UBER System design | OLA system design | uber architecture | amazon interview question

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Systems design: What is the system design of the Uber App?
Systems design: What is the architecture for the OLA?
Systems design: What is the software design of the LYFT App?
Arch diagram: imgur.com/a/c1...
Answer to all of the above questions is here, though I have explained much about Uber's system design, but for interviews you can adopt the same answer to all of the cab aggregation services question.
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30 сен 2024

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Комментарии : 568

@vaibhavbhardwaj2244 4 года назад

Key takeaways : 1. Web sockets must be used for such application as the communication is real time and lot of to-fro communication happens between client-server for which web sockets work the best 2. the location update happens asynchronously using a queuing system like KAFKA , as this is a write heavy operation . 3. Each location would map to a grid id on a 2D matrix and the location service would use the nearby cells on grid to fetch the drivers in vicinity. 4. The APP servers are stored in a Ring (based on consistent hashing) and each APP server caters to different set of cells of the Grid. Each node knows about each other through config publishing mechanism and any call to any server would be redirected to the correct node

@divya-dj3pl 2 года назад

This question was asked for me 15000 per month job as a fresher🙂

@Curious_Citizen0 Год назад

In a startup right?

@pankajchaudhary5925 9 месяцев назад

If you would have answered then you could have owned the startup at one point!

@abhirajkumar882 15 дней назад

Where do you work now?

@dextermorgan1287 3 года назад

Few suggestions : 1. Websocket is being shown as an API Gateway which is incorrect. 2. Websocket comes with its own complications like failure on firewalls. 3. In system design, we don't focus much on the implementation logic. Good that you explained concept of cell but that's not a very important piece. Thats more of a low level implementation. 4. Support for NodeJs is partially correct. Java or C# can scale better than NodeJs in a multi threaded environment. Though Nodejs is fast to develop and deploy. But when threading comes there are better alternatives. 5. Discussions should be more focussed around DB and type of DB choices with reasons.

@mdalaminmahamud3775 5 лет назад

I really appreciate the amount of effort you have put for this system design talk. Thanks for sharing such valuable information in a short time span.

@vm1662 2 года назад

Binge watching the system design videos on this channel. This is pure gold and free on youtube for everyone to watch! Thanks a lot Narendra. You clearly put in a lot of effort making these videos.

@PsychologyinTamil 5 лет назад

Amazing work Mr Naren.

@arulanandhan6685 4 года назад

Hi Jithendra Sir, How would you know this guy? I'm a big follower of you and Naren.

@eruabid9190 5 лет назад

Great content, laid out in a concise manner, appreciate the effort you put into making these systems design video series, keep it up. Cheers.

@puru.gupta901 2 года назад

Remind me of Chester Bennington

@antonyspiano2403 4 года назад

I saw you saying sorry, Boss you are a genius and selfless person. Never say sorry again. I get reminded of mistakes and never said a sorry. Great work!! and Thanks for making me love my job .

@bostonlights2749 4 года назад

3rd Sept 2020 427,340 Views | 72.8K Subscribers

@bhagyashreemahale1018 4 года назад

Hi, Thank you for such a great video. I have a few questions as listed below: 1. As you mentioned that 4seconds of the interval a server will get the update of drivers location. ETA calculation will be based on that last update. As you know the driver keeps moving. So the system has to do that calculation within 4 seconds only, please correct me if I'm not wrong. 2. All nearby driver will get the Ride request and it will work on First accept first serve protocol. If there is some conjunction then how a system can handle it. Suppose two drivers accept it at the same time. 3. How does this system handle the cancellation and refund process? 4. Is there any Surge module and how does it work? It would be appreciated if you could answer these. Again good job & Have a nice day..

