CollabCodeTech/backend-challenges ? reverse-engineered prompt

Build me a simple public site that lists backend coding challenges from open source job tests around the world.

I want people to be able to browse the challenges, search by company or stack, and quickly open the original challenge link. Please show the company name, country, stack, and a clear link to the test, and make it easy to contribute new open source challenges too. Keep it clean and readable, like a useful directory people can skim fast. If you need to look up current docs or best practices for the tools, go ahead and do that.