I am looking for an experienced ARM Thumb assembly programmer with a strong background in Game Boy Advance ROM hacking, specifically Pokémon FireRed. This project is not based on vanilla FireRed. I am working with the Hubol version, which is an outdated Complete FireRed Upgrade (CFRU)-based build. In this version, the experience gain system has already been heavily modified and differs significantly from the original FireRed implementation. Because of this, the task is not a simple port, but rather an adaptation/rework of an existing custom EXP system. Project Goal The goal is to implement a Generation 6+ style experience gain system with the following behavior: When the player does NOT possess the Exp. Share item, the experience system should follow the current (Hubol/CFRU-based) behavior. When the player DOES possess the Exp. Share item, the system should switch to a Gen 6+ style EXP distribution: All Pokémon in the party receive experience after battle. Participating Pokémon receive a larger share of the experience. Non-participating Pokémon receive a reduced share, consistent with modern mechanics. Technical Context The ROM is based on a CFRU-style structure, but modified (Hubol version). The EXP system is already altered, so existing routines may need to be analyzed and partially rewritten. I can provide the CFRU offset.ini file, which should contain the relevant hooks, function locations, and important addresses to help navigate the codebase. Requirements I am looking for someone who: Has strong experience with ARM Thumb assembly (GBA) Is familiar with FireRed and CFRU internals Is comfortable working with non-standard / modified codebases Can analyze and adapt existing EXP routines rather than relying on vanilla assumptions Writes clean, stable, and well-documented code The final implementation should integrate smoothly into the existing system, avoid breaking other mechanics, and replicate Gen 6+ EXP behavior as accurately as possible, with activation strictly tied to possession of the Exp. Share item. If you have prior experience working with CFRU, custom battle systems, or EXP rewrites in Pokémon ROM hacks, I would be very interested in collaborating.