@AbhishekGupta-hh9tc 4 года назад

1.yup you have to do the calculations in 4 secs although that's a safety buffer you hardly require more than 1 sec to search nearby taxis using hash tables. These are maintained real time in caches and rams(data structures) instead of hard disks(databases). Only the ride related coordinate data is stored in nosql databases for analytics, crime investigation etc. 2.system would probably choose the one which has good ratings and who accepts many rides each day. The philosophy behind this is to provide good customer experience (driver ratings) and to fulfill long term profit expectations (no.of rides/day). 3.untill the cab reaches the customer , system does not state that cab as 'locked in ride'.System keeps on receiving location updates from cab although it knows that the cab has been booked. It doesn't disappear from eta and nearest cabs search calculation scene. you only recieve the data of 'free' cabs near u but as soon as any cab near u gets it's booking cancelled , that taxi starts appearing in your map (this doesn't happen instantly there are time windows for this). 4.yeah there is a surge module based on machine learning which tells cab drivers to locate to region s where there is high probability of getting rides thus ensuring amazing customer satisfaction and revenue generation for company. I hope you find this explaination meaningful. Stay curious!!

@jay-rathod-01 3 года назад

@@AbhishekGupta-hh9tc Just curious, what is the size of cache and ram memory they use? or are those memory also allotted as per locations? like i believe the information is just a tuple with very less memory consumption so maybe state wise or city wise...

@AbhishekGupta-hh9tc 3 года назад

@@jay-rathod-01 bro it's a distributed system. It appears from outside as if it's a single system but there are many servers on multiple machines. There exists a virtual memory distribution across multiple machines. This distribution is not 100% optimal. For instance, suppose there are 3 servers, each one is meant to serve 1/3 utilisation. But, due to optimal real time memory distribution or allocation, it could happen that one of 3 servers has major chunk of the distribution and hence would be forced to serve more than 1/3 utilisation. So, we don't have real time distribution. We rather have periodic distribution. Also, we don't have continuous memory distribution (it can happen but is insanely prone to errors) across machines. It's best if we can limit a server's memory usage till the very machine on which it's hosted( ideal case doesn't happen often). As far as data structure is concerned, hash table is the easiest one that we can have across multiple machines. In case of Uber or any other similar app, they use distributed hash table along with binary search. I am glad that u asked me.😊

@danielmapar1 5 лет назад

Just a quick correction, DNS is part of the Application Layer in the OSI model. On that note, it is actually part of Layer 7

@jojocabs1913 3 года назад

Hello sir we can make app for you check our readymade on demand taxi app ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-UuP4uck7VNI.html and connect with us by details in description

@deepakzworld 4 года назад

Love your videos but a couple of main things missing in most of your videos that is highly desirable in job interviews is: DB schema and basic API. These two components might add another 4-5 minutes to every video but will make these videos almost an exhaustive study of the design.

@namrathas5804 Год назад

Thanks Narendra, this vlog was very helpful and thanks for your time and effort.

@dalitex-c4885 5 лет назад

Good but was expecting to see Capacity estimation, CAP , Sharding ...etc

@karolyholczhauser1528 4 года назад

exactly. This is NOT a system design interview approach. This is how the system works. Still useful, but different though.

@gouravkhanijoe1059 6 лет назад

Since driver location is getting updated every 3 seconds, will it not be a costly operation to update the grid cluster every 3 seconds?

@TechDummiesNarendraL 6 лет назад

it will be, may be you can have adaptive updates, Basically update frequency based on speed.1. Say if the vehicle is not moving at all, there is no need to update 2. If the vehicle is moving too fast the updates are frequent

@swapnilpatil6085 2 года назад

Awesome video ! Please help me with below two questions. 1. Driver location is updated to nodes in hashring depending on s2 cell. Since car is in motion location and s2 cell will keep on changing. Suppose location is store on server s-1 which handles cell c-1 and now driver has entered cell 2 and location is updated to c-2 which is store on server s-2. How would server s-1 know that driver has moved out of cell c-1 to remove driver from it ? 2. Is driver location stored on cache for each server or there is cache cluster which stores location information.

@TusharMudgal 5 лет назад

Hi Narendra, awesome explanation. Highly motivated in learning system design. Though, I have a question, Can you please make a video on how to efficiently make a search service that searches on billions of records.

@vivekchoudhary8745 4 года назад

this is gold, and the efforts and your persistence is beyond praiseworthy

@CestuiQueTrustBeneficiary-KING 4 года назад

Do you do contract work? $$$ 🤑 I'm looking for a team to help with ui design and supply management systems.

@twyla0071 5 лет назад

Keep posting valuable content on system design. Awesome This approach to system design interviews says that we have a preconception about how things should be. I have a suggestion, please show the approach from bottom up, i.e from scratch. The video starts with a full fledged version of a system already designed. How would anybody come up with such a detailed design at the beginning of the interview.

