Corrections: In the geohash length to grid size mapping table at 15:30 and 20:01, the correct values for 7, 8, 9 and 10 are: 7 152.9m × 152.4m 8 38.2m × 19m 9 4.8m × 4.8m 10 1.2m × 59.5cm

Hey KZfaq algorithm, if you’re reading this, I just want to say, this is the type of video you should be recommending to software people. K thanks

Best design video ever. I am so happy that Alex decided to make videos.

this video is a FLOW. Could not stop watching... Beautiful animation and narration. Perfect

Notes: - The SQL query at 20:27 would not work for the same reasons you mentioned previously in the video (prime meridian + equator). - You assume that the long/lat is the centre of the business/place, if users are able to add their own businesses this will probably not be the case - Businesses/places can span multiple grids (think of shopping malls) - Businesses/places can be bigger than a grid (think of airports) - At the very end you say it would "use the long/lat to rank the businesses and return to the client" (sorting), you also need to check if the business is still within the radius the user specified (filter); just because the business is in the same grid/neighbouring grids doesn't mean its within the radius they asked for. The first thought might be to make the geohash a list (of all the grids that it covers), but how do you calculate that? You would need a polygon (a long/lats for each vertex) that covers the (rough?) area of the business/place, then you get onto the trouble of validating that :)

So much effort spent in how to make this video so informative, well structured, precisely explained and amazingly illustrated. Thank you for sharing this with us!

We need more full system design videos like this one from you!

15:37 for 7-10, units would be in metre not km

In early 2000s we designed such a system for a popular real estate site very similar. We thought we had nailed the algorithm, but started getting complaints from agents and consumers. It turns out in that domain “distance” is almost always driving distance which is an entirely different problem and was much more complex in the days before quick road route planning 😀

Holy crap... finally a guy that actually knows what he's talking about. I've been doing this for 20 + years and this is how it's done. Kids you don't need to make it overly complex, just build it so it can scale not at scale.

This is hands down the best design video I’ve ever seen

Hi Sam, you mention use (geohash, business id) as a compound key so we can remove business from the table efficiently. I don't think that's the right thing to do. Instead of a compound key, we should just add another index for the business id. Removing a business thus would only need to check that index. With a compound key we'd need to calculate the geohash for that business, walk the geohash index first, then look for the business id.

I got this question on my Meta on-site interview. Absolutely bombed it.

Hey, Alex. I learn x100 times more from this video than from my past year in IT. Totally awesome content!

My best subscription on KZfaq

he explains like a teacher you would find in a school that everyone loves

Functional vs non-functional Functional: start with the user personas and what they can do with the app. This determines the API design. Non-functional: think in terms of latency, throughput, storage. This determines the architecture, the data storage and retrieval implementations.

This has to be the highest quality system design explainer video on KZfaq. * take a bow *

Currently the search API will need to query a few hundred businesses after the geoindex read. So business table will have 10x+ query load as the geoindex table

Fantastic system design content. Really appreciate the clear explanation of logic used to estimate the system requirements and then determine the approach to the design.

I just started reading volume 2 of System Design Interview and I'm really enjoying the content so far. Even more so when I realized you created videos to further solidify the readings! Keep them coming!

Today I learned something new! Thanks Alex!

This is by far the BEST VIDEO on questions like "Design Yelp". Pure Gold !! Thanks, Alex, and ByteByteGo team for your outstanding work.

The design elements are at another level! Great work! Keep it up!

This video should be taught at universities and bootcamps. Not only for the interesting topic but also to learn how to think about this kind of problem and system design in general. Thank you!

I have been following a number of channels related to system design in last few months. While many of them are brilliant, Sahn has a very unique and effective way of communicating complex technical topics. Thanks Sahn and team for this content. Hope to see more of these.

Wow, I'm an enterprise software engineer and from my work experience and knowledge, this is one of the best channel that digs into the ways of working and architecturing an enterprise software. Kudos 👏

I bought Vol 2 but I find video format slightly easier to digest. I really appreciate you making these videos.

This is an awesome video. I liked how you were able to break down complex concepts so that even beginners could understood them at a high level. Was able to learn a lot under half an hour about the complete picture of system design

This is such an underrated channel - very good visuals, concise speech pattern, and extremely well thought out approach to each topic

This is a god tier video. Please keep them coming.

2 minutes in the video and liked it already 👍. What an amazing way of explaining stuff, simple yet effective slides. Thanks man appreciate your efforts.

By far the best system design channel ever. Crisp presentation and fluid animations to easily showcase complex topics in a simple manner.

Thank you so much for starting to make these videos. Your step by step approach is so clear and crisp. Best System Design material ever!!!

like very much this kind of videos with an example of a system design! thanks

I think we should save geo hashes for each precision level (4,5,6) in the geospatial_index table..which will require more space than what is mentioned in the vedio.. isn't it so?

If you haven't work with geospatial indexing, how are you suppose to pass the interview? You'll probably be use up 20 minutes just trying to figure it out some on the fly solution with the one conducting the interview.

This was super fun to watch and got me interested again in algorithms and systems in general. I decided to go ahead and buy the two books straight ahead. So having a youtube channel definitely helps getting the word out :))

i hope u make 10 videos everyday so i can learn forever about system design. Thanks so much

You sir are a natural for teaching, please dont stop, you're doing world a favor! Cheers !

Absolutely love how succinct and on point the explanation is.

