We've just completed another successful Sitecore upgrade! We often update our client's websites to newer versions of Sitecore and it has to be said, it's getting to be no walk in the park. Sitecore is enterprise software and this becomes clear during upgrades. Also, search engines return very few "lessons learned" pages as they have not yet been published. That is why upgrades often require you to go back to old-school and "slog it out".

Some of the upgrade details are:

• Upgrade Sitecore 8.2 Initial Release to Sitecore 9.2 Initial Release
• Web forms upgraded from code behind to MVC
• WFFM upgrade to Sitecore Forms
• Configuration files upgraded
• Custom DLL's rebuilt to support Sitecore 9.2
• Convert from Lucene indexing to Solr
• Support existing Sitecore - Salesforce - Pardot integration with S4S 
• Implemented a custom save action for Sitecore forms to send emails
• Much more 

There are a lot of moving parts in that mix but the project went well and the parties were pleased with the outcome. An increase in site performance was the key deliverable.

So this post was more of a cry on the shoulder than information for developers. If you are looking to upgrade Sitecore, we strongly recommend using a company that has already been through the process (with your version), and don't expect they will be able to complete the work in a few hours.