Tooling is a Scaling Strategy

In a rapidly scaling technological environment, the challenge of managing complex systems often outpaces human cognitive capabilities, necessitating improved tooling and architectural strategies. Companies like Mercado Libre and Nubank exemplify two distinct approaches to handling these challenges: Mercado Libre implemented a governance-focused approach with SDK wrappers and centralized control planes to manage and enforce rules across their extensive caching infrastructure, while Nubank adopted a fundamentally different data model with Datomic to eliminate the instability inherent in mutable systems, thus reducing the need for defensive tooling. Both strategies aim to address the inherent constraint of human cognitive limits in understanding and controlling large-scale systems, with Mercado Libre focusing on enforcement and control, and Nubank reducing complexity by stabilizing the data model. This shared understanding underscores the engineering community's move towards evolving infrastructure around human limitations, as seen with the development of Valkey, which addresses structural failures at the project level and reflects wider industry trends discussed at conferences like Unlocked.