The Day I Learned to Respect Database Indexes (The Hard Way)

In 2021, I graduated from my university and joined a startup as its first employee. That time, I learned a lot of things. I picked up the full stack from scratch, Flutter, Node.js, MongoDB, all of it. I learned fast and I was building things on my own within a few months. But there was one thing nobody told me to learn, and I never thought about it myself, database optimization. The Launch Was Three Days Away The company got a big project, and we worked on it for months. One day, we found out the launch was only three days away. The app had three levels of users. The lowest level users were added by us directly, and as part of that work, I uploaded more than 4 lakh user accounts into the database before the launch. The plan for the event was simple. On launch day, the mid level users would sign up on their own, live, in front of everyone. The Server Started Crashing Launch day came. The mid level users started registering. After about 50 people signed up, th