Estimation prerequisites for Sitecore Migration and upgrade

 When we planning any sitecore upgrade from lower version such sitecore 8.0+ to sitecore 10+. It is always recommended to understand the dependencies , integration touch points and library.

• .Net framework vs .Net core any nuget /assembly/library/dll
• Solr
• Active Directory
• SQL server version
• IIS
• Federated Login Identity
• Asp.net mvc if it is mvc project
• Decide XM vs XP
• Mongo DB database migration to XConnect
• Azure Kubernetes require Sitecore v10.3.0

Sitecore Compatability table- XP|XM

https://support.sitecore.com/kb?id=kb_article_view&sysparm_article=KB0087164

Sitecore Solr Compatability table

https://support.sitecore.com/kb?id=kb_article_view&sysparm_article=KB0227897

Sitecore MongoDb Compatability table

https://support.sitecore.com/kb?id=kb_article_view&sysparm_article=KB0633863