Philipp’s Playground in the Cloud

17 Feb 2021

Selfie Challenge

My family and I thought about a way how to get out again more and be more active after Christmas so we came up with this idea of a Selfie Challenge for the month of February where everybody would take a selfie if he or she would be taking a walk outside or do any kind of sports indoors or outdoors. Initially I collected all pictures and updated the leadersboard but when I had a long weekend last week I came up with this serverless application to take care of all that. I mainly used Twilio Functions as well as their programmable messaging products to receive the pictures via Whatsapp. A function on Twilio would then get called which stores meta data about the picture in a DynamoDB table in AWS as well as dumps the picture into an AWS S3 bucket. Another DynamoDB table representing the leaderboard gets then updated and finally a simple html page it being put together (stored in AWS S3 and served through AWS Cloudfront) listing all pictures as well as the leaderboard. In order to keep everybody who is participating in this up-to-date, a SMS is being sent out to everyone as soon as somebody posts a picture. I am quite pleased with the result and it was interesting to see how the functions plattform in Twilio is working. The most costly component of all this is actually sending out the confirmation SMS’es.

Selfie Challenge Architecture