Alexey Bykov
Staff Software Engineer at Reddit & Android GDE
I’m Alexey, Staff Android Software Engineer & Android GDE based in London.
Currently I work at Reddit where where I'm improving video experience on the main android app.
For most of my career, I have been working with large products with millions of active users. I got into
software development thanks to people who are actively sharing knowledge through blog posts and free
courses. This is why I spend a lot of my spare time sharing content with the community, and I sincerely enjoy it.
Over these years, I have given dozens of talks and written over 20 articles about Android.
Passionate about Kotlin, functional programming, Jetpack Compose, UI testing and Gradle.
What ExoPlayer Doesn't Tell You: Lessons from Reddit's Full Video Rewrite
At Reddit, we rewrote our entire video player from scratch — 15+ screens, millions of users, and over a billion playbacks a day across ~16K devices.
What we discovered along the way is that the hardest problems aren't in the docs.
We'll talk about:
- How we built a feed-first playback engine on top of ExoPlayer for scroll-and-play usage patterns
- How we designed a declarative video API where doing the right thing is the only path
- How we achieved 65% faster load times (P50), 20% faster (P90), and 67% less rebuffering (compared to our previous player)
- How a custom seekbar animation with Choreographer reduced slow frames by 7.3% and frozen frames by 7.7%
- How a playback failure affecting 2 million sessions exposed a blind spot in our architecture — and how we resolved it
If you have any piece of video in your app, this talk will save you a lot of time.