◆ JavaScript

Optimize JavaScript performance

This is real work, not a feature someone invented — it comes from real job ads and real questions people asked. Below are four ready AI prompts: get it done, make it easy for the next person to say yes to, work out the right move when you are stuck, and stop it coming back.

4prompts

The same task, four prompts

today's deadline · the next reviewer · the stuck moment · the pattern
AExecute — do the immediate taskProfile the 'renderProductList' function in the main product page component and report any…+
Profile the 'renderProductList' function in the main product page component and report any calls taking longer than 50ms.
when the reply comes backPush once: ask it to sharpen the weakest part, and to say what it assumed. Helpful?
BImprove — make it easier to acceptBefore we push the new dashboard to production, analyze the 'dataFetch' module. Focus on…+
Before we push the new dashboard to production, analyze the 'dataFetch' module. Focus on reducing its initial load time by at least 200ms and identify any memory leaks that might show up after an hour of continuous use.
when the reply comes backPush once: ask it to sharpen the weakest part, and to say what it assumed. Helpful?
CDecide — diagnose the stuck momentThe client just reported their analytics dashboard is freezing for a few seconds when applying…+
The client just reported that their analytics dashboard is freezing for a few seconds when they apply new filters.
The client just reported their analytics dashboard is freezing for a few seconds when applying new filters. I suspect it's a render-blocking script or an inefficient data transformation, but I can't tell if it's the backend response time or the frontend processing. I'm afraid of suggesting a fix that doesn't address the root cause, making it worse. What's the most likely diagnosis for this kind of intermittent UI freeze, and what's the best first step to pinpoint the exact bottleneck without impacting the live system?
when the reply comes backPush once: ask it to sharpen the weakest part, and to say what it assumed. Helpful?
DBecome — change the patternI'm constantly getting pulled into urgent performance fixes right before major releases, like…+
I keep getting pulled into urgent performance fixes right before major releases.
I'm constantly getting pulled into urgent performance fixes right before major releases, like the 'Black Friday' sale, because things only surface under load. This costs us credibility and delays deployments. What habit can I change to proactively identify and address performance bottlenecks earlier in the development cycle, perhaps by integrating performance testing into our daily workflow, so we're not scrambling at the last minute?
when the reply comes backPush once: ask it to sharpen the weakest part, and to say what it assumed. Helpful?

Questions people actually ask

honest answers, no sign-up

Every task here was seen in the real world. Someone doing the job named it, a real job ad asked for it, or a lot of people asked about it online.

If nothing real showed a task, it is not on the page. That is the whole rule.

They are the same job approached four ways, because what you need depends on where you are.

Get it done today. Make it easy for the next person to say yes to. Work out the right move when you are stuck. Learn the pattern so the job stops coming back.

For most of these jobs it can carry the heavy thinking - draft it, sort it, check it, rehearse it with you.

It cannot sit in your chair, take the blame when a number is wrong, or notice what nobody wrote down. Let it do the first 80%. Keep the last 20% that is truly yours.

No. Copy any prompt and paste it into the AI you already use. No account, no score, no wall in the way.

Any of them. The prompts describe the work rather than naming a product, so they are not tied to one assistant.

That is also why they keep working when you switch.

Change it freely. Every prompt is a starting line, not a rule.

Put in your real numbers, your real names and your real deadline. The more you make it yours, the better the answer comes back.

The tasks come from real job ads, published job data and the questions people ask in public forums.

The steps come from JavaScript's own documentation, with practitioner sources for the traps the manual does not mention.

Push once. Ask it to sharpen the weakest part and to say what it assumed.

Most wrong answers come from a missing detail rather than a bad prompt - tell it the thing it could not know.