What is Cold Start?
The delay when a serverless function starts up after being idle. It affects the first request after a quiet period but not subsequent ones.
1st 800 ms · next 30 ms
A cold start happens when a function...
Write it in your own words in the app.
In real work
This webhook has a cold start problem. Move heavy initialization outside the handler to shorten startup time.
In the illustration
The engine sits cold; the first request pulls the cord and waits while the gauge climbs through warm-up, then the next two requests are answered at once by the running engine.
Profile the checkout API on your deploy platform for cold start latency. Report p95 for the first request after idle and propose what to keep warm.
Try it now
The fastest way to learn a word is to use it. Open this line in the agent you already work in and watch what it does. Change the tool to the one you use.
Go further
01Practice
Make it stick
One term a day, a short quiz, and sentence practice that checks your own words.
02Verify
Prove you know it
Pass the quiz and keep it in a Skills Wallet you can share with anyone who needs proof.
03Career
Find the work that uses it
See which roles lean on this vocabulary, and what they pay in year one.
Learn the next term tomorrow.
Google gives a definition. Prompthaus pairs each term with how it shows up in standups, PRs, prompts, and design reviews. Then it quizzes you until the word sticks. One term a day on iPhone.
