Certificate Manager B2B project (2011-2014)
The first and the second versions of Comodo Certificate Manager (now — Sectigo)
I conducted two successful iterations of the redesign of this project. Step by step to do not irritate existing users too much. Because sometimes UX Designer should avoid increase usability in a short period of time. Every redesign act is a big stress for the users. They can hide (don't use the app), run (unsubscribing) or attack (by leaving negative reviews, complaining).
What have I learned from this project?

I've put myself on the user's place. I was trying walking in admin's shoes. Any change was crucial. The product was number one in the company financially. I was digging into the data and my effort was successful.