Architecture Decision Records (ADRs) are a way to document important architectural decisions in a structured manner. They help in maintaining a record of the rationale behind decisions, alternatives considered, and the implications of those decisions. For more information see adr.github.io.

A modular monolith, or "modulith", is an architectural style where the application is structured into distinct modules within a single deployable unit. Each module encapsulates specific functionality and can interact with other modules through well-defined interfaces. This approach combines the benefits of modularity with the simplicity of a monolithic deployment. For more information see the Spring Modulith blog post or this german Entwickler.de article about moduliths.