This Platform.io project shows how to connect your ESP8266 to AWS IoT.
Don't forget to add your certificate and key to the data directory
and upload your spiffs (data) folder using the following terminal command:
platformio run --target uploadfs
For more information, check: https://michaelteeuw.nl/post/184650388202/connecting-an-esp8266-to-aws-iot
This examples uses an insecure SSL connection. Do not use the MQTT connection for sensitive data. Keep in mind that the S in IOT stands for Security. ;)