Dr. Philip Maymin and Dr. Jie Tao close out a two-part conversation with Margarida Sacouto and Sheila Green, graduates of Fairfield Dolan's MS in Business Analytics and AI, who spent a semester consulting for Synchrony Financial. This time: what they built, and why it took so long to start.

Sixty to seventy percent of the client work was spec-driven development, not code — a constitution, then a spec, then plans and tasks, in plain English, before anything ran. Green's group logged seven versions. Sacouto's pitch to executives: three days of every five-day week lost to data prep, cut to hours, and models scored better on her team's engineered features.

Maymin presses: isn't that just vibe spec-ing? Tao won't have it. Vibe coding, he says, is prompt and pray; auditing, red teaming, and persona challenges are the opposite. He abandoned test-driven development as models gained autonomy — the model becomes both judge and player, writing weak tests and gaming them. Maymin floats checkpoint-driven development as the successor; Tao counters with a living deliverable, not a living document.

The classroom rule follows from the practice: "I don't think it's responsible to teach students something that I don't use every day." The tool changes every semester — n8n on the original syllabus, Claude Skills by the end — and the philosophy doesn't. "We teach you the philosophy through the tool."

At the Institute's one-year showcase, senior Synchrony executives fill the room, the projector fails, a teammate away at an NCAA lacrosse tournament appears on video, and Green jokes about it. Synchrony asked for the students back.

"I'm becoming the bottleneck. I realize that. But I'm still slowing it down." Synchrony's side lands next episode.