I started editing in July 2012 on the English Wikipedia, although I also primarily contribute to Commons, Wikidata and OpenStreetMap, and occasionally edit several other WMF projects. My user rights include extended-confirmed and template editor on the English Wikipedia, and autopatrolled and file mover on Wikimedia Commons. I am also an inactive administrator on RationalWiki (the user right is generally handed out like candy there; I don't know what they were thinking).
I have accumulated more than 250,000 edits across Wikimedia projects and uploaded over a thousand changesets on OpenStreetMap, although many of these contributions are thanks to semi-automated tools like pywikibot, QuickStatements and AWB.
Some of the templates and modules I've contributed to. I haven't listed helper templates, mainly because there would be more than 300 of them. I've also omitted navboxes and route diagrams.
I've uploaded more than 50,000 images to Commons, though most of them are cookie-cutter BSicons. I've also renamed several thousand files, mostly for improving their titles' logic and consistency.
I've also worked on some other things on Commons, although they're basically all SVGs. A majority of these are based on other people's work or were originally uploaded by others.
Other things
I run the archive-things tool on Tool Labs. Despite being hosted on WMF infrastructure, it doesn't make any edits; it just repeatedly archives things to the Wayback Machine (hence the name).