Kotter's 8-step change model

Software Architectures ( 1-tier, 2-tier, 3-tier and n-tier architecture)

1-tier - Monolith

2-tier - client-server architecture

Transformational leadership and performance (DevOps TV)

Serverless vs. PaaS vs. FaaS vs. BaaS (Blog.neap.co)

• Platform as a service
• Platform as a Service, allows you to focus on writing code without worrying about the underlying infrastructure. Beyond writing code, the only extra complexity might be around deployment and configuration (e.g., automatic scaling rules, geo-replication).
• Serverless
• Like PaaS, Serverless focuses on writing code without worrying about the underlying infrastructure, but it does it with even more deployment ease and less configuration. 
• Overlaps PaaS and falls into the following two categories
• Function as a service
• Function as a service is a serverless product that hosts a piece of business logic (with usually a small footprint like resizing an image or sending an email). FaaS is well suited to build event-driven architecture. 
• Backend as a service
• Backend as a service is a serverless backend ( e.g. DB hosting) that is a highly available backend that can be set up with barely any configuration and can scale almost infinitely. Once created, the developer focuses on deploying code or data only. 

Evolution of Serverless

On premise

Mix of Cloud and SAAS

Mix of Serverless and SaaS

Microservices vs. API (Edureka)

Microservices

Monolithic Architecture

• Front end, back end, business logic all reside in a single code base. 

Example Scenario is that of Amazon Market. 

In the case of Monolithic Architecture,

Microservices Architecture

In the case of Microservices Architecture,

• In case of a Microservice architecture, all the three functionalities - customer information, products available in cart and All the products available, can be put in three different services. 
• Service A - Customer information
• Service B - Products available in cart
• Service C - All products available
• Composite Microservice - will take data from all the three services above and display it to the customer. 
• 
  

Microservices or Microservices Architecture is an architectural style that structures an application as a collection of small autonomous services, modelled around a business domain. In a Microservices Architecture, each service is self-contained and implements a single business capability. 

APIs

Application Programming Interfaces most commonly known as APIs is a way to ensure two applications communicate with each other to process client requests. 

HTTP Methods used by APIs

APIs use the above methods to communicate between the client and the respective functionality / feature of the app (service).

Where are APIs used in Microservices?

API interfaces between the client and the Microservice. 

Summary

Microservice is an architectural style through which you can build applications in the form of small autonomous services.

APIs are set of procedures / functions which allow customers to use the underlying service of an application.