How One Rust Core Can Power Many SDKs

A new architectural pattern uses a shared Rust core to build and maintain software development kits for multiple languages more efficiently.

A presentation from Temporal’s Spencer Judge detailed how to use Rust to build a single, shared core for software development kits (SDKs) that work across many programming languages. This pattern involves writing the main logic once in Rust, then creating thin wrappers for platforms like Python, Go, or Java. This avoids writing and maintaining the same complex logic in multiple codebases. Judge explained the technical hurdles, such as making different languages communicate effectively using a Foreign Function Interface (FFI). He also covered challenges like bridging asynchronous systems and managing memory safely at the boundary between the Rust core and the language-specific layers, based on Temporal's real-world experience.

This pattern is valuable for any company providing developer tools for multiple languages. Maintaining separate SDKs is expensive, slow, and can lead to bugs and inconsistencies. By centralizing core logic in Rust, known for performance and safety, companies can speed up development, lower maintenance costs, and guarantee all SDKs behave identically. This strategy lets engineering teams focus on a single, robust implementation of key features. For CTOs and engineering leaders, it offers an efficient way to scale their developer ecosystem. Developers benefit from more reliable and consistent tools, regardless of their preferred language.

The talk also acknowledged the limitations of current methods, especially FFI's complexity. Judge suggested emerging technologies like WebAssembly (Wasm) could offer a simpler, more secure alternative for cross-language communication. As more companies adopt this Rust-centric model, the surrounding tools and best practices are expected to mature, making the pattern more accessible. This trend highlights a broader industry shift toward using high-performance, safe languages like Rust for foundational software components, even in projects that primarily use other languages.

This pattern allows companies to support developers on many platforms with less effort, ensuring consistent and reliable tools. It centralizes complex logic, making maintenance easier and development faster.

Adopting a Rust core for SDKs can significantly reduce engineering costs and time-to-market for new developer tools. It improves product quality and consistency, which can increase adoption and customer satisfaction.