Ajay Ramachandran
Email: dev@ajay.app
Matrix: @ajay:ajay.app
Discord: Ajay#1922
For questions about SponsorBlock, please ask here
About Me

I enjoy working on programming projects. I am currently enrolled in Software Engineering at the University of Ottawa. The main languages I am working with right now are Java, TypeScript, and C++, but I also have worked with C# and Python in the past.

I am looking for a internship in Summer 2022 (May - August). Resume.

I am currently working on a browser extension called SponsorBlock. SponsorBlock is a crowdsourced extension to skip sponsors, intros, follow reminders and other annoying segments in YouTube videos. Users submit when the segment happens to the extension, and the extension automatically skips segments it knows about. More information and links to the source code can be found here.

There are currently users who have submitted sponsors and saved a total of years of people's lives. Check out the leaderboard.

I am a member of uORocketry, an engineering team at the University of Ottawa. I created a Java ground station and work on the C++ flight computer software.

I am a former member of Lake Effect Robotics, a FIRST robotics team who won at the Detroit world championship in 2018. I created Android apps for keeping track, analysing, and distributing other teams' performances. The app uses bluetooth to communitcate with a server device.


I also built an online database viewing system that got live updates from our data and allowed us to access it over the internet. It is available online here. The source code is available at https://github.com/ajayyy/LakeEffectScoutingSummary

Last summer I started work on a game called Voster Coaster, which is a roller coaster building game for VR headsets. So far, the game solely supports a VR track creation system using a spline based system. You can read more about this spline system here, here, and here. You can read more about my development of Voster Coaster here. This game is open source and available on GitHub at https://github.com/ajayyy/VosterCoasterVR

I also participate in the tri-annual Ludum Dare game making competiton. I have participated in 14 events since August 2014. You see these here as well as the older projects on their legacy site.

I have many projects not listed here on my GitHub Profile as well.

Below are posts from my developement blog. In these posts, I describe work I have done on some of my projects. You can view my entire development blog here.

Latest From My Development Blog

Categories - SponsorBlock
Posted 2020-06-14

SponsorBlock is an open-source crowdsourced browser extension to skip sponsor segments in YouTube videos. Users submit when a sponsor happens from the extension, and the extension automatically skips sponsors it knows about. SponsorBlock also has a public database and API for others to integrate and use.


The newest update added the categories. Categories allow you to submit a segment to skip that is not a sponsor. This allows skipping other things like intros, outros, and non-sponsor promotion. Most importantly, this ensures that people are less likely to accidentally submit non-sponsored content as a sponsor, just because they want to skip it anyway.


This feature has been requested since the beginning, but I was pretty hesitant to add it. In the end, I decided to add only categories that I felt were objective enough to prevent disputes on if something is correct or not correct. I decided to go with a category system instead of a tag system for similar reasons.

Switch to react

Previously, all injected elements were created with the document.createElement() APIs. This ended up being very hard to maintain once it got large, so I decided to redo all of them in react.


I decided to take this previously created skip notice and use it as the base for all the new UI. To make submitting categories simple, I decided to move them into an edit panel that appears after clicking submit.


Now, the UI is a lot more consistent. I plan to move more and more into in-video UI like this.

Stats so far

It's been a week now since stable rollout of categories. Here are the number of submissions for each category in the past week.



I have decided to revert treating skipping without clicking the report button as an upvote. It was a neat idea to try, but it made the data close to useless. Many people don't bother interacting and clicking the report button if there is an issue, so I feel it is better to have an explicit vote option.

I have also added a new "category vote" option. For now, only one person needs to make this vote for the change to occur, but this may change in the future. This will help fix the self-promotion segments that have been mistakenly submitted as sponsor before categories.


Precise Skipping

This was added back in February, but I haven't said anything about it yet.

Previously, skipping was using a very naive approach. It listened to the video.ondurationchange event and checking if it was currently in a segment. While this works, it is limited by the speed of that event call, which is ~250 ms on most browsers.

Now, the extension uses setTimeout to schedule skips in the future. When the skip is scheduled to happen, it checks again if it is the correct time, and triggers another setTimeout if needed. It also listens on all of the video change events such as playing, pausing, changing speed, etc. to reset the schedule.

This ended up working very well and made skips happen with a precision of ~5 ms - 15 ms. It should also use less processing power.

Cool Other Projects

Along with ports people have made with the API and database, there is another cool project that is being worked on.

A neural network has been trained on the SponsorBlock database and it works suprisingly well. The timings are not precise enough to replace humans yet, but the plan is to maybe use it for moderation in the future. It uses the captions to determine the timings. The best part, is that it is made completely by someone else and not me. It has made me very happy about my decision to make the database public. It is not being used yet.

Some icons made by Icongeek26 from www.flaticon.com