Infra

Investing in Stainless

Jennifer Li and Yoko Li Posted December 10, 2024

Modern software runs on APIs, yet developers still struggle with creating and maintaining high-quality APIs and software development kits. SDKs transform complex API calls into simple code that developers can use in their preferred programming language instead of writing raw API code. And most organizations lack the expertise and resources to build and maintain an ergonomic, polished developer experience to interact with their APIs. 

If your company relies on developer usage, this is bad for business. The quality of the SDK directly impacts the consumption and utilization of the APIs, as demonstrated by leading developer brands such as Stripe, GitHub, OpenAI, and Anthropic. However, those companies have invested heavily into dedicated API teams with the best developer-tooling talent — a luxury not many peers can afford. This is where Stainless emerges as a transformative force to help companies of any size produce type-safe, quality SDKs in minutes instead of months. 

The timing couldn’t be more perfect. As AI agents increasingly rely on APIs for function calling and automation, the quality of SDKs has become mission-critical. A poorly formed SDK can lead to failed API calls, type mismatches, and broken automation chains — issues that compound rapidly when AI systems are making thousands of API requests. As AI continues to reshape software development, well-designed SDKs aren’t just a nice-to-have, but a must-have.

The challenge is that designing good API specs and SDKs requires balancing the right tradeoffs and paying attention to details. Not only can the upfront investment be daunting, but the maintenance load of new language support, versioning, and changelogs continue to haunt the developers managing these products. Those are exactly the pain points Stainless solves, with a product embodying years of expertise producing the best developer-facing interfaces and offloading the majority of maintenance.

One may ask why Stainless-produced SDKs seem more handcrafted and loved by developers, given that SDK-generation is not new and many machine-generated SDKs are so obviously “machine code.” This is the magic sauce that truly sets Stainless apart: its unique approach to custom-code handling that allows developers to merge arbitrary changes that persist across future code-generation runs. 

This level of flexibility, combined with an obsessive focus on quality, has attracted an impressive roster of developer-brand companies, including OpenAI, Anthropic, Meta’s Llama Stack, Langchain, and Groq. These companies understand that in the AI era, the API interface is the product. It directly impacts both the human developer experience and how AI agents interact with their systems.

SDK generation is just the beginning, though. Stainless’s broader vision is to revolutionize API development by combining the best practices and standards, such as type safety and rpc style communication, all while maintaining simplicity and familiarity. They are in a position that could fundamentally reshape the foundation of how APIs are built and bring delightful experiences to every API producer and consumer.

Stainless exists because of a stellar team led by Alex Rattray, who previously architected Stripe’s client library code generation system. He’s a rare combination of technical craftsman and business builder. At Stripe, Alex witnessed firsthand how the traditional approach of manually crafting SDKs couldn’t scale with the growing demands of software development. This insight led him to found Stainless with a clear mission: make working with APIs effortless for developers. Since then, he’s assembled an exceptional team of developer-tooling talent, drawing some of the industry’s brightest minds to build the future of API development.We couldn’t be more excited to partner with Alex and the Stainless team as they execute on their vision of making world-class APIs accessible to every company. In a world where APIs are ubiquitous, Stainless is ensuring that the fundamental infrastructure connecting these systems is robust, efficient, and delightful to use by humans and AI agents. They’re hiring on all fronts, so please check out their career page and join them on this journey!

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