Senior BMS Commissioning Engineer (Building Controls / OT) NI in Belfast

Hands-on senior commissioning engineer to lead the on-site integration work for a UK platform company building the operating system for critical infrastructure. BMS, SCADA, and building automation across NHS estates, data centres, and large commercial sites. You'll be the OKTO face on site during commissioning — configuring controllers, integrating systems, and making the platform actually work in the buildings we deploy into. Working under the Lead OT Engineer, with a clear path to grow as the function expands.

About OKTO: OKTO is a 33-year-old systems integration business pivoting to become a critical infrastructure platform company. We build CIDE-OS — an operating system for critical infrastructure estates — currently in reference deployment at a major NHS Trust. The platform synthesises operational state from BMS, SCADA, and clinical operational systems into a single honest surface for senior decision-makers. We are based in Lisburn, Northern Ireland, with active project work across the UK. We are a small team at the inflection point between integrator and platform company.

Why this role is genuinely interesting: If you've been commissioning BMS for a few years, you'll know most senior roles at large contractors involve doing more of the same on bigger projects. This is different. You'll be commissioning into a platform that is becoming a category, working alongside an experienced lead, with real ownership of how the work gets done. Small team, serious work, room to grow.

What you will do:

• Configure and commission BMS, SCADA, and building automation systems for CIDE-OS deployments.
• Integrate underlying estate systems with the CIDE-OS data fabric — BACnet/IP, Modbus, KNX, OPC, MQTT, REST APIs, and direct integrations as required.
• Work alongside client engineers, M&E consultants, and Tier-1 contractors during commissioning — the OKTO face on site for the technical work.
• Document configurations, integration decisions, and operational handovers to professional standards — the audit trail matters.
• Identify integration patterns that should be standardised at the platform level — feed insights back to the Lead OT Engineer.
• Mentor more junior engineers as the OT function grows.

Technical background we are looking for: 6+ years of hands-on experience configuring, commissioning, and integrating building systems in commercial-scale projects. Strong working knowledge of at least three of:

• Tridium (Niagara framework) — workbench-level configuration, drivers, integration.
• Schneider Electric BMS (EcoStruxure Building / StruxureWare / Andover) — configuration, point mapping, integration.
• KNX — system commissioning, ETS configuration, integration with BMS layers.
• BACnet/IP — point mapping, network configuration, troubleshooting at scale.
• Crestron, AMX, or similar AV control systems — useful background; not central, but the integration mindset translates.
• SCADA configuration and integration — particularly in critical environments.

Sector experience: Practical commissioning in commercial-scale estates: Trusts, large commercial buildings, data centres, pharmaceutical sites, university campuses, or industrial process facilities. Strong commercial-scale BMS commissioning experience translates well.

How you work:

• Hands-on and practical — you enjoy making systems actually work, not just designing them on paper.
• Methodical — you commission systematically, test thoroughly, and document as you go.
• Calm under pressure — commissioning windows are tight and things go wrong; the test is how you handle it.
• Honest about progress — you tell the truth about where the work is, including when it is behind.
• Client-facing without being sales-y — the senior engineers you work alongside on site are colleagues, not customers.

Working pattern: Based in either Northern Ireland or London, with regular travel between the two — typically Monday-to-Friday during active deployment phases, quieter weeks based at home. Travel and accommodation costs covered by OKTO. Be honest with yourself about whether that pattern fits your circumstances.

Compensation: Base salary: £55,000–£75,000 (NI-based), depending on experience. Share options available subject to performance and tenure. Contract alternative: 12-month fixed-term contract at £375–£475 per day (inside IR35), depending on experience. Travel and accommodation covered. Standard benefits package. We're not the highest-paying option — the larger BMS players and major contractors will pay more in base salary. What we offer is genuinely interesting work, exposure to a platform becoming a category, and the chance to grow with a small team.

How to apply: Send a CV and a short covering note to . The covering note matters more than the CV — tell us in plain English what you have built and commissioned, and what you have learned from a project that did not go to plan. We are looking for substance, not polish. First stage is a 30-minute call. Second stage is a practical technical discussion at our Lisburn workshop with the engineering team. Reasonable travel expenses for interview covered.