SWR, Webhooks, useState Deep Dive, and a Few Things Worth Cementing

A session that revisits some fundamentals with fresh eyes and adds a couple of genuinely useful concepts on top. The useState explanation here is the clearest it's been — worth reading carefully. React SWR — Show Old Data, Fetch New Data, Nobody Waits SWR stands for Stale-While-Revalidate — a caching strategy that shows you whatever data it already has while quietly fetching fresh data in the background. Here's what makes it worth knowing: You give it a key (usually the URL) and a fetcher function (your actual network call). It handles the rest — caching, revalidating, deduplication. If ten components all need the same data, SWR doesn't make ten requests. It makes one and shares the result across all of them. It also re-fetches automatically when you re-focus the window — so if a user switches tabs and comes back, they always see fresh data without you writing any logic for it. const { data, error, isLoading } = useSWR('/api/user', fetcher); Three things back — your data, any error, an