Airbnb System Design | Booking.com System Design | System Design Interview Question

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Күн бұрын

Solution for System Design Interview Question - "Design a Hotel Booking System like Airbnb"
This is being asked by a lot of companies lately like Google, Twitter, Uber, LinkedIn, Visa, etc.
Prerequisites:
How to select the right Database for a Large Scale System: • Database Design Tips |...
Architecture diagram: github.com/codekarle/system-d...
Author: / sandeep1904
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PS: This is not the real architecture of any such platform. This is my take on how I would answer that problem.
#codekarle #systemdesign #airbnbsystemdesign #system #design #interview #amazon #faang #airbnb

Пікірлер: 249

@rohitkhurana7424 4 жыл бұрын

Very nice work brother..it helped us in building our system :) gratitude

@codeKarle 4 жыл бұрын

Glad that it helped :) Which system/which company you used this in?

@rohitkhurana7424 4 жыл бұрын

@@codeKarle an homestay app we soon are going to launch :) we are a startup.

@codeKarle 4 жыл бұрын

That's great to know 🙂

@sumitbuddy 2 жыл бұрын

@@codeKarle brother do you contacts you share i am from non it but deeply wanna to made it.

@AmitJigajinni Жыл бұрын

@@rohitkhurana7424 did your start up come out?

@abhishekkumarmishra8398 2 жыл бұрын

One of the most complete and perfect system designs tutorial I have seen. The breadth and detail is perfect as an HLD.

@saurabhchoudhary9260 3 жыл бұрын

One of the best system design videos I have ever seen. Hats off to you and the mechanism you told for handling the case of reserving hotel bookings

@mostaza1464 Жыл бұрын

Your videos are by far the best system design resources I have found on this platform. Thank you for these valuable materials!

@rishabhgoel1877 Жыл бұрын

Whenever I see your videos, it feels like I'm sitting in ofc design review meeting with a senior engineer as you don't throw fancy words, really appreciate your content _/\_

@coolvipool 3 жыл бұрын

Very nicely explained from high level to low level. Lots of concepts covered in the whole session.

@govi__y 3 жыл бұрын

Very well explanation. I liked the way everything is explained starting from overall architecture to smaller services. Looking forward for more such videos.

@commondev2595 2 жыл бұрын

One of the great System design videos out on youtube. Keep up the good work..

@rastogideepika 2 жыл бұрын

Very good video and extremely simple explanation, connecting us to the internals of the real world hotel booking.

@VindyDays Жыл бұрын

I really like your unassuming way of explaining the essence of your topic. The only suggestion I make is that make it a little more relaxed and casual. I would like to see the tension fade away.

@mkbhd2 3 жыл бұрын

First time on your channel, it's pretty good and easily articulated. One small suggestion is to take a break for few seconds, you are not giving any stops.

@zheli508 3 жыл бұрын

Definitely the best system design video I have seen! very detailed explanation of each part

@codeKarle 3 жыл бұрын

Thanks!! Glad that you liked it!

@aniruddhkhera510 2 жыл бұрын

Great videos on system design Sandeep. Thanks! I have one concern about the Airbnb design. You have used Kafka for multiple things and few of them don't really require or would be actually a not-so-good design. 1. Hotel onboarding: This hotel onboarding wouldn't really require an async service as I don't see this system as write-intensive. A simple sync REST API should work. 2. Booking of a room: The booking of the room by a user & removing the room from the available list should be consistent. I think here also Kafka's use should be avoided. In both cases, immediate reflection to the other users should be handled by a write-through cache policy. Let me know your thoughts. Thank you!

@rjarora 11 күн бұрын

1. Why is Kafka not a good choice? There can be many workflows that we can trigger whenever a hotel is onboarded, like sending a notification to customers, advertisers etc. All of that can be decoupled into a separate service and the service can consume from Kafka

@vishwas8110 2 жыл бұрын

Very good video. Ref the last part in terms of dividing dcs by region, it may not work if a user in USA wants to book say a hotel in India. You may want to rethink this to be an active active infrastructure with multi leader replication and IP any casting for low latencies.

