On a small project I used sequence diagrams to document a custom Api/data flow, so that another team (different company) had a reference for implementing the cl

On a small project I used sequence diagrams to document a custom Api/data flow, so that another team (different company) had a reference for implementing the client to my (bespoke) JSON/REST server. I frequently draw simplified architecture and data/entity diagrams that tend to be "mostly" UML. Generally on a whiteboard while discussing design/architecture - rarely do they end up as permanent artifacts/documentation.