An Alternative To JSON Responses: Argo in WhatsApp

Session description

Optimizing wire size is in WhatsApp's DNA. In the early days, we transformed verbose XML into a compact binary protocol (WAP) that helped us serve users worldwide on constrained networks. Now, as we migrate to GraphQL, we faced a new challenge: JSON responses were 30% larger than WAP-encoded equivalents. This talk tells the story of how we solved that problem—by leveraging GraphQL's type system to outperform not just JSON, but WAP and protobufs too. We'll share the technical approach (implementing Argo), the results (27-50% smaller responses), and why this represents the next evolution in efficient data transfer for Meta's apps.