Mastodon's search isn't great. If someone you know joins, give them a boost. It's helped me find many of the developers and apps we cover on @macstories, but I'm sure I’ve still got many folks to track down.
Thanks for the recommendation of various tools to find Twitter follows here. I used one myself. I like a good automation tool as much as anyone and they help, but aren’t a replacement for help from a friend or a personal recommendation of who to follow.