I got frustrated seeing how system design questions differ from the real world, and how big tech companies foster a scalability-first mindset across the industry, while cost-efficiency and critical thinking about real product requirements are much more important.

I've checked Bitly public numbers and typical URL shortener interview question requirements. And I've benchmarked a simple implementation as much as possible across different hardware. My obscure NAS already handles 2540 writes/sec. The PostgreSQL setup on AWS does 15900. Both have 3 billion pre-filled rows. While the interview asks for 1160, the real systems have only 93 writes/s.