What notations do you work with in practice?

In practice, I most often use UML (Unified Modeling Language) for visualizing architecture and processes. I apply class diagrams, sequence diagrams, use case diagrams, and activity diagrams in UML. I have also worked with BPMN (Business Process Model and Notation) to describe business processes, which helps align requirements with the client and the team. Sometimes, I use ER diagrams for database modeling.