Hello, Sarah
Kudos, your article is super didactic and inspiring!
A few months ago, I also created a twitter bot with a design similar to yours, the @UraniumStockBot, Code.
One approach that could be better is using serverless products. As your application has a scheduler that triggers it, you don't need it up and running full-time. This way, you can save money and resources.
For example, I deployed the application at Heroku and used EasyCron to trigger it every half hour. Between one each trigger, the instance is turned off.
I hope I have opened your mind to new ideas. =]
Bests