Building a chat SDK that works seamlessly across apps sounds simple until you realize it needs to handle offline users, background processes, push notifications, and rate limiting, all while staying lightweight. The difference between a chat system that delights users and one that frustrates them often comes down to how elegantly it handles the messy reality of mobile connectivity. This is why designing an in-app chat SDK requires careful consideration of real-world constraints that many developers overlook. Architecture Overview An embeddable chat SDK sits at the intersection of three critical concerns: the client-side integration, backend messaging infrastructure, and platform-specific handling. The SDK itself is typically a lightweight wrapper that manages local state, handles UI components, and communicates with a centralized messaging service.…