@deathstrokebrucewayne 3 жыл бұрын

A wonderful playlist to binge watch :D More power to you Sandeep :)

@codeKarle 3 жыл бұрын

Glad that you liked it :)

@cakec9 2 жыл бұрын

i love you man. Your videos help me a lot in my prep. Keep it up!!

@shailytyagi4232 2 жыл бұрын

Your videos are very helpful! Please consider uploading a low level design series as well.

@nusefuckinlyf 2 жыл бұрын

Excellent explanation! Thank you for this.

@protyaybanerjee5051 2 жыл бұрын

I don't understand a few points here - 1. How is the available quantity only a function of room_id. If we are accepting date range in POST /book, it should be accounted for in the schema. 2. Assuming, we have that in the schema, we should also need to have an efficient query that checks for availaibility based on these three criterias.

@jayprakashdatani9405 2 жыл бұрын

absolutely amazing explanation!! Gratitude

@AbdelhameedG 2 жыл бұрын

Thank you very much, that was enlightening, God bless you.

@anirbanroy1524 4 жыл бұрын

Your videos are really great for improving architectural concepts.

@codeKarle 4 жыл бұрын

Thanks! Glad that you liked them. Do share these with your colleagues :)

@Clavicade007 5 ай бұрын

Amazing walk through. Thank you making this video.

@hardikshah9182 Ай бұрын

Very nice video. very thorough and provided all the necessary information in very easy to understand way. great work.

@stkmgr00 2 жыл бұрын

excellent video. very informative and useful. Thanks and kudos to Sandeep.

@elainaheraty3355 3 жыл бұрын

very clean explanation, thank you!

@aakashchandwani293 3 жыл бұрын

This channel should have millions of subscribers.. you are highly under rated. Keep doing the good work

@codeKarle 3 жыл бұрын

Thanks!! Can't get there without your support. Do share the channel with your friends/colleagues and hopefully we'll get there :)

@ahmadsalahudin928 3 жыл бұрын

Thank you for a great explanation

@Chesstreamer 10 ай бұрын

Well explained , to the point explanation , thanks a lot !

@mrkhanv 3 жыл бұрын

Awesome video, thanks for your sharing. I learned a lot from this video and others of yours

@archit_singh15 29 күн бұрын

thanks for the video! we should also talk about how we use semaphores when we access shared resources in a microservice setup.

@jiaweiwu9857 5 ай бұрын

This is super great. Thanks.

@SuperSimpleDev 3 жыл бұрын

Excellent tutorial!

@sekhars2073 7 ай бұрын

Great explanation and elaboration on the design.

@prabhatyadav3373 2 жыл бұрын

Ultimate video..hats off to u

@joshigurl 3 жыл бұрын

Every video is very helpful.

@akashkrishnan4524 2 жыл бұрын

Simply I love it 🥰

@Tarunv26 2 жыл бұрын

The content is awesome, really helpful to me. Please make videos on geographic information systems like- Google Earth, Street View, Voice recognition systems like- Siri, Alexa

@cbest3678 3 жыл бұрын

Really great video : Have some doubts below - So how are we storing available table. Are we going to store for 365 for each hotel . That will be inefficient. - Which service will pull data from hadoop cluster? once the analysis done from hadoop cluster aren't we storing it in Analytic DB? - Should not we store images first to s3/gcs then later cdn?

@harshasarikonda5078 5 ай бұрын

Excellent points. I had the same question. I think we shouldn't write images directly to CDN. We will store them in an object storage and CDN will cache it based on usage of the files geographically.

@prabhakarreddyg 2 жыл бұрын

Thanks for the detailed content

@akki4u 3 жыл бұрын

Very well explanation

@SuperAn0nymus 2 жыл бұрын

Great video! I think you missed a point where the hotel db needs to be updated with decremented available rooms when someone books a room via booking service, to technically there should be a room--updates src talking to kafka which decrements the available rooms

@pradeepk2698 4 ай бұрын

Golden video❤ , Great

@kanaiyapatel5691 3 жыл бұрын

Superb Sandeep. I am looking for Coupon management system design. its commonly asked across companies. On internet, there is not a single design for this.

