We all love exciting tech—microservices, event sourcing, Kubernetes. But when do we actually need them? Too often, we build for scale before we even have users, piling on complexity that slows us down, makes onboarding harder, and creates a tech debt spiral that’s hard to escape. This talk explores how overengineering creeps in, why simplicity is your best scaling strategy, and how Elixir’s lightweight approach makes it easy to evolve systems sustainably. Through real-world lessons (including my own missteps), we’ll challenge the instinct to overcomplicate and rethink what "just enough" really means—not just for today, but for a future that’s sustainable, maintainable and scalable for the long haul.