I'm Pieter Leek
Industrial Systems Engineer | OT/IT Systems & Integration
I quickly see how a system works, where it's vulnerable, and what needs to happen — whether you're in crisis or want to stay out of one.
OT/IT Systems • Industrial Networking • System Integration • 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 can design the architecture and then go on-site to make it work. I don't hand off to someone else when it gets technical.
Industrial Networks
Your machines and systems are not communicating properly, or you cannot figure out why the connection keeps dropping. I set up or fix industrial networks — VLANs, segmentation, firewall rules, and the connection between shop floor, office network and cloud.
System Integration
Your data is stuck on the machine. I make sure it gets where you need it — historian, dashboard or cloud — using OPC UA, MQTT or Modbus.
Troubleshooting
Something is not working and nobody knows why. I find out, and I fix it — during commissioning, in production, or anywhere in between.
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.
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.
That means I can move across the full stack: from sensors and industrial networks to software architecture and cloud connectivity. I don't get lost when a problem crosses a boundary, because I know what's on both sides.
I work with end users who need a problem solved fast, and with machine builders and system integrators who need someone experienced on-site when their own team is not enough.
I don't need a long ramp-up. I can read a system, find the weak point, and act — whether that's in the network, the software layer, the integration, or somewhere in between.
Reference Work
Designing Defensible Industrial Systems
To validate how I think about industrial architecture, I designed and built a working reference implementation of a defensible OT/IT system — from field sensors to cloud, following IEC 62443 zone segmentation, Zero Trust identity, NIS2 compliance readiness, and ISA-95 data modeling.
This is not a simulation. Zone 1 and Zone 2 are built and operational — ESP32 sensors with mTLS certificate identity, a hardened MQTT broker, NTP as a security control, ISA-95 namespace enforcement, and an Ignition SCADA node. All containerized, version-pinned, and declaratively managed in Git.
A six-part video demonstration series is in production, documenting each architectural layer under simulated failure conditions. The full technical paper is available below.
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.