@aarushim9248 2 жыл бұрын

Got a brief insight! Ty🌟

@yogaranjansingh504 3 жыл бұрын

Great work!! Please upload more videos

@elachichai 3 жыл бұрын

Excellent video overall. Automatic scalability: How much is the application developer controlling it (scripts, architecture, etc) and how much is the vendor component/cloud service provider (thresholds, metrics, etc) itself doing it? I see a component re-usage pattern. User Service, Hotel/Cab Service, Booking Service, Search Service - Elastic Search, etc across your videos. Great to see the modularity being put into action. You talk about trade offs and justify design choices which is a good but also reinforcing about first principles of components. Much more than an interview question which reflects knowledge and experience. Only disappointing thing is it is rendered by poor voice recording. Sigh!

@kunal4350 4 жыл бұрын

Your video is amazing and informative .Thanks :) Eagerly waiting for your new videos .hope u will make it soon

@Hangar1318 2 жыл бұрын

Love it how your mic makes you sound like you're speaking from the moon. 😂 Thank you for the video.

@amitk476 3 жыл бұрын

Excellent design

@vaibhavkumar903 2 жыл бұрын

Maja agya bhai, appreciated

@osdelhdez6796 2 жыл бұрын

Amazing video, thanks a lot

@gurjarc1 2 жыл бұрын

@23.07, i guess we need to mention we need to use which isolation to achieve. I guess check and set or serailizable isolation will help in race condition. Serialiazable isolation can be used with or without locks. it is better to use serializable shapshot isolation (SSI) to get the job done without using locks.

@AbraKadabra-lr9nq 3 жыл бұрын

Great work there !

@joeyzhou9789 Жыл бұрын

perfect video walkthrough mate!

@mayanksood587 Жыл бұрын

Very well explained. Just one point of discussion here from my end: Can we create some inventory-service and keep availability there instead of booking-service, this will help in well defined boundaries and responsibilities. Booking service should just keep the booking information and when booking is done, it can update the availability in one single distributed transaction. Let me know if there are any challenges/problems in the above said approach.

@petroskon6006 2 жыл бұрын

Really nice work! Bravoooo!

@jatilyadav4000 Жыл бұрын

Amazing video

@harishkandikatla9791 3 жыл бұрын

Nice explanation!

@akarkessel 3 жыл бұрын

@CodeKarlw I like this design, BUT: - Using a RDBMS for performing the booking lock may not be appreciated by all interviewers: I proposed a very similar architecture in a sr backend engineer interview @ Uber and I've been rejected with the motivation "He used a RDBMS for performing the reservation lock". It would be interesting seeing an alternate implementation. (Redis lock?) - The service crash scenario is completely absent in the design, specifically a crash of the booking service after a payment has been successfully performed but before the booking status update - How do you maintain the datacenter database aligned? Shared kafka topic consumed by an align service? Thank you for your work anyway!

@amitmandliya6577 3 жыл бұрын

Wonderful!

@rajeshkishore7171 3 жыл бұрын

Excellent

@subhedarsanchay 2 жыл бұрын

Simple and Nice video. Loved it. However, it did not cover searching of hotels in a radius. It would have been helpful to see how that might have been done.

@deep8843 Ай бұрын

Really helpful!

@buvanaanguchamy9589 2 жыл бұрын

Hi Sandeep, Great video Content! Cant thank you enough! Could you please also explain the cancellation scenario

@mugdeeify 2 жыл бұрын

Thank you for the insightful video. Very well delivered. Question though, Where do you place users on the waiting list, who have reserved a fully booked hotel that suddenly becomes available?. Do you need a queuing system or they can be placed in the archival

@deepak17123 3 жыл бұрын

Great!! well explained.Can you post video on Flight Reservation System?

