A Three-Tier Web Application Using REST

It should be safe to say that the vast majority of developers know what REST is. A three-tier web application consists of the following:

• Presentation layer (HTML and CSS)
• Business logic layer (application code)
• Data layer (Relational Database Management System or another type of data store)

The three-tier web application is extremely well known and one of the most common designs on the web today. Readers are likely familiar with this design when thinking about a web application's static content (that is, HTML, JavaScript, and CSS) which are served from a content delivery network (CDN), which talks to a RESTful API hosted on a web server, which, in turn, talks to a database.

In this chapter, we will go through the process of building a three-tier web application using HTML, JavaScript, and CSS for our presentation layer, a REST API for our business logic, and a Postgres database for our data tier. Most importantly, and keeping in line with this book, this will all be accomplished using serverless technologies or services where you do not need to manage servers yourself.

By the end of this chapter, you can expect to know the following:

• How to author a REST API using Amazon Web Services (AWS) Lambda and Python
• How to build, manage, and deploy static assets to a CDN
• How to create and maintain an RDS Postgres database
• Options for designing RESTful APIs, including different languages, frameworks, and layouts of functions
• Static asset life cycle management and caching for optimal performance