Overnight success has been a long time coming for Sean O'Brien - aka troubadour of the hour, Sean OB. With major label backing and a fast-expanding fanbase, the pithy songwriter, whose music splices glimmering wit and punk fervour, is regarded as one of the most exciting Irish talents around. But behind a seemingly effortless rise lie years of heartache and toil.

"It was awful - I nearly gave up," the straight-talking Tallaght native tells Hot Press. "I had a good lost year were I didn't think it would ever work."

He never completely surrendered hope, though, and one of his demos eventually found its way to Dermot Lambert, once of '90s indie strivers Blink and now a guiding force behind independent gig promoters Garageband. Lambert in turn passed O'Brien's single 'Teacher' to esteemed BBC Radio 6 Music DJ Steve Lamacq, who was blown away, naming it his track of the week. Just like that everything changed.

"Dermot told me to get a band together because the songs were good," says O'Brien. "He would play my stuff in clubs and people would come up and ask what that was." Not long afterwards he was contacted by Rob Kirwan, the Dublin producer and engineer best known for working with Hozier, PJ Harvey and Depeche Mode. O'Brien had talked to other producers - but in Kirwan he saw someone who genuinely believed in him.

"He was pretty hot off doing Hozier when I sent him my demo. I thought, 'Well there's no way he's going to reply - but what's the worst that can happen?" Actually he got back straight away and he was mad into it. My confidence levels started to come back - I was like, 'Alright good ... yeah ... this is worth it."

What especially impressed O'Brien was that Kirwan wasn't seeking a quick payday. He regarded Sean OB as a talent to be nurtured rather than just another client. He took the younger man under his wing and helped bring his vision to fruition. From experience O'Brien will tell you such generosity shouldn't be taken for granted. "He said, 'Don't worry about money'. He just liked the songs. Sometimes you come across people and you think they're trying to make money off you. Rob wanted to work with me because he liked the tunes. It was like, 'Okay grand - don't look a gift horse in the mouth'."

Prior to his solo career, O'Brien had played with Dublin indie urchins The Raglans and, before that, fronted his own punk outfit. His solo material is more measured than his band work and the oft-bandied pronouncement that he sounds like 'Buddy Holly crossed with Jamie T' is a reasonable summation of what he's about. As a young man with a guitar it feels inevitable that he will be likened to Ed Sheeran, too, though his songs are far too bare-knuckle for the comparison to stick.

Life with The Raglans was an education. However, he was so busy he didn't have an opportunity focus on his own work. "When you're in a band you never have time away. After I left I took a year off and got into a rut. I wasn't working in music and lost all my contacts. In this business, if you're not touring, not meeting promoters, you can fall off the radar. There was a time I wondered what was I doing with my life. I'd wreck my friend's heads, asking them about their jobs. They'd tell me to go back to what I was good at - 'You're a musician, why are you asking these weird questions?'"

What was really the making of him, you suspect, were those early punk years. His solo material is unquestionably more commercial - that is, after all, why he's on a major. Yet there's an undertow of angst and menace that confirms he's no ordinary troubadour.

"Growing up, I wanted to be a cartoonist. Then aged 12 I started learning a guitar. We did loads of underage gigs and got banned from a lot of places. We played hardcore punk and everyone would mosh and go mental. Afterwards, the venue wouldn't have us back. So we'd have to go from venue to venue."

Sean OB's Half Cut EP is out on August 21.