@mysterygirl191 3 жыл бұрын

Superb explanation .. thank you for this . One question do you have more explanation on Apache Kafka and Redis as separate topics ? It will be really helpful.

@edwardteach2 2 жыл бұрын

U a System Design God

@user-ps4jq9hx4k 10 ай бұрын

Thank you

@ano0810 3 жыл бұрын

Great video Sandeep. Quick tip for Product Managers looking at this - I think the first 15 minutes and then 32:20 onwards is pretty relevant. Wanted your thoughts on something: The safest way to interact between the booking service and the search service would be to have a single DB where locks are taken on the respective fields when a booking is made. This would guarantee that no room is double booked ever. That approach seems very very 90s and theoretical. But is there ever a case in your design that the delay between syncing the search and booking service through Kafka can cause a double booking scenario. Are there any other cons you could think about this architecture? Thanks in advance.

@balasravandindukurthi4702 Жыл бұрын

Hello, we are using only one DB for booking management. There will never be a case where there would be a double booking. there can be a case where in search experience hotel is shown as available but on trying to book - it might be shows as unavailable. But this should be in only very minimal cases

@ameyjain3462 2 жыл бұрын

Another way to compare database is based on hwat is your query pattern and how you can use the functionality of database.

@revatipandit1220 4 жыл бұрын

Can you please create a video focusing only on the "search hotels". I am sure that will be interesting

@jayantlvsv 2 жыл бұрын

I'm wondering how we can get quick Search results with filters like available_quality, date_range and room_classification.

@RahulRai2048 4 жыл бұрын

Nice Video. I just have a question on inventory. So here we are keeping the hotel rooms inventory in ELK for powering search and also in the MySQL DB (available_room table) for booking service to interact with?

@priyankapyati4648 2 жыл бұрын

Explained very well. Please make video on online pizza delivery app system design or online shopping system design.

@knight0856 3 жыл бұрын

Thanks Sandeep ! One request, can you create one design tutorial on Rate limiting !

@rainenguyen3349 Жыл бұрын

Thank you very much for sharing your knowledge. I have a question regarding search: hotel inventory is associated with time. For example, this particular hotel does not have room now but will have room(s) in the next 2 days. How do you store data in your ElasticSearch to allow searching for rooms given the checkin, checkout time?

@krishnashrivastava7771 2 жыл бұрын

thanks brother

@shishirkakhandki9230 2 жыл бұрын

Thank you so much, sir! Very detailed and extremely well explained. Grateful to be learning from a talented engineer like you, free of cost here on KZfaq! _/\_ Also, if you could create videos on LLD that would be really helpful.

@obamabinladen5055 3 жыл бұрын

This is really top notch work. Decent depth as well. Are you SDE3 or Principal?

@jayantlvsv 2 жыл бұрын

Ready nice video detailed explanation. I'm wondering how we can get quick Search results with filters like available_quality, date_range and room_classification. Please make a video on this.

@souviksen6071 3 жыл бұрын

This is an awesome explanation. Requesting you to please prepare one system design video for Flight Ticket booking system also.

@codeKarle 3 жыл бұрын

That would be very similar to this one, just that in that scenario, instead of hotel being the primary entity, it would be a flight ticket. Rest most of the things would remain very similar to Airbnb, be it the search flow, be it the booking flow, be it the analytics. One difference though would be the way we interact with the third parties(Airlines) and do reconciliation. We'll try and do a video on that, but that might take some time :)

@gnanstar 4 жыл бұрын

Contentful video,very nicely explained .. Basically i was looking out for scenario , where multiple people select the same hotel almost at the same time , or like how we do solve the race condition in such a huge system ..? by avoiding same booking with multiple people.

@MonisYousuf 3 жыл бұрын

The property ISOLATION of ACID properties deals with that. So, if you set the Isolation level of a transaction (T1) to be Serializable, no other transaction would be able to write into the tables involved in the first transaction (T1). So, whichever transaction starts first, that transaction will end first. In the case of a booking scenario, let's say, T1 and T2 are two transactions booking the same room for same dates at the same time, If T1 starts first, in the Serializable mode, then T2 will have to wait until T1 completes. When T1 completes, T2 sees that there already exists a record which it is trying to book, so it will have to rollback. In that case, you send a message to the user, that someone already booked it.

