This is how I save 20 hours on user research π€―
1. Describe your business and target audience
2. Wait for 10 seconds
3. Get a detailed description of your ideal customer
And yes, it's free β¬οΈ
Don't demo software. You will get no useful feedback from a demo. Instead, sit your users/customers down in front of a computer and watch them use it. Ask questions. Do that frequently as you work. If an engineer is sitting in front of the computer, you learn essentially nothing.
By far the strangest TypeScript trick I've ever come across is the Loose Autocomplete trick.
No idea who discovered this, but it's become widely used by OSS wizards.
It's now even used by React's types to type attributes like aria-role.