The Aviary photo editor was a truly fun product to build and maintain. It was pivotal in a couple of ways -- it pushed the boundaries of what could be done in a Web browser without a plugin installed, and it marked a transition at Aviary from the Flash-based suite of creative tools to the HTML5 and native mobile offering that propelled the company into an entirely new business.
At the time of writing, the Web-based photo editor is integrated as a third-party JavaScript widget in a number of high-traffic websites including Flickr, Yahoo! Mail, Photobucket, Squarespace, and MailChimp, among others.
The biggest challenges involved reaching a very high level of performance, polish, and detail in the user interface, developing tactics to manage a very large JavaScript code base, providing intuitive theming and a modern API to developers, and running as a third-party plugin in an unpredictable landscape.
The highlights of my work included meeting and supporting developers at hackathons (including Aviary's own Photo Hack Day) and seeing their excitement and ideas for the editor.
The end of my time at Aviary was spent mostly building tools to help improve developer experience -- allowing code refactor without headaches (back-filling unit tests) and making sure our partners were not disrupted before a new release (PhantomJS-powered automated screenshot tool).