I am not sure if that is really great idea for every ‘large’ app. Yeah, micro applications are cool. But modules are cool too. When you don’t want your codebase to be monolithic you can use either micro-apps or modules.
For example, we use ng2 as framework and webpack as bundler. Angular provides styling isolation; ng2+webpack provides code splitting. So we can easily choose to share code or not. Yeah, it can be a bit hard & uncontrolled sometime, but almost 95% of time we got benefits of module architecture.
I see no real benefits from micro-apps except support of legacy & new code together without problems. That works pretty well. But if you don’t have legacy then you probably don’t need such complex solution.
Also, iframes has one really bad defect. Just think about showing tooltips and popups.
