I remember a few early projects that revolved around SP, but one that stands out as "special" was using the SOAP APIs to update a WordPress site. It was a special hell, every hour it would fetch any updates, and push them to the specific WP content-type (iirc - content-types might not have existed yet - this was 2008).

The reason for this, IT had contracted for a content management system from a Microsoft shop, because the CIO was a former Accenture/Avanade consultant. But the brochure-ware website had already been contracted to some random NYC-based web firm, but the CIO didn't want multiple usernames/passwords, so after the WordPress site hand been build, they hired the SharePoint consultants to build out the CMS that the employees would use, but it still didn't hook up to wordpress, so then it became another contractor's job (me) to join the two.

I had worked on Word Press, I even had a few decently popular plugins, but I had never seen the absolute hellscape that was SharePoint before. I wrote a codegen tool that would read the WSDL and create a library with all the classes and calls needed to use it without any SharePoint experience, and wrote some simple ETLs for the handful of "buckets". It was a 2-3 month long journey, but those libraries and my code are still in place today, where they still use wordpress for front-end, and sharepoint as backend (or at least did in 2022 still, the last I talked to anyone still working there).