You might not know Jimmy Napes’ name just yet, but he already counts the Kardashian clan among his biggest fans. As a songwriter and producer, 27-year-old Napes—real name James Napier—has been behind some of the biggest crossover dance hits to come out of the UK in the past couple of years, including being Sam Smith‘s collaborator on “Stay With Me,” which the Jenner sisters were all over at the 2014 VMAs. Boiling the kettle to make us both a cup of tea in his quiet basement studio, Napes’ eyes widen as he recounts how surreal it’s been to see Smith become a superstar over in the States. “Over there, it’s like he’s not even a human being,” he tells me. “He can’t walk the streets. [At his Atlanta show] they were singing deluxe songs, like track 14 of the album, and they knew every word from every verse. I had goosebumps the whole show.”

By contrast, Sam Smith fans “don’t have a bloody clue who I am,” Napes laughs. Until now, his success has been as private and as closely felt as the goosebumps under his shirt sleeves, while the artists he’s lent his Midas touch to have been rocketed to an incredibly visible realm. First, he recognized the pristinely powerful vocal talents of a 19-year-old Sam Smith back when the teenager was pulling pints in St Paul’s; after a mutual friend introduced them, Smith came down to Napes’ studio and they wrote the ballad “Lay Me Down” together. With Napes having been taken on by Disclosure‘s management as a songwriter, the Lawrence brothers took a shining to the song, and so the four sat down together to write a song that became the snowball transatlantic hit “Latch.” What came next was a blinding hat trick of three UK numbers ones penned by Napes—Naughty Boy and Sam Smith’s “La La La,” Smith’s “Stay With Me,” and Clean Bandit’s “Rather Be”—as well as co-writing and production credits on Smith’s and Disclosure’s debut albums. Before you could say “overnight success,” Napes was collaborating with Nile Rodgers on a smooth funk jam, writing heartbreak anthems with Jessie Ware, and producing Mary J. Blige‘s career-rebooting The London Sessions in the very studio where he’s currently brewing me a cuppa.

We all know that overnight successes don’t really exist, though, and Napes’ story began long before he first heard Sam Smith sing. As he prepares to release a debut EP of his own solo material, what I’m here to understand is what that magical thread is that connects this string of solid gold hits that he’s quietly put his name to over the past few years. it’s time to ask: who is Jimmy Napes?

Napes is a north London boy through and through, who grew up in the peak years of UK garage while also picking up classical musical training from his parents (his dad is a drummer, his mum a pianist). He idolizes artists like Carole King and Burt Bacharach who built an empire by writing solid, classic hits for others as well as themselves, and in his quest to emulate them he spent his early adulthood earning a pittance while honing his craft. “I was doing my ten thousand hours of just writing,” he says in response my blunt-edged question of what exactly he was up to before he was suddenly writing for the most hyped electronic act in the UK. “I was writing all the time, but I wasn’t having any success with it. I was DJing at the weekend, just for like a job but I wasn’t making any money. I’d make like 100 quid or whatever to see me through, but then I would just write all week. I wrote a thousand rubbish songs, and then eventually five good ones.”

When they came together to write “Latch,” Napes, Smith and the Lawrence brothers were all hungry for an opportunity. “Sam was pulling pints, I was DJing at weddings, the Disclosure boys didn’t have a pot to piss in,” says Napes of that fateful session. “We had that fire in our belly to be like, ‘let’s make the best record we can make.'” Smith had the pipes, and the Lawrences had put a loving lick of paint on the garage-inflected pop of their youth, but it was Napes who brought the ingredients that made “Latch” the stand-out of Disclosure’s career so far: an unforgettable hook that pops and fizzes on the tongue, and lyrics that truthfully weave the first flush of infatuation in between the record’s cleanly rounded beats.

“Sam Smith was pulling pints, I was DJing at weddings, the Disclosure boys didn’t have a pot to piss in.”