Please continue to make such wonderful videos. It’s pure gold, glad I discovered the channel.Thank you

I would index the city column. This would prevent table scans. You can then further filter using geo data.

wow - what a wonderful video. So well thought out - clearly lays down the ideas using very easy to understand visuals.Thank you so much Alex.

Another eye-opening video. Thank you very much for these high quality, insightful videos. Great work!!👏

As usual amazing video with great details. Thank you Alex. Wish to see more videos of length 20+ mins.

I've watched like most of the SD videos from YT, i could tell you guys this one is the best. Thanks Alex

Nice video!! A lot of good information in just 24 mins, very nice... Thank you.

Your approach is fascinating. It kept me watching the whole video and I find this very rare. Thank you.

Hi Alex, I think you need to correct the definition, at 14:00 onwards you are talking about quadtree, not Geohash, Geohash divides the grid initially into 32 smaller grids since the base here is 32. You may like to correct it.

Thank you for making this video. This is gold.

As humble as he is, his videos are super awesome too. Go alex..!!

If we can have some sort of video course also like the book you published, I would buy the course right away. The content and the explanation you deliver is really simple to understand and that's the beauty of a good Teacher. "Explain me like I am 5th grade" This really goes for you!

Literally was designing a location based service and wanted advice, its criminal that you don't have more subs and views.

This is one of the best technology videos I've ever watched! You explained everything very well and with great, informative graphics. Only small suggestion - maybe use a mono spaced font for the queries etc. to improve readability. Thanks for this!

I have your System Design Interview Volume I book... Never knew you were the author :) I learned CAP theorem, eventual consistency, and many others from it... I wasn't aware that there is volume 2.. will be adding it to my cart... Great explanation once again!

Would definitely love to get more full systems design interview videos like this from you. Great video!

this video is out of this world

Really good content, as always. You can also add a Kafka or some other streaming service to the business service, so that writes send events to the streaming system. You can then connect that streaming system to the write database as a sink, which will allow you to distribute the write loads evenly throughout the day and handle peak loads without consuming extra resources. Streaming systems like Kafka are so heavily optimized for such use-cases that even a relatively smol cluster with 3 4Gb+2CPU+100Gb should easily be able to handle these loads and have a lot of headroom if you use z-compression on the topic. As an added benefit you can perform change management on the database transparently to the user because streaming system will buffer all write operations automatically while the sink is offline. Streaming systems generally pair with a heavy read/low write system quite well.

Please continue making videos. The speaker did an amazing job, clear with a nice tone. The visual presentation is also nicely executed. 10/10, subscribed.

Great video! Question please: Usually these services will have filters like business type, pricing etc. Which table would you add it to?

A clear and in depth explanation of the proximity service design. Specifically I liked the detail ways to index the geospatial databse.

Great explanation with concise and well mapped out diagrams. Amazing!

Dude, your content is gold! I've been coding almost 20 years and prepared for interviews countless times. This has been one of the best content so far!

I had exactly this problem on my system design interview @ faang, failed it miserably)) Excellent quality of material here, will help a lot in future!

Beautiful poetry just opens up my eye. Overwhelmingly grateful. 🙏 and ❤from Chennai 🇮🇳

I am currently going through the System Design Course offered by Design Gurus on Educative which covers similar concepts but in a text based format. I have heard a lot about ByteByteGo's courses and books as well and I'm glad that I looked up this video. Thanks Alex and the team!

I really like this video, the presenter is very friendly and calm, please extends this, I would like to learn more. You got +1 sub from Tanzania 🇹🇿 Greetings from Tanzania 🇹🇿

You are the best person to explain that content. Thanks to share it with us!

This content is unbelievable. Will be checking out your books and newsletters!

This is gold! Toss in a Geosptial DB on your interview and it’s sure to impress them

I always really like your video. Very informative and clear.

This is the best system design video I've seen so far. Great job mister

Amazing! I always thought proximity system are much more complicated than that 😅

Gr8 design video. Thanks Alex for such high quality, clear concise explanation.

I have tried different videos but this one definitely stands out for understanding location based system design.

I am truly thankful for these videos, please keep making more !

Amazing! Beautiful! Super high quality content! So eager for the upcoming videos!

This one video introduced me to so many concepts. Thank you Alex.

Loved it, well made and highly educational. Looking forward for more of those.

Very clearly demonstrated and described. Love it! Thanks.

I learned so much in this video. Thank you.

This channel gonna blowup. The graphic designs are the game changer

That geohash part was superb... Damn, so many things I didn't know.

Amazing, the style of the video makes it very easy to grasp the concept!

wow the animation is amazing and intuitive!

Excellent content. I liked your structured way of thinking

The best System Design video so far! Thanks and Keep it going!

very good learning session !! thank you very much !

you opened my mind about the system design. unbelievable

This is awesome material. Thank you so much!!!

Amazing video. Only thing I'd add is timestamps on the video. But the content itself is priceless

Another great video with clear explanation and informative graphs for software engineers

excellent video ... I have one basic question, at 19:45, why do you use a compound key combining geohash and business id? if the business id is a unique key, then you are just concatenating some extra junk onto something which is already unique. or did I miss something, why does it make removal more efficient? good stuff!

Absolutely love this video! 15 year old me craved this information but got it after 8 years

I worked on a weather alert system that used S2, you more or less described its design and all the rationale for our decisions (we indexed by S2 cell id). Excellent video.

business info does not change very often so it would be a really good case for caching.

One of the best technical video i have ever watched

Mindblowing content and way of presenting it! Thank you so much! Keep it up!

Super Awesome !! Great work Alex !! Thank you so much for sharing the great design video.