Lessons learned when scaling from one to many AWS regions

As user bases expand globally and data residency requirements increase, engineering teams often encounter the complex challenge of scaling applications beyond a single AWS region, this is a shared experience for many successful start-ups. In this talk, we’ll cover the real-world journey of how the cloud engineering team at Slido worked on evolving and scaling our setup from a single-region deployment to a resilient, multi-region AWS architecture spanning multiple locations in Europe, North America, and Asia.

We’ll break down key technical decisions and their real-world impact on engineering teams, including:

• Designing scalable Infrastructure as Code (IaC) using modular, DRY principles

• Tackling the challenges of naming conventions, tagging, and globally unique resources across regions

• Operational lessons in monitoring, observability, and minimising blast radius through regional isolation

• Strategies for elasticity, failover, and right-sizing across services such as RDS, Lambda, CloudFront and more

• Reflections from production incidents that informed decisions around account structuring, permissions, and deployment automation

This session focuses on practical implementation, offering insights into what worked well, what didn’t, and how technical expectations can sometimes differ from operational reality. Whether you’re preparing for, or already navigating, multi-region AWS workloads, this talk will provide tangible strategies, architectural patterns, and hard-earned lessons to support your journey.