System Design Interview - Notification Service

Topics mentioned in the video:
- Functional (create topic, publish message, subscribe to a topic) and non-functional (high scalability, high availability, high performance, durability) requirements.
- High-level architecture of a notification service.
- FrontEnd service host components (reverse proxy, local cache, logs and metrics agents).
- Metadata service, distributed cache, consistent hashing ring, gossip protocol.
- Storage for messages: SQL/NoSQL database, in-memory store, distributed message queue, stream-processing platform.
- Message sender service, thread pool, semaphore.
- Duplicate messages, retry policy, message order, security, monitoring.

Inspired by the following interview questions:

[riteshthakur]

finally, someone talking about system design who actually know how things work internally :-).
Kudos to you brother!

[SamWhitlock]

The pedagogical steps in all of these videos are perfect. So many other "courses" say "here's how to design whatsapp" don't really start from first principles like this! (leaving me scratching my head wondering why they did something!)

I hope you find time to continue making these kinds of videos. I'd absolutely support via patreon or an online course if you made it. There's really nothing as well-presented as this out there!

[hadimajeed]

The best part of this channel is that Mikhail does not use ready-made solution available in the market. He shows us how to think simple and pushes for us to think what is under the hood. The thinking simple forces us to challenge our basics. Exactly what we need to prepare for System Design interview. Sadly, he has not been publishing any new videos for a long time now :-)

[ted]

This is somehow the best system design tutorial I've ever seen. Keep doing bro!

[sigorbor]

Absolutely the best System Design videos on the internet. I especially love that the videos are kept relatively short despite the huge amount of knowledge and explanation. Waiting for the new videos! Спасибо огромное, Михаил!

[vinibaggio]

I had an interview at A Very Big Company that asked me a similar question and this video was extremely helpful.

[saurabhchoudhary]

Best System design Video ever. No buzzwords and it also goes into depth of various components reasonably well. I'm waiting for more videos from you

[jituborse]

These videos are really high quality and in depth. Haven't found any others diving deep into each individual component specially with options for each component and pros and cons for choices made.

[bankybaba]

Highly underrated content that is not just full of buzzwords.
Please keep it up. Can't wait for more uploads.

[SatyanarayanaBolenedi]

I feel, This channel is hidden Gem!!!
Thank you so much for explaining things in great details!!

[amitdubey]

After watching several courses and reading several blogs yours is truly top class and one should watch any of your video more than once to consume it thoroughly.

[partrivedi]

I have been watching Mikhail's videos for 2 years now, and they continue to be extremely valuable, and the best sys arch videos on youtube. If you can grok all of his concepts, you will be prepared. Still, it would be nice to see Mikhail cover some of the more advanced topics that the book "Designing Data Intensive Applications" discusses.

[sunnyshang]

This is the most densely packed sys design video I’ve seen and it’s so full of good information. Really appreciate your work!

[DheerajKumarBarnwal]

This is mind blowing. I didn't expected this kind of system design tutorial on Youtube. Your style to explain HLD and then deep dive into each component, Its awesome and hidden gem. Hats off to you. I know it takes lots of time to create such content but please try to upload more videos.

[umber]

Excellent explanation!!!! You are teaching us how to think which is a very important part. Most of the youtube channels are just showing big and scary architectures of the companies which are not useful from the interview point of view or from the learning point of view.

[sergeyprytkov]

I'm glad that FPS Russia has found a new passion in systems design.

[hemantsethi]

I was speechless after watching this video. There were so many details and though process being discussed in it, that I ended up taking more than an hour(while taking notes and capturing thought process). A great video covering breadth and depth. I know it would be extremely hard to make up this high-quality content, but I would love to see more of those.

[funnyhjk]

Dude your videos are so good! Best systems design videos I've seen, love how you've especially tailored it for interviews. Thank you!

[mangeshshikrodkar]

Your videos are highly informative. Please create more such videos. They are way better than other youtube videos on system design i have seen. The only thing that I found missing is scalability numbers and estimates like bandwidth calculations, number of servers needed, amount of storage needed and how they can go as system stress goes as per growing userbase. In some videos i noticed top down approach like they start with numbers first and break down the question in some feasible small system. Here I see a bottom up approach where we start with small system and grow it with scale. I believe starting with small system and growing it is better than starting with big system and breaking it down and playing with numbers.

[junminstorage]

Thumbs up here!
I implemented a similar but more complicated system (with additional retry queue, message filtering or transformation, complicated UI with search capabilities) like you described in this video, it is a production platform service used by engineering teams in the company. Certainly you are a seasoned engineer and have hands-on some of the technologies you are talking about in this video.