Popular Atlanta-based engineer Seth Firkins has passed away, XXL has learned.

Firkins was a mainstay on the ATL rap scene, serving as Future's personal engineer and working closely with acts like Young Thug, Young Scooter, Zoey Dollaz and others. Artists are taking to social media to express their condolences for Firkins.

Mike WiLL Made-It posted a photo in memory of the beloved engineer captioning the pic, "Naw Fr, and you can never be replaced big dog, 1 of a kind fr, REST EASY OG, LOVE! RIP @sethfirkins."

Zoey Dollaz, who worked with Firkins as a part of Future's Freebandz outfit, is taking the loss hard. "I met u through Pluto a year or two ago dealing with music but literally u became an actual friend outside of music," he captioned a video of Firkins on Instagram. "Always checking on me always telling me u grew to love me like a Lil bro and how talented I am smh if this hurt me I can imagine how Hndrxx feeling rest in heaven big guy @sethfirkins grateful I got to meet u."

XXL interviewed Firkins, a Kentucky native, for our Spring 2017 issue. He talked about the epic grind he and Future had when they worked together. "We just spent a week and a half at Tree Sound [Studios]. When I tell you we still have a couple hundred songs that are hard, that's no hyperbole," he said. "There are so many songs that have to come out before I die."

Future posted a pic from the studio with Firkins and wrote a heartfelt message dedicated to his longtime engineer. "I got a call saying u died in your sleep?" writes Future. "First thing came to my mind is, why are you sleep at 5am? That's when we record our best shit & I tell u "don't" fall asleep we got more work to do."

See what other artists, including TM88, Sonny Digital and more, are saying on social media about Firkins' passing below. You can watch also watch an in-depth interview with Firkins on a recent episode of Pensado's Place.

XXL has reached out to Firkins' team for comment.