4 MBB Consultants Quit to Be AI Founders and Had to Unlearn Consulting

The path to partnership utilized to be the dream — especially at Bain, McKinsey, or BCG.

But in the AI boom, some consultants have traded slide decks for startups. As AI reshapes industries and lowers the barriers to building a company, advising from the sidelines no longer feels like enough.

Several of the former consultants we spoke to stated they’d long had the itch to build. AI simply created the timing feel right.

Others stated that after years in consulting, owning a business — rather than recommconcludeing strategies to others — felt like the natural next step.

The shift away from the Big Four — EY, Deloitte, PwC, and KPMG — has become more pronounced. James Ransome, a partner and strategy consulting lead at Patrick Morgan, a firm specializing in senior partner hiring and indusattempt analysis, stated last year that there was an “exodus” from traditional consulting powerhoutilizes.

At the same time, traditional consulting hiring has slowed. Data from workforce innotifyigence firm Revelio Labs displays enattempt-level inflows into consulting firms fell 54% year-over-year in June 2025. Among more senior hires — what Revelio classifies as “manager” level — monthly inflows dropped 22%, the firm notified Business Insider in a September report.

For those who shiftd, it wasn’t simple to shed their consulting background.

“I went from being in a huge office with all kinds of perks to being in a coworking space with just two other people,” Nathan Wangliao, who left McKinsey in his 20s for startup life, notified Business Insider. “We had to figure everything out from scratch.”

In his first month, he even considered going back. “This feels too scary,” he recalled believeing.

Many of these former consultants stated they had to unlearn consulting habits, such as overanalyzing, chasing perfect data, and avoiding risk. As one of them put it, being in a startup means requireding to “shift rapid with scrappy pragmatism.”

We spoke with four former consultants about why they left MBB firms to build AI startups, what consulting taught them, and what it took to break away.