API-first companies have transformed the software industry by creating specialized, standalone functionalities that can be integrated into larger platforms, forming what is now known as the API economy. Initially, the concept of monetizing APIs faced skepticism due to challenges in marketing and adoption, particularly among non-technical decision-makers. However, pioneers like Twilio demonstrated the viability of APIs as products, significantly reducing the complexity of integrating telephony services and inspiring other companies such as Stripe and Algolia to offer their own specialized services. IFTTT and Zapier further popularized API usage by enabling non-developers to automate tasks across software applications, broadening the appeal of APIs beyond technical audiences. As APIs became mainstream, they allowed tech startups to focus on their core offerings while outsourcing other functionalities, leading to the rise of niche API providers like Tradier and Clearbit. This shift has resulted in a robust ecosystem where APIs are integral to software development, optimizing the software stack for enhanced speed, performance, and usability, and paving the way for continued innovation.