When to hire a UX agency and
when to build your own UX team
If you need to get going now or are tackling a complex UX problem, partnering with a good UX agency makes for a wise move.
Otherwise, if you have longer-term goals to build a user-centered culture, have the money, and access to a high-quality talent pool, you should probably hire.
All in all, though, answering this question is not so simple. The two types of UX teams are not necessarily non-complementary. Rather, it's a correlative, often reciproal relationship, in which in-house and agency UX teams help and support each other.
If you are just setting out to build UX thinking within your team, hiring externals temporarily can be of help in building not only great products but also a customer-centric design culture. We at UX studio facilitate UX design training courses for teams. Here we teach them the basics of a new way of building digital products.
Extending your existing team can be a good idea for a multitude of reasons. Not only is it faster and easier to access these experienced professionals but they also bring a great amount of external knowledge that your team can later leverage.