Great video, wanted to correct a wide-spread incorrect assumption about Relations in context of RDBMS. A "Relation" in RDBMS do not represent the relationship between 2 tables. Many believes thats the case. But Relation in RDBMS means a "Table". So all rows belonging to a Table is "related" set. In other words Table=Relation and it stems from the Set Theory.

you are my new favourite on youtube. Keep up the good work. Thanks for such informative videos.

Real good video i saw every video of yours and it really helped me cracking interview of one of the big 4.. i used concepts of this video in my design n architecture, and it really helped me.. keep doing good stuff man..

This is a good example of how an SDE i/ii would design the BMS in an interview, as interviews would like the candidate to talk more about how the 15 mins locking period (book to pay) is implemented and how the tickets are not oversold when the QPS is super high. Narendra I'm wondering how would you do if you are asked to record this video again after 5 years, thanks!

This is one of the high quality system design content. Very useful. Thanks a lot. As others mentioned, I'm also expecting LLD from you. As these days a lot class designs are expected during interviews, like designing a HTML parser, parking lot, ORM framework, DI container, unit testing framework.

You are really good in teaching.Please keep up the good work.It is helping millions of people like us to learn.

Absolutely Superb explaination in just 27 mins...i cleared most of doubts and gave knowledge on the latest techologies like NoSQL. Thank you, Narendra. Great job. May God bless u

Compared to other videos this lacks technical depth. How exactly locking happens , how theater API's works , why do we need logstash etc are required in my opinion

I can see you worked hard for this video Very clear and easy to understand Thanks for sharing

Great video , best explaination i have ever seen for BMS on youtube. Thanks a lot

I watched your other system design videos which are great. But I feel this one could be better if you would have focused more on the microservices which we will have in this use case and how they are interacting to fulfill our requirements. And less focus on specific technologies. The system design diagram looked more generic which should highlight more on solving the business problem.

Hi Narendra , you have explained the session very well. I am your consistent viewer/user and follow your all system design related series and concept.

Nice video. Initially I thought he can't do it but I was wrong. It went very well. Nice. Looking forward for more such videos

Awesome!! Explained really well....Looking forward for many such videos

Thanks for the detail explanation,it is very useful.

Excellent explanation - thanks a ton for this! :) I had a quick question - can we place Varnish in front of the Load Balancer?

Great video. I want to understand more about scaling a SQL and No SQL database and how to overcome problems like Replication delay, Consistency, Transactions and Different locking strategies on a highly available distributed database. Please can you make a video explaining this only. Thanks

Hey Naren .. 1) in the beginning of the video you mentioned theatre DB. Does that mean the db owned by theatre (and not BMS) ? So any db that needs to on-board to bms should expose lock api right ? 2) there is a db schema that you mentioned at the end. So these tables owned by bms will be maintaining a replica of some details like available seats etc which already is stored in theatre db is it ? Can you please help in differentiating between theatre db and db owned by bms ?

Short and simple - Thank You Narendra :)

Thanks. This is really great. One question. When you walked through user flow towards the end, you didn’t tell how the backend RDBMS comes in play. Kindly elaborate

awesome detailed explanation cleared lot of technology doubts as well.

In the architecture, the ELK stack is generally to be used for server log aggregation and searching. For Searching, You might just need any indexing database like Lucene based Solr, Elastic. The data can be indexed to the search databases from the transactional systems using a pipeline.

Great video. lots of information very well explained. Good work. Thanks. You could add a little bit more details on SQL and NoSQL data modelling along with entities you covered it would be great.

awesome ..covered almost all design aspects..

Great explanation of each comments, usage and use cases etc... Keep it excellence work...

Thanks a lot for the information. This was very useful. I just have a quick question on the theater server side. Who maintains information on the theater server side? In case of BMS, do we have a generic API in the theater side? Or do we have to implement it in the theater side as well if we have to support a particular theater?

nice video, understood the basics of system design. Planning to read about each individual unit you briefed in the video.

Thanks for the video. I was looking for system design for 1. Google Maps 2. E-commerce website like flipkart. It will be great if you please make videos for those. Keep up the good work. Thanks.

Like your indepth knowledge and explanaitions!

Do they use API's to access the theatre's inventory or DB Connectivity?

great job in detailed explanation

Very Good Information. Thank you so much for the nice content. One question from my side. U have mentioned that we can user elastic search for searching of movies, theaters, etc. So from where the elastic search will consume the data..? I mean what will be the input data source?

This was really helpful.

Doing great job !! Thank you :)

Love the dog barking on the background. These are great series. Thank you so much for simplifying the interview process.

