Well, not sure if it works for skilled devs, but… Let’s try to decompose the problem:
- Attract enthusiasts from external platforms (external action).
- Convert enthusiasts to contributors (internal action).
External part
There’s a small trick to get the relevant attention to a project for free. The goal is to create some artificial challenges in a manner of “a newbie asking for advice”. It might be a short code snippet with some errors, or a question describing a dev-specific problem. Even real tickets from fork issues if they are interesting. Those “baits” should be posted to any relevant platforms: Stackoverflow, WP forums etc. Each question should touch CP ecosystem. No spam or advertising, just mentioning it in context. To give an answer, people would refer to CP’s docs or Github, discover a project detailes etc. If the bait is interesting enougth there’s a good chance to attract some enthusiasts to dive deeper.
Acting from a “newbie” position provides great results. It lets people show their skills, knowledge and qualification. It generates enthusiasm. A good comfortable background for joining and contributing.
Internal part
People need a simple and obvious point of focus. It’s hard to make a first step when you join a totally new community. The “dev todo” on Github is a bit messy and overflowed for a first step. (By the way, same trouble as with CP download link: too many clicks, hidden. I’d offer to make a separate invitation page and represent it by large banners on “Get involved!”, docs section and everywhere else :).
Maybe there should be a separate “welcome” todo list containing a section with simple warm up tasks (15-60 minutes) organized in a common way (just a list, maybe the tasks filtered form Github by slug “good first issue” or something manual in Jira/Trello/Asana. The idea is to make a friendly sandbox-alike environment without dropping newbies right into a messy fight. Just to remove “neophyte syndrom” and frustration.
One more note about Github etc. WP used to be a favorite CMS for solo webmsters and freelansers for years. So there is a large group of users who are skilled in building custom themes and plugins, but have a lack of experience in collaborative development. Those people are the most promising volunteers. But they (we) need a small adoptation. Maybe a short guide or a video with 1 example of completing a random task, showing the whole process (not coding skills, but the procedure). It also helps when experienced community member tells about tools. agreements, best practicles. It may sound funny, but 1 example could be enougth to convert solo player to a contributor.