This is a PR for the 99tech coding tasks.
Even though I applied as a frontend developer, I wanted to do the fullstack code challenge as i have experience in both frontend and backend, so I made a minimal but complete project to show the result of the function, UI, and use mockup api in the backend folder to show the result of the function following the problem requirement as I combine the spec together to make a complete project. If you wanted just to see the minimal solution to each problem you can check the docs folder for each problem and see the readme.md file. If you wanted to view the full project you can check the frontend and backend folder and run the project locally by using the run.sh. I also grouped problem1-4 together as they are the same as they have same requirement.
Docs organization: