Ot Solutions Architect

Southern Water; Worthing; Hybrid; GBP 70,000 - 110,000; Full time

Job summary

Southern Water invites an experienced OT Solutions Architect to lead secure, scalable OT designs across our processing and distribution networks. You will shape OT architectures that integrate with IT, ensure governance, and support safe operations across water and wastewater assets.

You will collaborate with engineering, IT, cybersecurity and external partners, align with IEC 62443, NIST and ISO 27001, and drive deployment across SCADA, PLC, DCS, HMI and historian environments.

Qualifications

• Experience in OT and ICS architecture across critical environments.
• Design OT solutions involving SCADA, PLC, DCS, RTU, HMI and historian.
• Knowledge of industrial protocols: OPC-UA, Modbus/TCP, DNP3, PROFINET, Ethernet/IP, BACnet.
• Experience designing secure OT networks with segmentation and Purdue Model.
• Strong OT cybersecurity knowledge: IEC 62443, NIST, ISO 27001.

Responsibilities

• Design OT architectures across SCADA, PLC, DCS, HMI, historian and industrial network environments.
• Develop integrated OT/IT solutions and defining data flows and system interfaces.
• Provide technical assurance and governance for OT designs and implementations.
• Support OT cybersecurity initiatives and ensuring alignment with standards such as IEC 62443, NIST and ISO 27001.
• Lead technical engagement with system integrators, vendors and operational stakeholders.
• Supporting deployment, testing, commissioning and migration activities across OT environments.

Skills

OT architecture

SCADA

PLC

DCS

RTU

HMI

OPC-UA

DNP3

Industrial networks

Cybersecurity

Job description

Closing Date

2026-12-01

Job Title: OT Solutions Architect

Location: Falmer or Durrington – Hybrid working (2 days a week)

Salary: depending on skills and experience

Help shape the future of operational technology at Southern Water.

We're looking for an experienced OT Solutions Architect to lead the design of secure, resilient and scalable Operational Technology (OT) solutions that support critical water and wastewater operations. This is an exciting opportunity to work at the intersection of industrial control systems, cybersecurity and digital transformation, helping to modernise essential infrastructure that serves millions of customers.

What will you be doing?

As an OT Solutions Architect, you'll be responsible for developing and governing OT architectures across our operational environments, ensuring solutions are secure, reliable and aligned with enterprise technology strategies. You'll work closely with engineering, operations, IT, cybersecurity teams and external partners to deliver innovative solutions that support safe and efficient operations.

Key responsibilities include:

• Designing OT architectures across SCADA, PLC, DCS, HMI, historian and industrial network environments.
• Developing integrated OT/IT solutions and defining data flows and system interfaces.
• Providing technical assurance and governance for OT designs and implementations.
• Supporting OT cybersecurity initiatives and ensuring alignment with standards such as IEC 62443, NIST and ISO 27001.
• Leading technical engagement with system integrators, vendors and operational stakeholders.
• Supporting deployment, testing, commissioning and migration activities across OT environments.

What are we looking for?

You’ll bring significant experience in Operational Technology and industrial control system architecture, with a deep understanding of complex operational environments.

We’re particularly interested in candidates with:

• Experience designing OT solutions involving SCADA, PLC, DCS, RTU, HMI and historian technologies.
• Knowledge of industrial communications protocols such as OPC-UA, Modbus/TCP, DNP3, PROFINET, Ethernet/IP and BACnet.
• Experience designing secure OT networks, including segmentation, firewalls and Purdue Model principles.
• Strong understanding of OT cybersecurity, including IEC 62443, NIST and ISO 27001 frameworks.
• Experience integrating OT environments with wider enterprise platforms, cloud or edge technologies.
• The ability to influence stakeholders and provide technical leadership across multidisciplinary teams.

Desirable

• TOGAF, SABSA, CISSP, GICSP or ISA/IEC 62443 certifications.
• Experience working within highly regulated or safety-critical industries such as water, energy, transport or pharmaceuticals.
• Exposure to digital twins, predictive maintenance or advanced analytics solutions.

Why join Southern Water?

This role offers the opportunity to play a key part in the modernisation and security of critical national infrastructure. You’ll work on complex and rewarding projects, collaborate with talented specialists and help shape the future of operational technology across Southern Water.