We made a Bot Used by 180k Students for 3 Centuries’ Worth of Time

TLDR: I made an open-source Discord bot that displays real-time rankings 🧗of the time students have truly spent in our StudyStream Discord study server, for free.

The Non-Technical Backstory

A person usually focuses much better if watched by others.

— Zack Light

I coined this theory of mine the prison effect of studying 🔒. Based on it, I decided to search for online study rooms when my university shut down its libraries due to COVID around March 2020. (My backup option was to go back to as a StudyTuber.)

Luckily, I found a community on Discord with about 1k students 🤩. I became hooked by how the leaderboard inside the server has gamified studying 🎮.

Games are the only force in the known universe that can get people to take actions against their self-interest, in a predictable way, without using force.”

— Gabe Zichermann

The leaderboard motivated me and my peers to study non-stop, seriously. Since there are many types of rankings like all-time, monthly, weekly, daily, hours, etc., and streaks, it’s easy to set a goal suitable for oneself. Personally, I was mostly focused on the longer-term: monthly and all-time. I have strived to be within the monthly top 10 and all-time top 3.


Moreover, it’s extremely motivating to see friends work so hard to try to catch up with you ⚔️. Admittedly though, I do have friends addicted to online studying so much that they sleep inhumanly little every day 🤯…

My semester went so well that I secured my full-time job before my last winter vacation. To give back to this symbiotic community 👼, I decided to spend my winter vacation coding an open-source Discord bot capable of displaying real-time rankings of students’ study time on the server, for free.

The Technical Process

I initially did an elaborate SQL database design.


Very elaborate just like the SQL design homework I have done

In reflection, the final database we have is way simpler. For example, to store channel names and channel IDs, I ended up using a simple HJSON file that allows our non-technical mods to edit easily. Storing some rarely-changed data like this in SQL is simply counter-productive for us.

The biggest challenge, and the reason why no other real-time time-ranking bot exists (AFAIK) is that we have too many students to sort every student’s study time for every display of the leaderboard 😰. One way is to sort all the 170k students and refresh the leaderboard periodically, but it was hardly scalable and required a waiting period horrible for UX.


So I created handlers that log the times when students join study rooms and, when they leave, add the amount of elapsed time to our database. I used a skip-list for real-time ranking for logarithmically complex operations. (It’s a marvelous albeit so-called “advanced” probabilistic data structure.)


Based on this idea, I started to implement, test, and debug the whole program. The code is well-documented here 😇. (Many of our and all of my projects are open-source.) I used Redis sorted sets to avoid concurrency issues. The bot itself interacts with the users directly. It’s capable of detecting even seconds of time changes🙃.


This has been an absolutely thrilling journey. Since my bots went online, the time students has spent in our Discord server has exceeded 3 centuries 🤩.


Even though I took 7 classes for 24 credits in my final undergrad semester, I spent countless tireless nights resolving issues likes the instability of Discord API. After all, how could I fall asleep when hundreds of thousands of students are agonizing over my buggy bot? (You’re welcome 😘) I also appreciate the tremendous help from the mods!

I hope you enjoyed the secrets behind this crazily successful bot. If you want to hear more about my ventures, please connect with me in any way convenient — follow me on Medium, sign up for my newsletter here, or even schedule a chat with me for any questions👋 at ZackLight.com Cheers 🤗