If we are dealing with a read-heavy system, it’s good to consider using a Cache

Rule #2

If we need low latency in system, it’s good to consider using a Cache & CDN.

Rule #3

If we are dealing with a write-heavy system, it’s good to consider using a Message Queue for Async processing

Rule #4

If we need a system to be ACID complaint, we should go for RDBMS or SQL Database.

Rule #5

If data is unstructured & doesn’t require ACID properties, we should go for NO- SQL Database.

Rule #6

If the system has complex data in the form of videos, images, files etc, we should go for Blob/Object storage.

Rule #7

If the system requires complex pre-computation like a news feed, we should consider using a Message Queue & Cache

Rule #8

If the system requires searching data in high volume, we should consider using a search index, tries or search engine like Elasticsearch.

Rule #9

If the system requires to Scale SQL Database, we should consider using

Database Sharding.

Rule #10

If the system requires High Availability, Performance, and Throughput, we should consider using a Load Balancer.

Rule #11

If the system requires faster data delivery globally, reliability, high availability, and performance, we should consider using a CDN.

Rule #12

If the system has data with nodes, edges, and relationships like friend lists, and road connections, we should consider using a Graph Database

Rule #13

If the system needs scaling of various components like servers, databases, etc, we should consider using Horizontal Scaling.

Rule #14

If the system requires high performing database queries, we should consider using Database Indexes.

Rule #15

If the system requires bulk job processing, we should consider using Batch Processing & Message Queues.

Rule #16

If the system requires reducing server load and preventing DOS attacks, we should consider using a Rate Limiter.

Rule #17

If the system has microservices, we should consider using an API Gateway (Authentication, SSL Termination, Routing etc).

Rule #18

If the system has a single point of failure, we should implement Redundancy in that component.

Rule #19

If the system needs to be fault-tolerant, and durable, we should implement Data Replication (creating multiple copies of data on different servers)

Rule #20

If the system needs user-to-user communication (bi-directional) in a fast way, we should consider using Websockets.