Hello Interview https://www.hellointerview.com/dashboard

Hello Interview Youtube Channel https://www.youtube.com/@hello_interview/videos

System Design School - System Design Primer https://systemdesignschool.io/problems/chatapp/solution

快速核心觀念影片 https://www.youtube.com/watch?v=s9Qh9fWeOAk

更完整的觀念影片 https://www.youtube.com/watch?v=F2FmTdLtb_4

Back-of-the-envelope Resource Estimation https://systemdesignschool.io/resource-estimator?dau=100000000&read_write_ratio=100:1&write_operations=10&data_retention=120&data_per_write_request=100&precision_mode=true