In late 2018 the React team announced the introduction of Hooks – a new API that enables the use of state and lifecycle methods in functional components. The Suspense API is in its early days, but will soon be used for data fetching, and the combination of the two will essentially make class components redundant. This raises the question - how does React do that? How does it make the setState mechanism and lifecycle methods accessible without inheritance from React Component? And what does it actually mean that Suspense “suspends rendering”? Time to dive into library internals, again! Let’s look at React’s source code and figure out what’s going on under the hood here.