Correction: An earlier version of this story incorrectly described the decision in the United States v. Windsor case.

Pratik Shah, the leader of Akin Gump’s Supreme Court and appellate practice group. He joined the law firm after five-and-a-half years as an assistant to the Solicitor General. (Jeffrey MacMillan/Jeffrey MacMillan)

Pratik Shah’s fourth day on the job started out as a casual meet-and-greet with a handful of in-house lawyers over catered sandwiches last September.

Lunch led to chatting, which led to talk of a class action lawsuit the company was trying to get dismissed. Shah — who had just joined Washington law firm Akin Gump that week as co-head of the Supreme Court and appellate group — mentioned a statute that might work in their favor. The in-house lawyers were so impressed they asked him to argue that part of the case before the 8th Circuit Court of Appeals just five days later, a timeline nearly unheard in the world of big law and the corporations they represent.

“It was supposed to be just lunch,” said Shah, who declined to name the company other than to say it is a longtime client of the firm (but one that had been using another law firm for this particular case). “It turned into a working lunch for me.”

It was Shah’s first taste of law firm life and the unpredictable ways that business can flow in. He had just wrapped up five-and-a-half years as an assistant to the Solicitor General, during which he argued 13 cases before the Supreme Court and briefed more than 25, including the landmark United States v. Windsor, which made it unconstitutional to withhold federal recognition of same-sex marriages performed in states where it is legal.

Supreme Court work is not a major revenue-driver at law firms, but it does lend a certain prestige and marketability, especially to a firm like Akin Gump that brands itself as a premier Washington institution.

“It helps us recruit the best attorneys,” Shah said. “It gives comfort to clients that even if they’re not going to end up before the Supreme Court, we have expertise of that caliber ... As a pure revenue matter, it’s not the biggest for the firm, but in terms of importance to the client, it’s shaping law for the industry and the country, which is why it has importance for the firm.”

More than half of the work the group does is representing corporations in cases that go before state and federal courts of appeal. The other half is split between Supreme Court work and what Shah calls “broader legal advice,” where he and the group’s dozen other attorneys offer companies and trade groups analysis on legal issues that the courts are weighing.

Shah worked closely with his predecessor Pattie Millett, a star lawyer who has argued 32 cases before the Supreme Court, the second-highest among any female attorney. Millett was nominated last summer to serve as a judge on the U.S. Court of Appeals for the D.C. Circuit, and for the first three months Shah was at Akin Gump, they went together to meet with clients, not knowing when or if the nomination would go through. When the Senate voted to confirm Millett in December, Shah took the reins as sole head of the Supreme Court practice.

He is now busy making the rounds at law schools and industry groups when they host Supreme Court panels, sharing his insight into how the court works and what the important cases will be. He has spoken at the Institute for Corporate Counsel and George Mason University, and plans to do another at Georgetown Law this week.

“You never know who’s in attendance at these events that may have an issue that’s on its way to the court, and you stick in their head,” Shah said. “And it’s fun for me. I enjoy doing them because it’s talking about the Supreme Court, which is something I would do for free.”