Shame I can only give this 5 stars, would love to give it more🎉.
I've been through the transition from a Microsoft shop to an open source shop and it wasn't easy.
I feel the way it was handled offered infinite opportunities to have been done better. It wasn't really explained why we were doing it, what the benefits would be, long or short term. At the time it felt like a kick in the teeth for those of us who had the DBs ticking along happily like a Japanese performance engine. It also felt like the CTO/CIO were extreme anti-Microsoft people.
In hindsight it makes sense even if replacing SQL Server with MongoDB seems even worse now than it did originally. Had the choice been Postgres it would have made more sense.
If you are the instigator of massive change then a lot of communication is necessary. Not everyone can get on board and that's sad but a harsh reality. But, failure to communicate means that you risk losing talent that could smooth the path to success. Certainly a lot of problems were foreseen and dismissed with more ego than wisdom. The change was also extremely expensive. Not sure what ROI was achieved or even if it has been achieved.