Instant payment frameworks are transforming global finance, but few institutions have faced the infrastructure scale required by Brazil's Pix network. At over 130 million customers, managing this transactional volume demands an architecture that cannot afford traditional banking maintenance windows, consistency trade-offs, or runaway cloud costs.

In this session, Cat Swetel breaks down Nubank's runtime environments, database topologies, and zero-downtime designs required to support massive financial scale. We will dive deep into the specific socio-technical and systems engineering trade-offs made to keep pace with explosive growth, handle unpredictable traffic spikes without over-provisioning, and ensure sub-second global availability under rigid regulatory constraints.