From the Super Mario Wiki
Andrew Iverson, occasionally credited as Andy Iverson, is a former employee of The Software Toolworks. He was one of the writers for the MS-DOS and PC versions of Mario's Time Machine, and the sole "scriptwriter" for the SNES version. He was also one of the software designers for the SNES version of Mario is Missing! and, along with Henrik Markarian, also served as the director of Mario's Early Years! Fun with Letters and Mario's Early Years! Fun with Numbers. He went on to co-found Starsphere Interactive with Markarian (whose last game was released in 2004 with Star Trek: Shattered Universe before it seemingly went defunct). In Mario's Time Machine, Iverson appears as a physical character within the game, and meets Mario after the latter travels to Novato in 1994.
Mario's Time Machine
According to Mario's Time Machine, Andrew Iverson was working out of The Software Toolworks' headquarters when Bowser steals the Floppy Disk holding the final version of Mario's Time Machine and Mario travels to the headquarters to return it. When first meeting each other, Mario introduces himself, and Iverson likewise introduces himself as a writer and a programmer while marveling at the fact that Mario himself is visiting him. He then mentions the game he is working on, and Mario asks what role writing plays in a game. Iverson explains that they spend hours writing out the scenario and the dialogue so that Mario is able to speak. He then gives him a Script for Mario's Time Machine that was "rewritten only 50 times". Mario asks if he is able to write Bowser out of the script, leading Iverson to ask if Bowser is creating trouble again. He is concerned that Bowser may be in the area, and wants to call the game's editor, Rachel Koretsky, before he steals one of their scripts. Mario glumly tells him that he has stolen their Floppy Disk, and Iverson guesses that Bowser is planning on preventing the game from ever being created, therefore allowing him to travel across time without any consequences. Iverson is reassured when he is told that Mario has the disk in his possession, but he then tells him that he needs to make one final rewrite to the game's script. However, he cannot complete it without a Bug Report from the QA team. Mario soon gives him the report, and Iverson excitedly says that he can now write Mario's final joke into the script, and he begins loading up the artwork that he needs. Sone music (which the player cannot hear) then starts playing, and Mario asks about it. Iverson explains that it was composed by Rob Wallace (more specifically, he composed the game's "Mario Music"), and he tells Mario to bring the Floppy Disk to David Grenewetzki before the writers decide to change the script again.