I built a phenotype generator for crested gecko genetics. Here's how I modeled a hobby that can't agree on its own rules.

Crested gecko morphs are one of the most commercially significant trait systems in the reptile hobby. Serious breeders run pairings worth thousands of dollars based on genetic predictions. And the community still actively debates how many of those traits actually work. Breeders are manually constructing phenotype strings, getting them wrong, listing animals inaccurately, and making pairing decisions on bad information. Not because they're careless. Because the species is young, the documentation is inconsistent, and for some traits, scientific consensus simply doesn't exist yet. I'm an active crested gecko breeder. I also built Geckistry, a full breeding management platform that runs my own operation. When I got to the genetics features, I had to solve a problem most developers never encounter: how do you build a rule engine when the domain experts disagree on the rules? Here's what I built and how it works. Code reference for this article: github.com/Dusttoo/reptile-genetics-engine Wh