List of free illustration stuff for developer👇🏽
If you're looking for all programming tools around illustration (not just free). Check this page List of illustration Programming Tools

Open Peeps, Hand-Drawn Illustration Library
Open Peeps is a hand-drawn illustration library to create scenes of people. You can use them in product illustration, marketing, comics, product states, user flows, personas, storyboarding, quinceañera invitations, or whatever you want! ⠀
Tag: asset, illustration

Open Doodles - Free sketchy illustrations
A library of sketchy illustrations of people free for personal and commercial use.
Tag: asset, illustration

Dribbble
Dribbble is an online community and service for the exhibition of artistic content. It works as a self-promotion and networking platform for graphic design, web design, illustration, photography, and other creative areas
Tag: design, web-design, illustration

designstripe
A constantly growing library from our Studio team, all completely customizable online
Tag: illustration, design, asset
1 illustration style Access to the Cheerful style only Full scene customization PNG, and JPG downloads