* Determine exactly how moving to a new framework will benefit your users. If it doesn’t, why are you doing it? It is going to be a lot of hard work and your users will not care you’re on a new framework.
* evaluate if Angular really is the right choice to upgrade to * if it is, do not mix the code in one repo. Use two repos.
* Migrate route by route, starting with lowest impact pages first. When user clicks on the route served by the new angular page it will point to the new app
* to support this, you’ll need to build out foundational modules critical for the switching to happen, e.g. auth, common header, footer, menus etc
* how the switch happens between routes is up to how your app is served. You will need to configure the domain to stay the same between serving the different apps.
* update your deployment and testing strategies to account for two apps going out instead of one.
* we took a bell curve approach, lowest impact routes first, then peaked with critical routes, then back to less and less important pages. This allowed a gradual ramp up to work out the kinks but at some point you will need to get your most important stuff moved over so you’re not building two systems.
* get buy-in from stakeholders that this migration is going to add value for users. Get them excited so you are working together to get it all moved over.
* allocate x% of Dev time to the transition.
* agree on a date for each route and for the full transition so work can be prioritized.
I’m sure there’s loads of blogs with more specifics. Just wanted to share my experience at a high level.