Reynolds has writing credits on four episodes of Jessica Jones, including the Season 1 finale, "AKA Smile." Reynolds also wrote for the Fox series The Following.
Iron Fist will be the fourth series in Marvel's line of street level Netflix heroes, and will join with Daredevil, Jessica Jones, and Luke Cage in the crossover series The Defenders.
Marvel and Netflix have yet to cast their Iron Fist. The series is expected to debut in 2017, though Netflix hasn't yet made that official.
Reynolds also served as a co-Executive Producer on Jessica Jones, we've reached out to Marvel to clarify his role on Iron Fist and will let you know as soon as we hear back.