papers/hanzo-api-gateway/sections/01-introduction.tex

\section{Introduction}


Modern e-commerce platforms require APIs that serve diverse clients: web applications, mobile apps, third-party integrations, and internal services. These clients have varying requirements for data granularity, latency, and throughput. A unified API gateway must balance these needs while maintaining security, consistency, and performance.

Hanzo API Gateway addresses these challenges through:

\begin{enumerate}
    \item \textbf{Dual Protocol Support}: REST for simplicity, GraphQL for flexibility
    \item \textbf{Intelligent Rate Limiting}: Per-client, per-endpoint quotas with burst handling
    \item \textbf{Multi-Layer Caching}: Edge, gateway, and origin caching with coherent invalidation
    \item \textbf{Unified Authentication}: API keys, OAuth 2.0, and JWT with fine-grained permissions
\end{enumerate}

\subsection{Contributions}

This paper contributes:

\begin{itemize}
    \item A formal model for unified REST/GraphQL API design
    \item A distributed token bucket rate limiter with sub-millisecond overhead
    \item A cache coherence protocol for e-commerce data with strong consistency guarantees
    \item Production validation at 180K requests/second with 99.99\% availability
\end{itemize}