The Last Two People Who Understand It: A CTO's Playbook for Modernizing Legacy .NET Before the Knowledge Is Gone

By R. B. Merrick

Microsoft will never send you a deadline. Your people will.

There is no end-of-life date for .NET Framework. No cliff, no forced migration, nothing waiting in your inbox. Your system will keep running for years.

That is exactly the problem. The real deadline is set by people, not vendors - and it falls on the day the last person who remembers why the system works walks out the door. After that, no budget buys the knowledge back.

Most writing on legacy modernization is aimed at developers: migration patterns, refactoring techniques, architectural strategy. This book is for the person who has to fund the work, sequence it, and survive it - and who keeps losing the argument while being right.

InsideThe three clocks running on your estate, and why the one that hurts first is never the one you're watchingWhat standing still actually costs - the four taxes that never appear on a P&LHow to translate an architecture problem into the language a CFO acts on, and the one-page business case that gets a yesMigrate, rebuild, replace or retire - a decision model for routing each system to the right fateHow to replace a system piece by piece without ever stopping the businessAn honest account of where AI genuinely helps and where it confidently failsA practical program for getting the reasoning out of your experts' heads while you still have experts

Written from inside the problem. The author helped build the call-center platform described in this book fifteen years ago, and is now helping replace it - which makes him one of the two people the title refers to. The war stories are first-hand, including the expensive mistakes.

The working documents from the book - business case, system inventory, rollback plan, why-session guide and more - are free to download at r4b2c.com/playbook

• Format: Paperback
• Language: English
• ISBN: B0HDK6PN5Q
• ISBN13: 9798191014265
• Release Date: August 2026
• Publisher: Independently published
• Length: 136 Pages
• Weight: 0.43 lbs.
• Dimensions: 9.0" x 0.3" x 6.0"