How did I improve the authentication process for millions of users by hundreds of percent? I will talk about our architectural change implementation details, and will teach how we leveraged practical design patterns using Redis, AWS Cloudfront, microservices and observability tools to get top-level loading time performance of our passwordless-based authentication solution. During this talk, I will describe a change that had a significant impact on how customers perceive us as their authentication mechanism. Serving major enterprise companies and well-known brands, we must strive for cutting-edge performance. I will discuss practical architectural changes, design patterns, and various cutting-edge technologies, such as Passkeys, WebAuthn and FIDO2. The true value of this talk lies in integrating all these components, allowing you to explore how familiar tools can be combined with theoretical design patterns to create a remarkable architecture.