We had a problem.
Bonzai, one of our legacy products, was about to die. Not because customers stopped using it, they love it. Not because it stopped working, it was running fine.
It was going to die because Microsoft decided to kill the foundation it was built on. Yup one of those end of life things Microsoft does.
The Setup
Bonzai is at least 10 years old. It was designed for on-premise SharePoint, the kind where you have servers sitting in your own building, not hosted in the cloud. It's a collection of 26 web parts that make SharePoint better. Our customers have been using it for years..
Microsoft had other plans. They deprecated the APIs Bonzai relied on. The product was going to fall over in April 2026.
The Problem
Nobody on our team knew the codebase well enough to rewrite it. It was based on .NET code from the late early 2000’s. Some of my developers weren't even born when this code was written.
We got an estimate from a former developer: 86 weeks to rebuild. That's a year and a half. And if you've worked in tech, you know that's actually 2-3 years once reality sets in.
We didn't have that kind of time. And even if we did, what's the opportunity cost? What are you not building while you're stuck rebuilding legacy code?
The Challenge
I challenged my team: figure out how to rebuild Bonzai using AI. Modern code. Modern patterns. Modern languages. And do it fast.
My AI Builders team, Mikko, Akash, Rashdi, and Omar, were skeptical. Omar, my resident pessimist, straight up said, "I don't know if we can do this."
I pushed anyway. I was relentless. I told them: you have to figure it out. I just knew it could be done, at least theoretically.
The Result
One week later, they showed me progress. A couple of web parts were rebuilt. Then more. Then more.
By the end of three weeks, they had rebuilt 23 out of 26 web parts to work on the modern version of SharePoint.. Only the three most complicated ones were left, and they're working through those now.
We're five months ahead of the April 2026 deadline. Customers are already seeing Bonzai 2.0. They know how to upgrade. The product is saved.
What This Means
We didn't just save a product. We proved something I've been saying for months: AI can help you rebuild legacy software faster than anyone thinks possible.
Give a couple of smart problem solvers AI tools and a clear problem to solve, and they'll do in weeks what used to take a big team a year or more.
This is the hill I'm willing to die on: AI doesn't just rewrite the future of software. It keeps old software running. And it does it easier and faster than ever before.
If you've got legacy products sitting in your "too hard" pile, it might be time to take another look.
Kathy.
PS. Curious how we did it? Watch the video