One evening in April 2016, 26-year-old Rachel D’Ruan brought a first date to happy hour with some work friends on the Upper East Side.

Two hours into drinks, she fibbed and told her suitor that she had another work event to attend. She then left for the NoMad Hotel in the Flatiron District to meet a second date for cocktails.

Three drinks later, she told her second date that she had a cousin’s party to plan and headed to a third date: dinner at Wolfgang’s Steakhouse in Tribeca with a man she had met at a networking event.

Afterward, during the solo subway ride to her home on the Upper East Side, she received a text message from a guy she was casually seeing. She quickly changed course to meet him at an Upper West Side bar for a nightcap.

“Seeing multiple people in the same night — that’s how I can eliminate them or pick out the best candidates from that batch,” says D’Ruan, an image consultant. “It allows me to better evaluate and compare each candidate to each other. It’s very ‘Bachelorette.’”

In a city known for its ambitious dating scene, where people compete for the most attractive and successful partners, some millennials are treating the single life like a second career, using stats, spreadsheets and stacked meetings to increase their chances of finding love.

‘Seeing multiple people in the same night … allows me to better evaluate and compare each candidate to each other. It’s very “Bachelorette.”’

D’Ruan says the demands of her actual career — the one that pays the bills — gave rise to her workmanlike approach. With only two free nights a week, back-to-back dates were a necessity.

This technique, however, can backfire.

Last week, Justin Schweiger, a project manager based in Washington, DC, achieved viral infamy when he scheduled six consecutive dates in the same bar. The women ended up accidentally bumping into each other, then angrily ditched the guy and hung out together instead. The group left him with the tab.

Lisette Pylant, a 26-year-old office manager who was one of Schweiger’s dates that night and tweeted the play-by-play, tells The Post that the revolving-door approach erases people’s humanity. “With online dating, it’s very easy to fall into that idea that this person isn’t real. I haven’t met this person so I don’t owe them anything,” she says.

Pylant’s views echo a 2012 incident in which an investment banker named David Merkur created an elaborate spreadsheet of 12 women he was dating, ranking their appearance on a 10-point scale. The file went viral as a prime example of some banker bros’ piggish attitudes toward dating.

Now in a relationship, D’Ruan says she never ran into problems with her dating style.

“I felt like I’ve always been very honest with the people I’m seeing,” she says. To keep her ducks in a row, she wrote appointment notes in her calendar that included each date’s initials and reminders of what they previously discussed.

Still, feeling at ease can be challenging with a businesslike mindset. Jason Feintuch, a 31-year-old East Village resident, says he tends to treat dates like job interviews.

“It’s work — you gotta be engaged, you gotta listen. You can’t sit back and relax,” says the corporate strategist, who for a time was going on three dates every week. “[Corporate] strategy is a way of life. It’s how my brain works, so I approach things with strategy.”

For optimal efficiency, Feintuch tries to keep his date spots to within a five-block radius of his apartment, to cut commuting time. He also organizes his dates’ names in his address book with notes on their history.

“It’s bad if you go on a second date and refer to a story from a first date with someone else,” says Feintuch, who admits he’s done exactly that in the past before he documented his dates.

For singles like Caroline Volz, the clock is always ticking.

“Highly successful women are really focused on their careers,” says the 24-year-old fashion buyer. “We don’t have a ton of time to waste.”

Instead of playing coy, Volz has a specific set of questions she asks her matches on every first date to help pin down their career goals, hobbies and interests.

“I’ve learned you have to be straightforward,” she says. “It goes back to this whole idea of time efficiency.”

On top of meticulously scheduling her rendezvous, Volz continually updates a note on her phone with her dates’ qualities and a graded assessment of whether they’re worth seeing again.

Dating expert Monica Parikh, founder of School of Love NYC in Prospect Heights, says a data-driven approach can be useful if done correctly.

“A good way to use a spreadsheet is to focus on values. Write down what you really liked about your date and what you didn’t like,” she says. “But a spreadsheet that ranks people like they’re in a personal beauty contest — that’s offensive to me. It says you’re not dating with the mindset of meeting a person. It says you’re feeding an ego.”

Parikh isn’t a fan of scheduling multiple dates on the same night, either.

“It’s overly pragmatic, and emotionally not enough,” she says.

Feintuch recently cut back his first dates to one a week and now prefers to find matches through Wing, a dating app that lets users’ friends play matchmaker.

“I’d like to settle down,” he says. “It’d be nice to find quality over quantity.”

As for D’Ruan, she met her current beau on Bumble last summer, and after a year of dating, the couple has decided to go exclusive.

“He doesn’t demand a lot of my time, and he’s very understanding of my networking habits and crazy schedule,” she says. “We have a mutual understanding and a mutual appreciation for our specific work-life balance.”