You are doing a good job explaining high level overviews of architectures. This can be improved by reducing each video to byte-sized videos based on a concept or by provding duration markers.

Hi Narendra , I am big fan of your system design videos. I have question here. Since BMS follows micro service architecture, a comment or like by 2 users(geographically located at 2 different places) may be handled by two different servers. Then how does system ensure the consistency for number of comments/likes. Will system be eventual consistent ?

I have been lately following your system design videos which have good meat in it. Specifically for this video, I feel it could have been made better focusing on the crucial information - Strong Consistency handling with Optimistic Concurrency Locks, how it fits into this use-case - Good reasoning around the choice of DBs for Search and Booking and how does the data synchronization happen between the two - Pub-Sub model when we publish single booking event and how it will be interpreted by its subscribers for its own use-case such as notification, analytics etc.. - Reasoning covering the choice of the DBs such as CAP theorem fitment, scale, schema flexibility, data distribution - Clear separation of Functional and Non Functional requirements

If we want to store movie information in elastic search for faster search,can we store directly or does it has to go through logstash?I mean log stash is meant for this or only for logs purpose?

Your system design videos are very good. Please do more.

How to handle when other platforms books ticket. How to update the seat chart please explain that. This is very simple what you explained

Thanks for nicely explaining each and every details.

Thank you for such a detailed explanation I have two queries 1. As you said there is relationship between entity like movie,Cinema etc that is why we should choose RDBMS,But if read to too heavy should not we choose denormalized database design? As Music player has been designed in Cassandra's official blog. Where as per query table has been designed, of course for booking we can go with RDMS because it will need transaction. 2. I have seen different blogs where they have explained to first calculate TPS and DB sized required,It is really required in interview to calculate tps and db size

Is it a good practice to include RDBMS -> slave -> slave in real-time design? I believe there will be some inconsistency in the operations..

Great video ..this was very helpful. Can you do a system design video explaining docker and kubernetes in detail? Thx

Hey Narendra ... good learning for me by watching this video. You explained in a very good way. Could you please help me by letting me know from where should I check the further design details i.e. low level design

Hey, very helpful video thankyou for this one. Though, it would be great if you can make system design video of make my trip.

@Narendra L : Awesom set of videos. Please make a video on designing train reservation system (irctc) , Asked in Amazon multiple times.

brilliant , had a question about caching , how does the application keeps its data updated(from the theatre apis) in it's cache , is it like a very frequent scheduled caching/dumping of data from their api/db to app's cache ? a websocket between app server and theatre server ? Thanks again for sharing such a nice video

Thanks. It is a great explanation. It is said that the movieInfo, trailer for a particular movie is stored in NO SQL. How do we retrieve the trailer of a particular movie ? Can anyone please explain?

Thanks for such valuable information and time brother. :)

This is a sure fire way to flunk a system design interview. System design interviewers generally look for the application specific design details rather than bunch of product/technology propositions. Buzzwords without substantiation raise an immediate red flag.

Thank you for the video - I love how you did the diagram of all system components. Can you do a follow-up material on how to support that ticket reservation (in more technical details)? I've done an interview with Google recently, one engineer asked this sys desing question, but drilled in depth on that ticket reservation. Details from my interview - user can book up to 10 tickets (sets) at the time, it's reserved for him fo 2 minutes, there must be no collistions (like user 1 sees seat A23 as available, then spend 1 minute to fill the info, but the same seat booked by other user 2 and user 1 got error response)

Great videos. Your videos helped me crack interviews at Amazon and Goldman Sachs. Thank you❤️

Thank you so much. This helped me !

Very well explained :)

Hi I have one question. The theater tiket booking is managed by bookmyshow or they have thier own database and sever.

Hi Narendra, A great video again from your end. You are doing a fab job and I am very much thankful to you for doing this. I had a couple more questions to clear my doubts. 1) For ticket booking, is it just one service as shown by you running multiple instances of it in different application servers that are responsible to do so or that is also segregated in multiple different Microservices e.g. I didn't find any mention of having a User service, Payment service, Login service, Authentication/Authorization, etc? Is that given? 2) I do see that you have mentioned the Payment Gateway connectivity with JusPay but isn't that a limitation if we go via that route and shouldn't that be wrapped inside a service that we own instead of just invoking the Payment gateway in MS architecture? 3) I do see that you have mentioned Async workers but not sure about the overall processing and how these Async workers will be invoked and communicated in a sequence/activity diagram while booking the tickets? If you can share more details?

