Design a Hotel Booking Service - System Design Mock Interview (with eBay EM)

An experienced engineering manager at eBay demonstrates how to design a hotel booking service. He walks us through his thought process and shares his insights on designing a scalable and efficient system.

Chapters (Powered by ChapterMe) -
00:00 - Intro
04:23 - How much storage would a hotel have for its room inventory?
17:08 - Booking a Hotel
23:36 - Booking System Speed Up
26:32 - Other than the scalability,
28:34 - Interview analysis
29:06 - System Design Tips

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[kevinli]

This is a BAD example of how you should do a SD interview. No matter how deep you understand how the system work, always start with high level disign and then dive deep. Especially when the interviwer ask you to do so. I am pretty sure the EM candidate in the video has a lot of expierence on this kind of topic, but I think the way he keep talking himself and ignored what the interview told him to do is definitely a red flag for any company's interview.

[mrinalaich]

Interviewer : Let's quickly go through the High Level Design of the major flows.
Interviewee: Yes, builds a block and starts writing SQL queries

[jonamep]

Its good to remind that the interviewee should be always asking and confirming with the interviewer about the decisions and next steps. You will probably get a better result if you use the interviewer as a partner in the system design.

[millen_basquiat]

Great episode! I loved seeing how an EM took his time to really dive deep into subjects. It felt like if the interviewer didn't rush him he would've given us a 5h masterclass haha

[katekho]

Hm, I don't feel the candidate was confident enough in his proposals. Swinging from one side to another without actually answering interviewer's questions

[CheeseDiablo]

He mentioned that there is an 18TB database but he didn't talk that there would be huge performance issues with that. Also, the inventory table approach is sorta strange - will he populate all the inventories for 10 years forward?

[UpBanarasWala]

It is Informative. I wish there were discussions around how the hotel search will work on geo locations and how the data will be partitioned (sharded).

[Anteater]

By assigning room numbers at check in instead of at booking, how do you guarantee that customers will be able to have a particular room for their entire stay?

[mansi_b]

What tool is being used here? This is awesome!!😊

[ricktastic]

I got a question: How do you maintain referential integrity across the 2 databases? I'm assuming one database would contain the Hotel table and the other the Inventory and Reservation table, the latter referencing hotel_id in the former.

[vladd]

Important topic to cover here: payment failures.

[prashantsalgaocar]

For the deadlock, a better way would be to provide API to the reservations API which would only be released once the hold on the room is released or that reservation is cancelled. This would prevent double booking using the reservations API as an argument would be the roomType and status of the room. I think the way it is explained in the video with constraints and other Sql statements needs a revisit.

[mahahrishi]

Which platform you are using for system design while mock interview ?

[jojay]

Also, didn't talk about sharding

[roliagrawal]

What about searching of hotels? Should not be using elastic search which is search database that can be optimisation

[amitsharma]

Nice session. Which tool are you using to draw?

[mansi_b]

@exponent plz let us know the tool he used!!

[RajYadav-fylm]

Enjoyed the session,
also timestamp helps

[chintanthakker]

I won't go for BFF, To solve under fetching and over fetching issue, graphql is much better option instead of building out BFF for each UI. Too much overhead cost and even complicates the system.

[jojay]

Should have gone deeper into Kafka and how orders are managed. Also, one of the biggest thing with hotels is location so he should have gone into that as well.