There’s a negotiation process that comes with working on songs for other people, and Napes has become an expert in maneuvering it. While he coaxes the best out of his collaborators, he also doesn’t hold back when it comes to drawing on the resource that is his own lived experience. At the time of writing “Latch,” says Napes, “I was picturing chasing my girl round this club. Because at the time I was courting my girl, it was just one of those moments where I was trying to find her, and she was just trying to dodge me basically,” he laughs, and I gesture to the wedding ring he’s wearing. “Yeah, this is the girl I’m married to now! Most of the songs I’ve written actually are about her. “Rather Be” was all about her. She always hears that on the radio and it makes her smile at work.

After writing “Latch,” Napes went to work on writing and producing ballads with Smith while simultaneously writing upbeat hooks for Disclosure’s 2013 garage-pop debut Settle. Looking back, that balance was kind of necessary, as he remembers the intensity of the In The Lonely Hour recording sessions. “The one that stands out is ‘Stay With Me,'” he says, “because [Smith] really put himself on the line. He somehow just cut it in half and showed everyone exactly what he was feeling in that moment.” The drums on that song are played by Napes, who says they couldn’t get a professional to replicate his “sloppy bad timing,” and the choir on the chorus is all Smith. “We wrote and recorded it the same day, and when we were doing the backing vocals I was just being like ‘go in that corner and do it high,’ ‘go in this corner and do it low,’ getting him to run around. So one of the takes, I was like, ‘okay, now, back left, we need another falsetto,’ and he just didn’t reply. So I say ‘Sam? We need one more of those. Are you okay?’ And I went out and saw he was crying, because the song meant that much to him. In that moment it all just came flooding to him, it just struck a nerve. That was an amazing moment, because we’d got there.”

“I don’t know what it is, man,” Napes shrugs, “but people have said that they don’t know why they’re telling me all of this. Which is a compliment, obviously, I’m happy that I make people feel comfortable. I’m not a therapist or anything, but sometimes people open to me.” That intense, intimate style that Napes fostered with Smith led to an album of heartfelt piano songs that blew the US and UK away, and meant that the second ever record he produced was that of Mary J. Blige. “It really freaked me out for a bit,” he admits. “It’s quite a steep climb! The thing that I had to keep telling myself was, she’s come here to my studio because she likes what I do. She’s such a big icon, she’s someone my mum loves, she has all her albums—but that’s what I told myself, she likes what I do, so just do what I do and it’ll be fine. And it was.”

Pouring so much of himself into every session, it seems inevitable that Napes has stacked up a bunch of tunes that feel too personal to give away. That’s why he’s gearing up to release his Making of a Me EP, a handful of songs that began life in co-writing sessions, but took on a hefty personal resonance; so instead of giving them to an artist, he’s recorded his own vocals on them, and handed production duties to the likes of Disclosure and his musical idol-turned-friend, M. J. Cole.

Listening to two of the new tracks in his studio, it’s inescapable how neatly they fall between Napes’ two breakthrough projects: In The Lonely Hour and Settle. He sings in a crisp falsetto that occasionally bursts with a choral power, weaving stories of addiction and all-consuming love through spacious beats that are not quite as full-on as a Disclosure record, but unmistakably painted from their palette. The second track he plays me is an out-and-out love song, and lyrics like maybe I’m out of touch / when all I know is you tell me as plainly as the smile on his face that this is another one written for his wife. “Actually I sang it for her on our wedding day,” he says, admitting that this is the first and only time he has ever performed live as a vocalist. “It was like, if I’m gonna pick a moment to actually get up on the piano in front of people, there’s no better moment to do it. I thought if I do it in front of all my family then I’d be okay in front of anyone else.”

After having heard Napes’ upcoming debut single a grand total of twice, I catch myself singing it under my breath hours later; it’s obviously got the same magic ingredient as “Latch” and “Rather Be,” and so it’s laughable that on first playing it to me, he’s all coyness. He tells me that he’s not sure if he will ever perform live again: “I’ll see if anyone likes [the EP] and, if not, I’ll go back to the day job.” He’s being way too modest, and I’m certain he’ll be on stage by 2015, but even so, his day job is one which, sitting here in the cosy studio that’s played host to Blige, Rodgers and some of the UK’s freshest talent, doesn’t seem like such a bad prospect at all.