BAH offers professional services to companies, mostly via federal contracts. Once BAH wins a contract, they staff the positions needed. Typically BAH is interested in filling these positions with someone who the client will be happy with. Good general knowledge of the position is required, but a contractor mindset is very sought after. A contractor mindset is an understanding that you work for BAH, but you are making the client happy, if the client likes you, you are golden. Since you will typically not be interviewed by the client, you will be interviewed by BAH staff who are trying to get what the client is looking for. If you can come across as confident and sure of your ability, you will do fine. Remember, you are trying to convince BAH you can do the job for the client.