@NitishSarin 6 лет назад

Damn, you are just so awesome. You will definitely definitely earn more and more subscribers, just like how Gaurav Sen did. You guys are what every developer on youtube needs. Thanks for the initiative! :)

@TechDummiesNarendraL 6 лет назад

Thanks for the kind words :) this means a lot !!

@UntamedRogueMavrick 5 лет назад

Hi Narendra, Thanks a ton. I could understand the system design better and could get the job offer from the knowledge I got from this series. Thank you not only because of the help you did by posting all the videos on system design but also for helping me by answering my queries personally on the LinkedIn. I kept on browsing the youtube to find out some quality content, but here is the home of understanding almost all types of designs questions.

@TechDummiesNarendraL 5 лет назад

My pleasure, and thank you

@krishnan30990 5 лет назад

Hey man ! Very useful and nicely presented. I've started loving all your videos and have literally binge watched 'em all. In this video, I was also expecting you to cover up how Uber matches the pool rides .. basically a map route matching algorithm.. if you could brief on that, it would be very useful ! Thank you and wishing you huge success ahead !

@adhipvihan4777 5 лет назад

Honest feedback This is a pretty unpractical way to approach design interview. You have just basically explained how the uber architecture work. I would not like to work for a company which wants me to cram up this architectural information, very specific technologies, libraries & spit it out. System design is a open ended discussion, you discuss approaches, APIs, data modelling, scale of the system, caching etc.

@TechDummiesNarendraL 5 лет назад

Agree to your points, But no where in the video I have mentioned this is how you should answer. This is video is to learn how the system work, not to copy the answer or to show what the interviewer expects!! we are no more school kids to copy/remember and answer

@funpoleece 5 лет назад

@@TechDummiesNarendraL Your title includes "amazon interview question" which leads viewers to believe that this is how you would answer the question in an INTERVIEW!

@sivakrishna5557 День назад

Can please make a video explaining database used by popular techs for specific usecase

@dev-skills 5 лет назад

Please also share how does the ride fare calculation is done by the Uber service.

@bharadwajas4864 Месяц назад

How it Works Rider Request: When a rider requests a ride, the request is sent to Disco. Driver Availability: Disco identifies nearby drivers who are available and meet the rider's requirements. Matching: Using complex algorithms, Disco matches the rider with the most suitable driver. Notification: Both the rider and driver are notified about the match.

@kaustabpaul4514 6 месяцев назад

im still confused, that nearby cabs are detected by S2 library's proximity calculation or by ETA calculation. I think google matrix API gives far far better real time info of ETA than s2 library's proximity score

@sharad_dutta 4 месяца назад

A lot of things are incorrect, he said when users request for ride, 13:30, he said user request lands on Web Socket, users request is better with an https request since it is a request made by decision and not auto generated by event, using web socket to handle user ride request is wrong, web sockets are used to have a bidirectional communication between client and server, where client gets events (responses) whenever there is a change, just like how the Instagram notification system works. And then saying each region X is a server is too much, there must be a region service responsible for filling region blocks, region service will fetch location from driver client app (can use a producer which will generate Lat and Long of driver every, say 5 sec or so), then the Kafka cluster will have topics which will listen to produced location pings, and consumer in region service (which is responsible for allocating drivers to corresponding region) will consume and put the driver in respective region, probably store as a meta. I mean there is no right or wrong way to design HLD but using the right technology always have right and wrong about it. Good effort though.

@NileshAkhade 11 месяцев назад

This guy made a mess. There's a well defined strategy to approach system design problems. This guy mixed up all the things. One should start with identifying actors and use cases. Then should talk about scale(expected) and then jump to choosing products(kafka and all)

@dhyanimation 4 года назад

This is gold, I'm looking forward to how tech enables ground ops for mainstream products.

