Don't DIY your event store

Event-driven architecture is how enterprises get auditability, real-time responsiveness, and AI-ready data out of their core systems. When the initiative is approved, a familiar proposal follows: our engineers can build the event store themselves on general-purpose tools. The proposal usually prices the prototype. It rarely prices the product. An event store is not a database table with an insert-only rule; it is a distributed system that must replicate, order, and serve events reliably, with its own recovery, evolution, scaling, and operational demands. Teams that build one take on that scope permanently, funded from the budget that was meant to deliver business outcomes. The comparison below lays out the full commitment, so the decision is made on total cost of ownership