What incentives do mainstream brokerages have to building public APIs? It seems to me data asymmetry is the name of the game in Wall Street and it’s no different for retail brokers.
Are you actually doing this for a production app with income you rely on? Because Heroku has horrendous uptime these days. Lot's of random emergencies on both worker and web dynos. Don't forget you share routing with thousands of other apps too so expect random hiccups there too. It's easy to give this advice but does not scale well with complexity.
We are using Twitter's Streaming API and go through tweets as they come in. Then we figure out the song/artist information and then aggregate that at the end of each day.
That's a good point. So far most of the top songs just shuffle between each other. New songs start appearing towards the bottom of the list. Maybe a "random" feature could help with this?