Following are the links to the site I read while trying to figure out about Amazon Dash.
A simple tear down of Amazon dash.
This post is more focused on Wifi details of Amazon dash.
Components and pinouts of Amazon Dash Button
Dash Hacking: Bare-Metal STM32 Programming. How to disassemble an Amazon Dash button and reprogram its STM32 processor!
Amazon site for dash buttons
AWS IoT Button from Amazon. The AWS IoT Button is a programmable button based on the Amazon Dash Button hardware. This simple Wi-Fi device is easy to configure and designed for developers to get started with AWS IoT, AWS Lambda, Amazon DynamoDB, Amazon SNS, and many other Amazon Web Services without writing device-specific code.
Newer version of Amazon dash.
Setup dash button.
Disassembling the Dash
Beginners guide to using your AWS IoT button
Reverse Engineering the Amazon Dash Button’s Wireless Audio Configuration.