worst mistake was probably introducing an infinite loop in the category tree for e-commerce site...

in the vein of true agile and considering MVPs and what not we had not yet automated everything. the client would send category updates as a spreadsheet and i had a script to generate the sql and jam it into the site. having run the script several times in the past I thought I'd just throw the update into production and call it a weekend...

it wasn't long before I started fielding calls that the site was unstable. no page would load and the server kept crashing under trivial load. well an entire frantic weekend later I discovered the category load hit an edge case I hadn't considered and I had introduced an infinite loop in the navigation of the site.

i'd like to say I learned my lesson and never just threw changes into production again, but what can I say - I like living on the edge. I did however learn that loop detection can be a valuable thibg