In English, when we say someone is "talking shop", we mean that they are having a conversation about a particular trade or skill that they're familiar with (usually because it's their profession), with someone else who is equally familiar with it. In this kind of conversation people use the language they normally would while working (i.e. they wouldn't use layman's terms or dumb-down their word choice like they would when talking to someone outside the profession). When people are talking shop, it is (by definition) rather hard to understand by someone who doesn't know about said profession.
Is there anything similar to "talking shop" in Japanese, while keeping the slangy tone?