Understanding of RENO for Project manager and Product manager: k. Season 1: B 1

Venkatesh Varan
3 min readMar 24, 2022

Netflix is an online streaming video stream platform with 220 million active users and we users will change our name, add or delete items from the watch list and enable notification for the new releases. At RENO come into the play and manages all the notification so that we can receive them periodically in need.

RENO — Rapid Event Notification System, on a variety of actions throughout the session RENO takes care of it and gives the user proper notification for the devices. If you are using Netflix in Phone (Android or Apple), TV, Tab or Web browser, and Other latest set-top box which runs of internet support all the devices what you logged as will get a notification at the time when you are using Netflix. For eg., You changed your profile name on the mobile platform and it will also reflect in the same in the Smart TV as well. And main motivation is that our user should not miss a notification of any type in any devices across that where our RENO comes into play and keeps the system by sending consistent notification to the user.

So, here are use cases or problems RENO solves,

  1. View activity

If members “Continue watching” a video on one device it will sync to the other device as well, and updates the view list

2. Personalized Experience Refresh

Netflix recommendation engine, which helps the user to view the recommended video based on the user’s performance

3. Membership Plan Changes

If the user changes plan in the device it will also be reflected in all devices

4. Member “My List” Updates

If the user adds a video to “My List” or deletes it will be reflected across all the device

5. Member Profile Changes

If the user changes the Profile Image on the device it will reflect in another device as well

6. System Diagnostic Signal

Netflix will be sending the signal to the application in devices to help troubleshoot problems and enable tracing capabilities

Now, we start with a single event source how the Manhattan (you can learn more about it here) by adding an indirection event for RENO. And we prioritize the events which notification must to reach user instance is mapped with the priority and traffic patterns.

Now have set up and prioritized our event now the notification will on the basis of the Push-and-Pull delivery model since RENO can not survive on just the pull delivery model because we to mention it across the different devices in the platform.

Once the notification is viewed on one device it will not show in another it validates and helps limit the outgoing traffic footprint considerably so RENO is just configured for the targeted delivery

Due to this RENO has the problem that relies on several upstream systems as its traffic source and simultaneously produces heavy traffic for different internal and external downstream systems, so we are instrumenting the RENO with a real-time stream processing application called Mantis (you can learn more about it here) It allowed us to track events in real-time over the wire at device-specific granularity thus making debugging easier. Finally, we found it useful to have platform-specific alerting (for iOS, Android, etc.) in finding the root causes of issues faster.

And, RENO developed such a way that the design decisions we made early on paid off, such as making the addition of new use cases a “plug-and-play” solution and providing a hybrid delivery model across all platforms. Netflix base increasing day by day user needs proper update and usability with the latest update to continue to watch movies with any hustle.

Currently, there many video streaming platform have incorporated the RENO to enhance the product usability.

Thanks and Regards,




Venkatesh Varan

Product | Efficiency | Productivity | Game | Poem- I blog