Kapil Gupta - System Design Tutorial

Design Dropbox or Google Drive

In this Article, we will learn "How to Design a Cloud Storage Service". This will help you understand how such services work behind the scenes and help you answer system design questions like "How to Design Google Drive", "How to Design Dropbox" or "

High Level Design

Design Twitter

Twitter is one of the largest social networks where users can post and read tweets ( short text messages with 140 character limit) along with photos and video support. Users of the Twitter service can also follow their family, friends, or celebrities to get the latest updates about them. In Twitter,

High Level Design

Design Notification System

A notification system is a system to send notification alerts to the users. Notification Alert is a piece of information used to provide some updates to the user for example - updates about the ongoing order, new offering, meeting reminder, bill due alert, OTP notification, etc. Notification systems are an

High Level Design

Design URL Shortener

URL shortening Service creates a compact version of a long URL called tinyURL or shortURL. These URL's can be shared as an alias to the long URL and when someone hits this shortURL they are redirected to the original long URL. Benefits of short URL includes more readablity, convenience to

High Level Design

Yelp System Design

Yelp is a platform for crowd-sourced local business reviews and listings. Locations like restaurants, bars, and other businesses have dedicated pages, where users can read or submit reviews and ratings. Businesses can provide information about themselves on their pages so that people can discover their services and timings. In addition

Concepts

WebSockets

WebSockets is essentially a transport layer built on the top of the TCP/IP Protocol. and provides a persistent bidirectional communication channel between a client and a server. The initial connection is established similar to a normal HTTP request and then upgraded to a lightweight and real-time bidirectional channel which

Concepts

SQL vs NoSQL Database

A key aspect of any Large scale system is the ability to handle a large amount of Data. A Database is used to persist information that will be useful later on. Broadly there are two types of database categories available to store the data and those are SQL or NoSQL.

Concepts

Scaling

Scaling means increasing the system capacity to cope up with increased load for example number of requests or handling more data. Need for Scaling If our system is currently handling 100 requests/min and suddenly the traffic increases to 1000 requests/min, even though our system might be able to

Concepts

Rate Limiting

Rate Limiting means to throttle the number requests to your service from a particular source (user, device, IP, location, etc) to some maximum limit. The requests submitted over the limit are either immediately rejected or they are delayed. Rate limiting allows us to create resilient services, that can handle various

Concepts

NoSQL

NoSQL Database refers to Non Relational database, In contrast to a relational database where data is stored in well defined tabular relations and Structured Query Language is used to access data, NoSQL database uses different mechanisms for storage and retrieval and generally does not provide SQL based data access and

Concepts

Messaging System

Messaging System is a common approach to transfer data between systems and applications. A producer generates a message containing some information that is transmitted to the consumers. We can do this via direct communication via TCP connection between producer and consumer. However, such a system allows communication between exactly one

Concepts

Load Balancing

Load Balancing means efficiently distributing the network traffic across multiple machines to balance out the load and prevent any hotspots. Load Balancers also keep track of servers which are not functional and avoid sending requests to those machines. When the server comes back up or new servers are added, Load

Concepts

CDN

It’s a network of servers that are distributed geographically and deliver content at fast speeds. It gives quick transfer of static content like files(HTML, js, text, etc.), images, and videos. CDN plays a vital role in designing modern web applications and serves a majority of web traffic in

Concepts

Caching

Caching means storing data into the cache, which is a high-speed low latency data storage. It will store a limited amount of information, that is very likely to be used in the immediate future. Caching layer typically stores the data in memory (or RAM) and hence avoids accessing the secondary

Concepts

ACID, BASE AND CAP Theorem

ACID ACID is an acronym for Atomicity, Consistency, Isolation, and Durability coined by Andreas Reuter and Theo Härder as a set of properties of database transactions that every database storage engine should strive for. ACID compliance guarantees the validity of data in events of errors, hardware, or power failures. Atomicity

Introduction

Back of the Envelope Calculations

Back of the Envelope Calculations or Ball Park Estimations are used to roughly estimate a ballpark figure quickly using approximation and rounding off. This method gives good results within a error range of exact results using precise calculations.