Mehmet Demiray

I started coding before my formal education, which took a detour into Metallurgical and Materials Engineering. During that time, I specialized in EN and ASME standards, where the work is built around precise calculations: phase diagrams, tolerance stacks, conversions, and fatigue limits. Numbers carry consequences when a part has to survive on a real production line, so the discipline taught me to be careful at the boundaries.

After working in that field for a while, I returned to software development. With over 15 years of professional experience, I see that the two fields have more in common than people assume. Both reward people who care about correctness, edge cases, and the quiet places where assumptions break.

Callculation grew out of that habit. The calculation tools I needed online were often slow or wrong in subtle ways. I started building the versions I wanted to use, then opened them up so other people could reach for the same.

Alongside the work on tools, I do security research. I report vulnerabilities through HackerOne and Bugcrowd, and I have an acknowledgment from Microsoft's Security Response Center for a 2021 disclosure. Reading the way other engineers fail is a good way to remember how easy it is to ship broken assumptions, and it keeps me honest about input validation in the calculators here.

If you spot a bug, want a tool that does not exist yet, or just want to talk about how a calculation should behave, drop me a line. I read every message.