@sherazdotnet 8 месяцев назад

Do like your videos but a couple of comments: 1 - Instead of explaining how Uber (or other big system) do what they do, it'd help more if you first state the problem then solutions then how a company is doing and why its doing. In your approach, listener has to do the reverse engineering to figure out why Uber does the way it does. 2 - When you were explaining Gossip protocol, you pointed out its purpose is to reduce the work load. I believe that's not its purpose. As the name suggests, gossip is all about talking to others about someone else. In this case, the protocol goes to different servers and tells them what other servers do. This way, all nodes (servers) ends up knowing about each other. Once each Node knows about other nodes and what they do, we don't need to forward the request to a specific node or know which node does what. We just send the request to any node and if that node doesn't handle the request, it will send it to who ever does. Gossip takes the component (Zoo Keeper) out of picture who's main purpose is to know and keep track of who does what. 3 - You mentioned that if one of the cell goes down then the responsibility is given to one of the free cell. I think in consistent hashing, it doesn't work this way. Instead, the calls get forwarded to the neighboring cell (clockwise or counter-clockwise).

@tapasyayadav5148 5 лет назад

Thank you so much for such a super useful video, good explaination.keep up the good work.

@sunitasingh-kv2ur 3 года назад

Hi, we are coming up with a EV Fleet service in Mumbai, For Fleet Bookings we have appoint a Company to make a App for our cab service, Company is from Chennai they do customise Templet Apps. and we don't have proper knowledge...we like your video....can you help us or anyway you can guide or any association we can do with you. we are a startup company, your help take use to another level...Please feel free to give your feed back. Our motive to start this Fleet company to generate jobs in our country and specially help those who lost there earning family members during the Covid -19, we are coming up with 50% Women Drivers hired by us only.

@reddyr9027 2 года назад

Naren Ji, I have Web application and Apps Redy , Can i Deploy on AWS. Those all Backends covers on AWS..?

@neoli8110 4 года назад

to talk about Uber payment design would require 20mins... I hope the video could focus on the core part of Uber design. which is the Supply Demand maching. S2, Geohash, or quard tree.

@youwillyou7905 3 года назад

Guys, check out JaguarDB, which is awesome. Time series data, geolocation data all in one natively. Automatic time window rollup.

@bhaskarm632 4 года назад

LP t-shirt

@fccccp2023 5 лет назад

Is supply|demand an single machine or a group of machine? If it is a group of machine, how will the region server in Ringpop know which supply|demand server I should send the riding request to? (I assume different driver will keep a websocket connection to different supply|demand machine)?

@sahilguptalive 5 лет назад

I have a question, how does Google manages to show fastest path in Google Maps. What is ita system design and algorithms being used. Please help.

@TechDummiesNarendraL 5 лет назад

Google's Algorithms are complex. what they use is combinations of algorithms + realtime traffic information taken from all the android devices in the city(In a way every android phones contributes to realtime traffic view on map). The number of Android phones at any given point which is overlapping on road gives the density of traffic. Also based of how fast the android phones are moving, you can predict weather the traffic is slow moving or fast moving. Based on the traffic movements + traffic density, the weights between nodes changes(nodes are two end of a road segments). Google also caches the routes users are taking and breaks the routes in to combinations of paths (without using maps) and based on the cached paths, google's algos(ML models) learns on its own, it trys to understand traffic signals, one ways, blockages, road conditions and narrow passages etc... Now with all of the historical routes people are taking + Realtime traffic + Road conditions google suggests the best and fastest path. I dont think they are using Dijkstras algo. or A* algo(not sure)

@sahilguptalive 5 лет назад

@@TechDummiesNarendraL thanks a lot. This question was asked to me in an Amazon interview. I couldn't answer it.

@shrangisoni8758 5 лет назад

@@TechDummiesNarendraL so they are tracking our location even when gps is off right?..

@DeependraTube 5 лет назад

@@TechDummiesNarendraL How can we buy or lease such data from Google or fb or others, and start our own startup services on top of these data ???

@babumon5351 6 лет назад

Thanks a lot..This is so complicated..wow..

@pratiksarvan 4 года назад

This is not system design approach. This explains how Uber may be working. Could you please explain how we can build our own system like this? Not sure why are you explaining the technologies in system design approach.

@NitinPatel-ld5qd 4 года назад

Great content and lot of work Naren! Sincerely appreciate it. One thing I would like to suggest that we should call out how region servers are formed at the beginning and how the division and distribution of spherical earth is done across region servers shown in DISCO as part of the ring.

@mallikarjunb6143 2 года назад

Nice and Simple presentation. Thanks a lot for this topic and a lot of details. Well, thought of a video. I was able to easily grasp it.

