React + Python + Django is an effective software stack for building modern web applications. React is a JavaScript library used for building user interfaces, Python is a powerful programming language, and Django is a web framework for Python. Together, these three technologies provide an efficient and powerful solution for developing modern web applications. React is used for creating interactive user interfaces, and Python is used for writing the business logic of the web application. Django is the glue that ties everything together, providing a framework for creating web pages, managing databases, and handling user authentication. By using these three tools, developers can create robust, dynamic, and secure web applications in a fraction of the time it would take with other software stacks.