AI could eat Big Law's billable hours. Cooley's boss says bring it on.

Rachel Proffitt.

Rachael Wright for BI Cooley has made billions doing what law firms do: hire great lawyers, bill for their time, and keep clients happy.

Artificial intelligence is scrambling that formula.

If machines can do in minutes what once took an associate hours, what exactly should clients be paying for? Rachel Proffitt thinks she has the answer.

On a toasty October afternoon in San Francisco, I met Proffitt for lunch to talk about the future of the global law firm she now leads.

When the check arrived, neither of us knew how much the restaurant paid the dishwasher or how many minutes the chef spent preparing our meal.

We were paying for the experience, not the labor behind it.

Why, she wondered, should legal services be so different? "Clients have never been excited about the fact that it took us 82 hours to do something.

They don't care," she says.

"They just want the outcome.

They want the results." The billable hour is only the beginning.

AI is forcing law firms to rethink how many associates they really need and how those young lawyers learn their craft.

Client relationships are changing as companies use software to get a head start on the work they send to outside counsel.

Some of that work may never reach a lawyer at all.