I am always looking for simple advice I can give to API providers to make their developers and would-be developers integration as friction-less as possible. When it comes to making the code available for your API I recommend providing a wealth of samples, libraries, and full blown SDKs for your developers. Also make sure these code resources are as easy to find within your developer portal, as well as being openly licensed and available on your API platform's Github profile.
Adding to this advice I would also recommend that you take the top 10 programming languages and platforms out there, and perform a quick Google search for the key phrase, and see what comes up, on a regular basis. I tend to find interesting conversations around an API when I do this. Inversely it can also provide some interesting signals that an API isn't very active within specific communities, and there probably isn't much existing support.
For me, searching for API [name] + [programming language] or [platform name] = some interesting reflections of activity around an API. I can also imagine that this would provide a way for API providers to learn where the gaps in their outreach are, and give them another way to reach their developers or potential developers--demonstrating that SEO plays a significant role in successful API operations.