Ethereum Gas Price Notifier
Transactions on the Ethereum network require "gas", and the price of gas represents the aggregate demand for Ethereum blockspace at a given point in time.
Like most things in crypto, the price of gas is extremely volatile, so it is useful make transactions when gas is cheap to save money, as well as to avoid making transactions when gas is expensive unless really necessary!
This is a simple program designed to run as a regular background task on AWS Lambda, every hour or so. It queries the current recommended gas prices from etherscan and stores the data to DynamoDB. Then, comparing to historical data, it decides if the current gas price is relatively cheap or expensive. When the categorisation of gas becomes Low or High, it triggers an email notification to be sent.
By considering the standard deviation of past gas prices, it is able to adjust to changing volatility in the prices and avoids needing to program and update arbitrary price targets.