System Design Interview Guide for Software Architecture

Here, we'll look at which DB shall be used in what scenario.

We'll start off with simpler use-cases and towards the end, we'll look at some complex real-world scenarios that require a combination of multiple databases to be solved.

One of the most common System Design Interview questions. If you are interviewing at 5-6 companies, one of them is definitely going to ask you this.

So let's look at how to design a scalable URL Shortner service like TinyURL

Specifically somethings like:

1. How to make sure that it can scale up to billions of requests

2. It should give us unique short URLs with absolutely no collisions

3. Some mathematics on how to choose the right length of the short URL

4. And some more...

Another very common interview problem: how can you design a Hotel Booking system, like Airbnb / Booking.com

After watching this, you'll be able to answer some key questions like:

1. How does Airbnb handle millions of its hotels and users

2. What would you do if you have just one room and multiple users trying to book it

3. If you were building a hotel booking system, how can you go about building it

4. Can you put in dynamic pricing based on demand/supply

5. And many more...

In this video, we'll look at some key aspects of the System Design of an e-commerce application like Amazon, Walmart, Flipkart.
We'll try to answer some questions like:

1. How to scale it to millions of users

2. How does their recommendation engine work

3. Where do they store all the user data

4. How can you build a system of your own that scales up to Amazon's level

5. And many more...

We'll now look at how can you design a chat application, something like Whatsapp, telegram, etc.

Key aspects that we'll look at are:

1. How can we make it scale to billions of users

2. is it possible to do it without storing the chats on the servers?

3. How do you make it real-time or at minimal latency

4. Can there be race conditions in chat systems

5. How do you make it work for a group chat

6. And the list goes on...

Let's look at how can you build a scalable notification sending platform, that can be used to send notifications to billions of users.

This is usually always a part of your system design because usually, irrespective of what you are building, you'll end up having a system to notify your users about their orders, any messages they have received, their bill, or if their cab has arrived.

After watching this, you'll be able to answer some key questions like:

1. If your product has billions of users, and you need to send out billions of notifications, how to do that

2. How to make sure important notifications are always received

3. How to prioritise and choose which mode to use for sending notifications

4. How to make sure you are not bombarding your users

5. And many more... 

Here, We'll look at how can you design a cab booking system, like Uber, Ola, Lyft, etc.

After watching this, you'll be able to answer some key questions like:

1. How do you find which is the best driver for a particular ride

2. How can we make it scale to billions of users and millions of drivers

3. How can you show the real-time location of a driver to a user

4. What's the most efficient way to store the cab location coordinates

5. And many more...

One of the most common System Design Interview questions. If you are interviewing at 5-6 companies, one of them is definitely going to ask you this.

Here, We'll look at how can you design a Social Network, like Twitter etc.

Key aspects that we'll look at are:

1. How can we make it scale to billions of users

2. How do you make sure that you can minimise the latency? People don't want to wait and see a loading sign, anymore.

3. What if someone posts objectionable content. How do you find it out

4. You have a massive number of tweets coming in every second, how do you handle that much data

5. How do you handle the images that people upload

6. How can you prioritise a user's view, and show them the tweets that they would like to see

7. And many more...

We'll now look at how can you design a Social Network, like Facebook / Instagram.

This is more of an extension of Twitter and this system can handle 10x more scale.

Key aspects that we'll look at are:

1. How can we scale the Twitter system even further

2. How can we do it without using so much of memory (Caching is expensive)

3. What kind of additional analytics can you do

4. How do you monitor your systems and make sure you have a great uptime

5. And many more...

We'll look at how can you design a Video Streaming application like YouTube, Netflix, Amazon Prime, Hotstar, etc.

Key aspects that we'll look at are:

1. How can we make it scale to billions of users

2. Where would you store the Exabytes of content

3. How do you serve video content to the users at minimal latency

4. How do you make it work on low-end devices

5. Can you make it work for people with low-quality internet

6. What if someone uploads objectionable / Pirated content. How do you find it out

7. And the list goes on...

Let's look at how can you design a video conferencing system

After watching this, you'll be able to answer some key questions like:

1. Which protocols do you want to use for building such a system(it's not just UDP)

2. How can you establish a Peer to peer connection between two users

3. Video data is huge in size, how do you transmit the terabytes of data that the users generate

4. How can you make it look real-time and avoid lags

5. How can you handle when multiple people are on a call

6. And many more...

The same design can be used to design any Video chatting platform like Whatsapp, FB messenger, Zoom, Skype, etc.

In this video, we'll look at how to design a Navigation app, like Google Maps, Apple maps.

We'll try to answer some questions like:

1. How to optimally calculate the route from Point A to Point B

2. How to store the enormous amount of data that's required to power such a system

3. How can you make it available to billions of users

4. How do you handle the ever-changing geographies, new areas, new roads, etc

5. How additional can you do with this data. Remember, location data is a goldmine of information

6. And many more...

This video covers some do's and dont's in a System Design interview.

In this practice test, we’ll answer a few questions based on some of the topics that we covered in the course to assess our grasp of them.

Some of the questions in this practice test would have multiple correct answers.