TypeScript as a defense
TLDR If you have no time for TDD, you should at least use types.
React with RxJS
When we started the migration to React we faced an interesting problem. Most of the resources explained data structures in React on very simple examples. Our data model was far more complex. Also, we had to combine React with other stacks, like GridLayout (based on jQuery) and leave the ability to shift to any other codebase in the future.
TLDR Documenting massive redux models with asynchronous actions can be simplified by using old good Graphviz and few comments in the code.