I was working as a network administrator in a gynaecological laboratory when the doctors came up to me and asked me if I could also develop websites. I said "yes of course!" and so I developed the first website for money.
It had an intro page, a typical bad habit for sites of that time, a self-drawn road map (Google Maps did not exist at that time) and actually every technique that you would be ashamed of today.
But this website marked the transition of my profession as a system administrator to web developer, from hobby to my current profession.