Most of the time when we make mistakes in our code, a message gets displayed wrong or an invoice doesn’t get sent. But sometimes when people make mistakes in code, things literally explode, or bankrupt companies, or make web development a living hell for millions of programmers for years to come.

Join Mark on a tour through some of the worst mistakes in the history of programming. Learn what went wrong, why it went wrong, how much it cost, and how things are really funny when they’re not happening to you.

You’ve seen the tweets about vibe-coded apps getting hacked over silly mistakes — but what can we actually do about it? AI coding agents are amplifiers: they ship faster, but they also ship insecure code, and asking them to “make it secure” rarely works.

Security This talk shows a better approach: shift the focus from chasing specific attacks to teaching solid defensive coding principles. We’ll build security knowledge directly into the agent — using skills, hooks, and standards — so it looks up the right guidance, plans for it, and reviews its own work. You’ll leave knowing how to make your agent produce secure code far more often, by default.

Scaling a database sounds like a great idea, but have you considered the number of ways it can fail? Add some nodes, throw in replication, and suddenly you’re explaining to stakeholders why two customers saw two different truths at the same time. Turns out distributed systems have opinions about physics - but data modeling can help.

This session covers the fundamentals (replication, consistency, partitions) and the tradeoffs nobody mentioned when they said “just scale horizontally.” We’ll look at real failure modes and practical patterns for building systems that handle chaos without dragging your app down with them.