• Review and challenge designs from internal teams, system integrators, and third-party vendors.
• Identify and manage architectural risks, dependencies, and cross-programme impacts.
• Work with programme leadership to align technology decisions with business outcomes.
• Act as the primary architectural advisor for stakeholders across the programme.

Skills

OT Architecture

Industrial Control Systems

SCADA/PLC/DCS

OPC-UA

Industrial Networking

Cyber Security Standards

Stakeholder Engagement

Governance

Purdue Model

OT-IT integration

Job description

Southern Water is seeking an experienced Lead Architect to drive the NIS programme, acting as the architectural authority for OT, IT, data, security and integration. You will define roadmaps, govern design decisions and ensure enterprise standards are met across a large transformation initiative.

You will lead governance, review critical designs, manage dependencies and engage stakeholders to align technology with business outcomes within regulated infrastructure environments.