Hi Narendra, You explained very well. Well, the basis on the explanation, Would you please cover the scenario that If, the theaters would have their own booking system and they are taking bookings from various sources such as Book my show, Paytm and so on then how it would work ? Also, the counter question is.. how to handle the same request at the same time from two or more sources?

While dessigning are we not to suppose to include admin portal of BMS or anything else? Or The designing of BMS admin portal(entering movie details) has to go in a separate way?

Very well articulated. Thanks

Nice video, Can you please add video for retail website like amazon, When they will have sales how they will manage lots of request and availability of item for particular pin-code and how they will decide one day delivery of item. It will be very helpful if you will add this. Thanks

Great content ... very well explained in simple terms and at perfect pace.....

Hi, Can you help me understand the importance of covering the concurrent booking of a same seat at db level for this question. I mean in an interview, should I be covering the optimistic locking, versions for the seat booking table etc? I believe that is the main essence of this questions. Isn't it?

Awesome explanation..just one quick question which I have is..how to handle increased number of users logging in accessing the booking flow from concurrency perspective..thanks again mr. Naren

Thank you so much for your work 😌 Very educative

Very useful video tqsm bro

Hi Naren, Thanks for the detailed explanation. Can you please create a video for ticket booking system from Theatere side.

Love your efforts

How does it work with multiple partners like PVR and others who will also have offline selling?

Impressed, It has huge information bro

Excellent explanation as usual! Subscribed to channel.

Hi.. Thanks for your efforts in making us understand.. Wanted to know the approximate price to create such a website

@Narendra L Very insightful! Lot of concepts here to explore further! Wouldn’t a “API gateway” do the job better than ( a superset solution ) Varnish cache here?

Please include class diagram, database design and also some basic coding for all the system design . That will help much to visualize all the things behind the scene.

very informative, thanks a lot :)

One of the best!

Hi Narendra, i am currently working on movie ticket booking system and I want to know that is there any APIS available for listing latest movies and get seat availability of movie and book seat of particular movie. i also want to know that is there any way to reach out all theater's database? Thanks

Narendra i really like your video but i find LLD missing (Classes , uml diagram) . HLD part is covered only. Can you please give some information on LLD details and design interviews focuses on that aspect also. :)

Superb Video and Explanation, thanks for continued help.

Naren. Thanls for the video. Can you create a system design for Payment Gateway and a credit card rocessing system

Hi Naren, Can you please write down the technologies you mentioned(at 4:11 min) for handling the requests from BMS server to Theater server? Only Python Async is audible. Other 2 about GO and Lite weight thread are not audible.

hey , can u plz start series with oops design for different applications like shopping cart or medical system

Hi , can you tell what is the cost coming for like this system making with apps ?

You rock man.

Superb ! Great video.

Please add information about movie timings as well, rest all is helpful. Thanks a lot.

Excellent

Great video!! I had been asked this question in Amazon's interview for SDE2 role. They expect a lot much from a low-level design perspective like class diagram. You mostly cover HLD please cover component level design as well. Thoughts??

Hi Narendra, Thank you for the insightful video on system design. However, I wanted to point out that BookMyShow primarily functions as an aggregator. Therefore, the actual seat availability and booking processes are likely managed by third parties or partners, such as Inox, who handle the ticket reservations. Could you consider creating a video explaining how such aggregators communicate with multiplexes or chains of multiplexes, how they display showtimes and seat availability in real-time, and how they facilitate real-time ticket bookings?

@Tech Dummies - Narendra L - what is the best /easiest way to achieve high concurrency, as you know developing concurrent handling system is not easy, will you make a video on this if possible?

This is nice. I see app servers never talks to rdbms or nosql db directly. There could be lot of scenarios where I have to hit db directly instead of always the cache route.

Great stuff. Thanks

Can you please do a system design video on how a global distribution system (GDS) for travel works. It would be very helpful. Thanks

Thanks a lot sharing your in depth knowledge regarding the BMS. I will highly appreciate if you could answer one of my query , how do we put a lock on the specific seat for a specific time interval

Great explaination ....hats of🤓🤓🤓🤓

Good informative video

Great video, great explanation

Small correction, finally you said you are processing the log data using ELK. Initially you told you do user search for movie using elastic search. As per the design it should be queried and cached right. If we have that information in elastic search, it should be feeded in the form of some data which should not be from log

Thanks for the problem explanation. 1. Why is it necessary to cache separately at two tiers, Varnish and backend Cache? 2. What tools would you recommend for handling multi DBs, for promoting a slave to master, etc.?