Finding love at first sight isn’t easy, as anyone who’s used Tinder can tell you, but maybe a computer program can spot your soulmate for you. That’s just one part of what the matchmakers at startup Three Day Rule do, but it’s undeniably eye-catching. Clients hand over pictures of friends (or exes) they are attracted to, add a celebrity crush or two, and the system pulls out some potential matches in its system whose jawlines, eye shape or other features fit the type.

Callie Harris

“It’s a pretty simple drag-and-drop system,” TDR matchmaker Callie Harris explained to me in an interview. “It helps streamline the process but there’s a lot more to matching people up.”

Considering there are around 10,000 people signed up for TDR in the D.C. area, any kind of streamlining is helpful. It’s free to become a candidate, but if you want to guarantee getting dates, it’s $4,500 for the three month package, which includes assessments, matchmaking and TDR event access, or $6,000 for the six month package, which includes either photography sessions, date coaching or styling help.

For that kind of investment, Harris devotes a lot of hours to each of her 26 clients. During the day she often sits in a coffeeshop, interviewing potential matches for her clients and going through online profiles in between meetings for more possibilities. At night, she’s often found out at bars and events telling people about TDR and urging them to sign up.

“They do sometimes think I’m trying to pick them up,” Harris admitted. “I wear this [fake diamond] ring to show I’m not.”

After they sign up is when the technology comes into play. As for whose pictures her clients give her, Harris said there’s a lot of pictures of exes or screenshots from dating apps. The celebrities chosen are sometimes predictable; Jennifer Aniston, George Clooney and Ben Affleck are all popular, but she’s sometimes been surprised by just who pops up.

“People have Bieber fever for sure,” Harris said. “Idris Elba turns up a lot. I get a lot of actors from Game of Thrones also.”

If that were all that was needed, Harris and her fellow matchmakers would be entirely unnecessary, but the face-matching is only part of the process. When she interviews potential dates for her clients, Harris asks all kinds of questions, but it’s style as much as content that can matters. Someone’s interests, lifestyle and kind of relationship they’re looking for matter, there’s also the question of how they behave during the interview, what kind of images they pick for their profile, all sorts of subtle signs that Harris can use as ways of measuring their compatibility with her clients.

“It’s not always obvious who the best matches are,” Harris said. “I’ve set up about a dozen long-term relationships since I started [last January]. I know what to look for.”

The clientele is diverse and has included professional athletes and other public figures. In one afternoon, Harris met with young professional woman in her mid-20s, a male doctor in his 30s and a man in his 60s whose children are all grown. Not exactly a narrow group, although generally there’s a tilt toward more women than men in the database. And Harris has ideas for matches for all of them, even if they don’t always exactly like the celebrities the clients pick out.

“The secret sauce is understanding people,” Harris said. “Matchmaking can never be entirely empirical.”