A click response and some background preprocessing shouldn’t compete as equals on the JavaScript main thread.

scheduler.postTask() lets you express that directly with task priorities. It’s a very interesting API, although browser support still isn’t complete.

Object identity is one of those React concepts I think we hide too much.

Dependencies are compared with "Object.is", memoization relies heavily on stable references, and external-store snapshots do too.

That’s where structural sharing becomes useful: unchanged branches can keep their identity.

Can you define what debounce and throttle are really solving?

They’re usually taught as timing utilities, but the deeper problem is backpressure: the UI can produce work faster than the system can consume it.

Debouncing, throttling, buffering and coalescing are different ways to handle that.

With a search input in React, how do you guarantee you’re displaying the result for the latest query?

Cancelling the previous request is one solution. But cancellation and relevance are different problems. Even if you can’t cancel the work, you can still ignore a result that became obsolete.

Do you know what tearing is in React?

When React reads from an external store, the UI needs to reflect one consistent version of it. If the store changes during a render, different parts could otherwise be built from different snapshots.

That inconsistency is called tearing.

If you’ve ever added a constraint to a huge production table with millions of rows, you know the expensive part is usually checking the old data.

PostgreSQL NOT VALID lets you protect new writes now, then validate the existing rows later, without making the initial migration wait on that full scan.

Do you know the difference between <Component /> and {Component()} ?

Both can render the exact same UI.

But only one tells React “this is a component.” The other just executes a function inside the current render, which changes how React understands the tree itself.

One thing that really struck me about the Navigation API is just how much SPAs have influenced the web platform.

Look at this and tell me you don’t recognize the routing model SPA frameworks have been using for years:

This component will re-render all the time.

Yes, it has been memoized, but children is a prop too. And here, children contains <span>hello</span>, which creates a new React element object on every render.

memo() does a shallow comparison, sees a new children value, and re-renders the component.

AI’s share of software spend has multiplied by 5 in less than two years. Your first thought might be: “AI will replace software!”

I think the opposite.

AI is lowering the bar for what’s worth building. Projects that made no economic sense are becoming feasible. We may build much more software.

Adjusting child widths based on sibling count used to take a few tricks. And don’t even mention staggered animations.

Well, CSS can now handle both directly:

.item {
width: calc(100% / sibling-count());
animation-delay: calc(sibling-index() * 100ms);
}

About time!