Some time ago I developed a reservation system using AWS CDK. Potential customers can visit a website that contains a calendar, click on a date, click on a time and finally, enter their email address. A confirmation email will be sent to their address right after the reservation.

I built this infrastructure using an S3 bucket (static hosting), a Lambda Function, a DynamoDB table, an API Gateway and Simple Email Service. CloudFormation is used for the deployment of the mentioned constructs and CloudWatch is used for monitoring and logging.

The flow of a reservation submission is as follows:

1. User accesses the static website hosted on S3. 
2. User submits a reservation through the website.
3. The submission is sent to the API Gateway endpoint. 
4. API Gateway triggers the Lambda function.
5. The Lambda function processes the reservation, writes it to DynamoDB, and sends a confirmation email via SES.

This entire solution only costs a few cents a month at this point.

Below you can find an overview of the architecture.

I am sharing this partly because I’d like you to see how relatively easy and cheap it can be to build a complete solution like this reservation system. With only a few AWS resources you can create an entire system from scratch that is always available. No infrastructure to maintain.

It wasn’t all unicorns and rainbows though. The thing that bugged me the most during this project was the entire DNS stuff. What a pain that was to figure out.

Shoot me a message if your interested in learning more.