APIs open up a lot of unique opportunities that require engineers with diverse skill sets. You can see this in both the engineering and evangelism roles below from Stormpath, Xero and Klout. Being a polyglot is as important as ever, especially when the technology you're building by definition can work with everything else.
Developers are often finding themselves as API providers in addition to consumers. The same is now true for me with my project, BuildaSearch. I recently released a BuildaSearch API for deeper site search integration, moving away from a more plug-and-play approach I took earlier on.
Wowzer, video screening/interviewing provider, announced the public release of the first Wowzer API. Wowzer believes its video screening platform (as an alternative to phone screening) reduces candidate screening time by 75%. Recruiters and employers can evaluate and respond to applicants in a time and manner most beneficial to their organization. Extending the Wowzer platform via API allows recruiters to integrate the Wowzer features into existing hiring processes.