"Let's do a deep dive on this." The phrase appears in meeting invites, project plans, and casual conversation. It signals thoroughness, rigor, and a willingness to go beyond the surface. It has also become so common that it no longer reliably signals any of those things.
What a deep dive is supposed to be
A deep dive is a thorough, detailed examination of a topic. It goes beyond the summary level to examine the underlying data, assumptions, and mechanisms. It takes time. It requires preparation. It produces specific, detailed findings.
This is a real and useful activity. The phrase is not the problem. The overuse is.
What a deep dive has become
In many workplaces, "deep dive" has become a synonym for "meeting about." "Let's do a deep dive on the Q3 numbers" often means "let's have a meeting where someone presents the Q3 numbers." The depth of the dive depends entirely on the preparation of the presenter and the quality of the questions asked.
A meeting is not automatically a deep dive because it is called one.
The shallow deep dive
The shallow deep dive is a meeting that is called a deep dive but does not go deeper than a standard review. The slides contain the same information that was in the summary. The questions are answered at the summary level. The meeting ends without any findings that were not already known.
This is not a failure of the participants. It is a failure of the framing. If you want a deep dive, specify what depth means: what questions need to be answered, what data needs to be examined, what level of detail is required.
When to use the phrase
Use "deep dive" when you mean a genuinely thorough examination that goes beyond the summary level. Specify what that means in practice. "I'd like a deep dive on the customer churn data — specifically, I want to understand the top three reasons customers are leaving and whether there are patterns by segment" is a deep dive request. "Let's do a deep dive on churn" is a meeting request.
The alternative: Instead of "deep dive," say what you actually want: "a detailed analysis," "a thorough review," "an examination of the underlying data." These phrases are more specific and set clearer expectations.