@nkanugodswill6301 4 года назад

Great Video. But I'm still not an IT person. So how much will you charge me to build an app like Uber?

@apidas 3 года назад

can you start or explain them from scratch? you already start with a complex system and you didn't justify for why you're using these components. you just jump into the fun parts

@nabhavlogs371 3 года назад

But no SQL databases aren't a smart choice, if our systems are reqd heavy. How is the company countering this?

@raanonyms7926 4 года назад

This is posted in 2018, and I am watching this now! Shame on you internet :p

@MinhHTRAN-qs4wn 5 лет назад

Very helpful video, thank for sharing. Let's continue with another system design architecture ^^

@NilanshuSharma1 5 лет назад

Appreciate you taking stuff from real engineering blogs, instead of discussing a hypothetical design. Thanks for the effort!

@kaushaldawra3527 3 года назад

Unstructured content. It should start with what problem we are trying to solve rather than directly demonstrating the whole interaction between 20 components.

@sleaxxy Год назад

Thanks a lot for the useful information. The video is from 4 years ago. Do you have more recent information about this system design? I supose several things must be different now, according to the evolution of the system.

@sergiebalzary3861 3 года назад

Please give me link documentation of google extra library map. Thanks

@tippusultan1255 3 года назад

I think we need more logical explanation of why each component is in place. not just explaining what each component does. in a real interview set up we should come up with the design and not explain a laid out diagram. I feel it would be more helpful that way

@chrisding6412 2 года назад

It seems not make sense to me that you already have websocket, why you still need to send the location to Kafka. you can directly send the location to the demand and supply service

@jrwang537 3 года назад

I still dont understand, how does the driver app itself can be as the data source. Do you mean that, if the data center fail, then the driver app can give its own data to the back up service, so that back up service now has the data to finish the trip? But if so, why the driver app still need to call the service? It has the data to finish the job, and it can just call itself?

@sanketh768 3 года назад

I saw this written at multiple places, which says grokking system design. Does anyone know what that means?

@yoganandaiyadurai9474 4 года назад

Very well explained and the clarity is so good. Thanks very much.

@bobbysugianto5744 5 лет назад

perfect broo! you really amaze me! waiting for Instagram system design :D liked and subscribed :D

@ruhinapatel6530 5 лет назад

U made it look so simple..Thanks a lot..You've got a subscriber

@neilarmstwrong6914 Год назад

"Building schemaless that is built on top of MySQL" ?

@k.manideep2543 5 лет назад

Mouthful of information...Thanks for sharing the knowledge...it helped me a lot...Keep sharing more videos like this.

@DrunkenEngineer 4 года назад

Excellent explanation.

@danieltetteh9338 4 года назад

Thanks sooo much for the video , I want to ask if you could make similar video for. Alibaba.com and shopify

@anastasianaumko923 Год назад

Amazing job! You are a rock star in the System Design 🤩😎🎵

@ranjay4473 4 года назад

Outstanding stuff .... it would hv been lot better if u had not tried to fake accent. U got great skills just be proud of it

@catchgautam 5 лет назад

Great work...can you cover Social Graph system design

@gabrielhespanholdossantos8738 2 года назад

Did Uber buy all this infrastructure to have the application running?

@FoodyMomm 6 лет назад

Very good

@shaktinithia 4 года назад

Hi... Would love if you can do video on CRM system design for Telco company

@jinkazamaaa 5 лет назад

Nice Explanation. Please do Python Tutorials.

@TechDummiesNarendraL 5 лет назад

hmm.. Sure

@mohitggarg 5 лет назад

Please explain the design for truecaller as well

@frankservant5754 3 года назад

I doubt you will be able to learn this much in a lecture, that's why we need only those who are passionate about ML to be professors

@anandchiluka7611 2 года назад

Dude, this video is awesome. Thank you very much for sharing !

@pursuitofcat 3 года назад

Can you improve the acoustic of your videos. Use well occupied rooms to shoot than empty ones.

