DDD is a software development approach that focuses on modeling the problem domain and building the software system around that model, to create more effective and maintainable software.
CleanArchitecture
https://github.com/kgrzybek/modular-monolith-with-ddd dddsample-core
ddd-by-examples python-ddd
ddd-playground php-ddd-example
ddd-playground Domain Driven Design (martin fowler)
domain-driven-design-ddd (geeksforgeeks) Youtube