@shalini-j-2r 3 жыл бұрын

amazing explanation. Have one doubt here, why you are using redis between mysql clustes and booking management service? if we want to put recent booking details in redis then may be it would be having some TTL and user can come to see booking details later also and it would be hiting db always. could you please elaborate use case of this?

@shrinikethr3797 3 жыл бұрын

Amazing Video thanks for sharing this ,Can you please add Summary for all your design videos , I see you have added for a few which gives a lot of sense . Thanks Again for all the great work 👍👍👍

@codeKarle 3 жыл бұрын

Thanks!! Yeah, that is work in progress. Other summaries would be live soon in a couple of days at www.codekarle.com/

@apshiva Жыл бұрын

Thank you for this presentation. It is well explained. If possible, request to add ticket booking app design like bookmyshow, please.

@jlokj 3 жыл бұрын

Can you prepare the same for movie booking system? It looks similar to this, but in movie booking, user has the freedom to choose which seat to book. The DB schemas might be different.

@shinysingh1797 2 жыл бұрын

Great video. I have one question though. How are you generating/updating the available_rooms table? Where's that data coming from to begin with? Thanks!

@yongjiaoyu3770 2 жыл бұрын

That's probably from UI/App for hotel to hotel svc right?

@arjun.s5112 3 жыл бұрын

Great stuff. Thank you so much. This definitely gives me more than an idea of how to go about designing. QQ. do you have a write up for this like you have for Amazon-system-design.

@balasravandindukurthi4702 Жыл бұрын

Great video. One thing i that i found missing in this design is : When admin of hotel adds new rooms -> there is no flows that updates rooms availability in DB of booking service Please let me know if i i'm missing anything on this

@nakul2k Жыл бұрын

Thanks!

@srikantd6054 3 жыл бұрын

Nice Explanation , I am having one doubt here , From Hotel Service Storing the data into one MYSQL Cluster, and from Booking Service Storing the Data into Another MYSQL Cluster, then How do they in sync ? I am mean Hotel Service data and booking service data in DBS.

@joshitamishra3949 2 жыл бұрын

Best system design video i have watched till now, i was able to relate to most of the explanation given for choosing the right storage at right place. Precise and to the point.

@gamervihaan772 3 жыл бұрын

I have a concern here. We cannot search for hotels from ES cluster. We need real-time information about the hotel rooms inventory for searching. So hotel search should come from you booking my sql cluster. We can use cache with a small TTL for search patterns though. Thoughts?

@BondhanNovandy 2 жыл бұрын

Thanks for sharing. I have questions: - Is the user service is together located in Booking service? - I guess better to have noun in the API design, e.g. booking instead of book. WDYT?

@dorjeetsering937 3 жыл бұрын

Very nice work @codekarle. Only thing to improve is that your voice is not very audible. There is some noise.

@akshaybankar2756 2 жыл бұрын

How does checking for room availability work from your design? We could have multiple bookings for the same room for different dates.

@NeerajDhariwal 3 ай бұрын

Thanks for the lucid explanation. I have a couple of questions: 1. How do we maintain consistency in this design. If a room has been booked, it should immediately be blocked. Using Kafka would introduce certain delay, during which another person can book the same room. 2. Can't we use MongoDB for hotel database? A hotel has complex properties, like reviews, amenities etc. Don't you think a no sql database would better fit the use case here?

@mrharshrajpal Ай бұрын

we can always have hotel/room metadata in mongo db

@tigeruppercut7 3 жыл бұрын

Whats the drawback of having two separate databases for hotels and booking? Can you mention problems that might arise due to consistency issues and how to resolve them?

@zoomonnick6517 2 жыл бұрын

When does the Booking Mgmt Service use Redis vs When does it use Cassandra? Do we just use the data from cassandra when dealing with bookings going from reserved to a terminal state?