* Assuming a mixed stack, the ability to communicate to with the other devs is important. Often front end devs think they know everything about the product and

* Assuming a mixed stack, the ability to communicate to with the other devs is important. Often front end devs think they know everything about the product and don't get on with the back end apis and vice versa. * Understanding of things outside their scope such as databases, server setup and deployment * Good knowledge of a couple of frameworks, but the flexibility to pick up others quickly too and not constantly complaining if they have to deal with legacy code or frameworks they don't like! * Communication, humility and the ability to teach or mentor more junior staff * Knowledge of base JavaScript and programming in general should go without saying. Ability to do reasonable design / css / html even if that's not their area * Remember one persons expert is is Brendan Eich or Ken Thompson. Another persons might be any career developer with 3-5 years experience!