I'm Pieter Leek
Industrial Systems Architect | OT/IT Integration · Custom Middleware · Solving Complex Legacy Puzzles
I get excited about technical and organisational challenges that others would rather avoid. Often it involves systems that don't talk to each other, stuck integrations, or legacy environments that nobody fully understands anymore. I step in, map the situation quickly, and get things moving again.
OT/IT Systems • Custom Middleware • Complex System Diagnosis • On-Site Worldwide
Technical Services
Hands-on technical expertise at the intersection of OT and IT — on-site, worldwide.
OT & IT — One System
Your IT department and your people on the floor speak a different language. I understand both sides and make sure the technology and the communication align. I design the architecture and go on-site to make it work. I don't hand off to someone else when it gets technical — and I don't leave until it does.
Custom Middleware & Connectors
Your machines and systems don't talk to each other — or to anything above them. I build the software layer that connects them: protocol translators, edge data services, API wrappers, and message pipelines. Whether it's MODBUS, OPC-UA, MQTT, or a proprietary interface — I make it flow.
System Integration
Your data is stuck on the machine. I make sure it gets where you need it — historian, dashboard, MES, ERP, or cloud — using OPC-UA, MQTT, Ignition, or custom connectors built for your specific situation.
Complex System Diagnosis
Something keeps breaking and nobody can pin down why — or worse, everyone has a theory and the fix never holds. I read the system as a whole. Network, control, software, integration, and the way people are actually using it — usually the cause sits across two of those, which is why nobody found it. I trace it, fix it, and write down what was actually wrong so it doesn't come back.
Go-Live Support
Go-live coming up and not enough hands on deck? I step in as an experienced technical resource — on-site, up to speed quickly, and ready to work across the full stack. Relevant for: port & terminal equipment, machine builders, system integrators delivering into Southeast Asia or the Middle East.
Python
JavaScript
AWS
Azure
CCNA
IoT
Linux
About
OT and IT are not two separate worlds to me. They are one system that needs to work together.
The bigger picture. Instead of just looking at symptoms, I look for the root of the problem. I prefer working from the main lines rather than drowning in micromanagement. That creates the clarity and overview needed to make decisions and get things done.
A broad toolkit. My background is deliberately broad. I've built production environments from hardware sensor to cloud dashboard and connected ERP systems to factories on the other side of the world. Whether it's industrial protocols that were never meant to work together or guiding a team through a change process — I use whatever is needed at that moment to solve it.
Technology and the human side. A system only works when the people around it do too. I switch just as easily between software stacks and the people on the shop floor or in the boardroom. Not by playing a role, but through genuine interest in how the environment actually works.
Short, intense, and results-driven. My strength lies in project-based engagements, usually up to 12 months. I come in to solve a problem, build what's needed, secure the quality, and hand it back over cleanly.
Based in the Netherlands. Available worldwide for challenging missions.
Reference Work
Building a Connected Industrial System
To validate how I think about industrial integration today, I designed and built a working reference implementation of a connected OT/IT stack — from field sensors to cloud, following ISA-95 data modeling and IEC 62443 zone structure.
This is not a simulation. ESP32 sensors publish over MQTT with certificate-based identity, a hardened broker handles routing, an ISA-95 namespace enforces data structure, and Ignition SCADA consumes and visualizes the result. All containerized, version-pinned, and declaratively managed in Git.
A six-part video series is in production, documenting each integration layer under real conditions.
The architecture reflects how I've been delivering industrial systems since 2004 — control systems for energy infrastructure, remote monitoring for medical equipment, international e-commerce integrations across legacy backends. This reference build is the current expression of that work.
Contact
Need someone who knows both sides? Mail me at pieter@qman.io or send a message on LinkedIn.
From wiring to code, and everything in between.