How we built the prototype for Split by GroupMe in a weekend using Balanced
blog.groupme.com
blog.groupme.com
This is great advice. While it's important to push your limits and learn new skills -- hacker culture often looks very favorably on jacks-of-all-trades, or "learning to build x" with no prior experience -- it's also important to know exactly what you can bring to the table, and then deliver quality work, in whatever it is you do best.