@bharatyoutube81 3 года назад

I have existing taxi booking, need to modify n integrate new features like outstation new bus ticketing

@EldhoseMr 5 лет назад

Expecting a channel like Siraj Ravel

@brajkishore32 6 лет назад

I really liked the coverage you did here... Few things which could be add-on - How does payment system work here? - Sharing live location to others like with family or friends

@jojocabs1913 3 года назад

Hello sir we can make app for you check our readymade on demand taxi app ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-UuP4uck7VNI.html and connect with us by details in description

@batman_1st 3 года назад

Curious why uber moved on from developing its own in house maps to using google s2 library.

@venkatakalyan8330 3 года назад

Great video about uber system design thank for making this video

@anandbabu9219 6 месяцев назад

I am sorry to say this, he is teaching everything from Geeks for Geeks

@rahulsharma5030 3 года назад

Excellent stuff.Just awesome.Kudos for your efforts mate. Doubt : I think we dont need to store the data send by drivers after eveyr 4 seconds i.e their locations in no sql, as it is a transient information and keeps on changing,we can store it is redis or some cache and keeps on serving from their.Even in case cache crashes, the next update will help us to rebuild.Even if we want to store some last previous location,then we can maintain just previous and current location in redis cache and push it to persistent storage after some time say, after 15 seconds or so on.Redis can serve all the requests from in memory.Please let know your thoughts.

@jokyjang 2 года назад

I agree with you. I'm always confused when to use no sql, and when not. But in this scenario, I think a distributed in memory database like redis is a good fit. We want the location accurate and consistent instantly, but no sql's eventual consistency might not fit here.

@exploreHeavenOnEarth 5 лет назад

Excellent explanation of all microservices.Superb job

@fundeos951 5 лет назад

Is there anyone can do this job?i mean anyone can make this type of system app and website ?how much it will cost ?

@RishiPrakash 3 года назад

This is how Uber works, A system design interview would also focus on CAP theorem, Storage estimations, sharding and moreover why to each design decision. ex Why RPC why not Rest?

@jaylee1058 3 года назад

Yeah this is just an unpopular opinion I guess but I think as someone studying for system design interviews, this is not very helpful. To start with an overly complicated diagram and explain shallowly what each component does doesn't really give me any applicable tools to apply to future problems...I appreciate the video but my humble take is that it's not very helpful to me as a resource

@mohammedmohammedalazrg3729 3 года назад

How are you. How can I get you. For business. Like make an app

@AnkitaNallana 4 года назад

Great video - you have explained some key concepts of the whole architecture wonderfully! Thank you so much for this! I have one question though, I couldn't fully understand how the Backup Data Center enables the whole trip with the State Digest stored in the driver/rider's cell phone - what exactly happens in the backup center ?

@himanshugupta174 5 лет назад

Just amazing, I never saw this kind of clear explanation about the system design. Keep it up

@cloud4java 4 года назад

Indeed

@shuvaday 3 года назад

Hi Naren Didnt understand how the trip fraud is being detected.

@shensean1784 2 года назад

Good content. How does websocket works behind a load balancer?

@saagamer2386 4 года назад

Could u upload about basic requirement for bike ride sharing apps

@nirjharpaul 3 года назад

That is not service oriented architecture that is micro service architecture

@GabrielOduori 5 лет назад

Great explanation. Was just wondering if there is any relationship between the S2 library and uber hex spatial indexing when dispatching.

@ShwetassDiary 5 лет назад

Thanks for the information. I wish to know about ping pong ranking system design, can you please provide short explanatory video?

@AbhishekSharma-si8ui 4 года назад

AWESOME

@AbhishekSharma-si8ui 4 года назад

AWESOME

@satindersingh9118 6 лет назад

Sir please you make a video on System Design youtube. Like how they store huge amount of data, how homepage for each user is maintained, how trending page is maintained etc

@TechDummiesNarendraL 6 лет назад

Satinder Singh sure, I am working on Netflix system design now(video will be available soon), sure I will do RU-vid system design too once after that.

@satindersingh6380 6 лет назад

Thankyou sir

@spk7159 6 лет назад

@@TechDummiesNarendraL brilliant video sir

@tobechukwunwatu848 5 лет назад

Yes, pls make such video

@sctm81 4 года назад

Yeah ... I'd like to see someone come up with this whole thing on the fly during a 1h interview ...

@Seraph1502 4 года назад

Interviews are used to grade multiple candidates. Everyone has to do some system design in interviews, so you don't have to come up with this whole thing on the fly. Just be better than other candidates.