Editor's Note: The development of the crypto industry has never been isolated; it often echoes past technological waves. This article delves into the "splitting and reintegration" cycle of SaaS and fintech, analyzing deeply how this logic is reproduced in DeFi and crypto applications. The author not only sets the stage with Web2 examples like Airbnb and Robinhood but also combines the evolution of Uniswap and Aave, revealing how crypto protocols have transitioned from single-point primitives to modular "financial Legos," and further into today's gradual integration into super apps. For readers trying to understand the future landscape of DeFi, this is a framework to observe the future through history.

As the crypto industry matures, investors are starting to look for clues from past technological waves to predict the next significant trend or inflection point. Historically, digital assets have struggled to directly compare with previous tech cycles, making it challenging for users, developers, and investors to anticipate its long-term development path.

This situation is changing. According to our research, the crypto "application layer" is evolving, with its pattern closely resembling the "splitting and recombination" cycle experienced by SaaS (Software as a Service) and fintech platforms.

In this article, I will explain how the splitting and recombination cycle in the SaaS and fintech fields is being replicated in DeFi and crypto applications. The evolutionary logic of this pattern is as follows:

To understand the splitting and recombination cycle, the concept of "composability" is crucial. In the fintech and crypto communities, "composability" is a common analytical term, referring to the ability of financial or decentralized applications and services—especially at the application layer—to seamlessly interact, integrate, and further build on each other like Lego bricks. Based on this core concept, we will further analyze the evolution path of product structures in the following two subsections.

From Vertical to Modular: The Great Split

In 2010, Andrew Parker of Spark Capital published a blog post depicting how dozens of startups were leveraging Craigslist's "splitting" opportunity. At the time, Craigslist was a "horizontal" internet marketplace offering various services from rentals, part-time jobs to second-hand item transactions, as shown in the diagram below.

Parker's conclusion is that many successful companies—Airbnb, Uber, GitHub, Lyft—have carved out an extremely narrow vertical from Craigslist's broad functionality and significantly improved upon it. This trend kicked off the first wave of "market unbundling": Craigslist, a large and general-purpose platform, is gradually being replaced by applications focused on a single purpose. These newcomers have not only enhanced Craigslist's user experience (UX) but have completely redefined the experience. In other words, "unbundling" breaks down a broad platform into narrower, independently functioning verticals that meet user needs in a unique way, thus disrupting Craigslist.