A growing clean-energy engineering business is looking for a hands-on Senior PLC Software Engineer to support the development of next-generation ammonia cracking systems.

This role will focus on developing and implementing PLC-based control systems as the business continues to transition from prototype into scalable, deployable products. You’ll be working across the full lifecycle from software design through to real-world commissioning playing a key role in ensuring systems operate reliably in live environments.

This is a technical expert role, suited to someone who enjoys owning problems, improving development processes, and working closely with physical systems.

Senior PLC Software Engineer

Cranleigh, Surrey (Hybrid)

Permanent, Full-time

Salary: £. Competitive + Benefits:

Bonus scheme, Private healthcare, Share Options, Pension contribution, 25 days holiday + bank holidays, Flexible hours, Life assurance

What you’ll be doing

• Designing and developing PLC software for ammonia cracking systems.
• Programming PLCs (Siemens S7 / TIA Portal preferred, others considered).
• Working within an existing system architecture, with increasing input over time.
• Defining and improving software development processes and standards.
• Producing structured, maintainable code (IEC 61131-3).
• Supporting software verification and validation (including simulation where applicable).
• Integrating PLC systems with wider control architecture (HMI, SCADA, instrumentation).
• Supporting and leading commissioning activities, fault finding and debugging on live systems.
• Working closely with multidisciplinary teams across mechanical, electrical and systems engineering.
• Supporting data acquisition and system connectivity where required.

What we’re looking for

• Proven experience in industrial automation within Chemical processing or Manufacturing environments.
• Strong PLC programming experience (Siemens S7 ideal, others considered)
• Experience across the full lifecycle: design, development, testing and commissioning
• Strong fault finding and on-site debugging capability
• Experience working on complex engineered or process systems
• Ability to bring structure and rigour to software development processes

Desirable:

• Experience with simulation or software verification environments.
• Exposure to process systems, energy systems or similar technologies.
• Understanding of industrial communication protocols.

Why apply

• Work on cutting-edge hydrogen and ammonia energy technology.
• Be part of scaling a novel technology from prototype to commercial deployment.
• High-impact, hands-on engineering role.
• Flexible hybrid working with real autonomy.
• Opportunity to shape how control systems are developed as the business grows.

To apply or find out more, drop me a message or contact me at lewis@cranleighstem.co.uk