Most digital agencies are started by experts, do-ers, from one discipline. People who’ve done the work for other agencies at a high level, client-facing, and thought they could do it better. Or just didn’t want to work for someone else, in someone else’s stodgy agency, any longer. A senior agency tech lead takes the leap, brings some buddies, maybe a client, and crafts a new flavor of tech shop that excels at his or her area of focus. If they do well, they start pulling in more people just like them, then complementary freelance specialists in other…