A developer updated a library, breaking dependent applications.
Users complained loudly.
The senior developer asked, “If the change improves the library, what does it break besides the code?”
And then, “When something breaks, what was it depending on that you didn’t see?”
Sitting with the Koan
When we speak of breaking changes, we typically frame the conversation in technical terms: semantic versioning, deprecation warnings, migration guides. But this koan invites us to look beyond the immediate disruption to examine what truly fractures when we break compatibility.
The senior developer’s first question – “what does it break besides the code?” – points to a web of expectations and relationships we rarely make explicit. It breaks the trust that tomorrow will look like today. It breaks the assumption that improvement and stability can coexist without tension. It breaks the comfortable fiction that our systems are as modular and independent as we claim them to be. When users complain loudly, they’re not simply upset about compilation errors or runtime failures. They’re experiencing the violation of an implicit social contract: that the ground beneath their feet will remain solid.
The second question probes even deeper: “When something breaks, what was it depending on that you didn’t see?” This is where the koan becomes truly challenging. Every breaking change is an x-ray of our system’s hidden skeleton. It reveals the undocumented behaviors we relied upon, the implementation details that leaked through our abstractions, the edge cases that became load-bearing walls. We discover that we weren’t just depending on the library’s advertised interface – we were depending on its timing, its error messages, its memory patterns, perhaps even its bugs.
For those maintaining hosting environments and infrastructure, this dependency blindness carries particular weight. A PHP version update that should be routine suddenly reveals that a critical application was relying on a deprecated function. A security patch to a web server exposes that someone wrote code dependent on specific header ordering. An operating system upgrade breaks software that made assumptions about filesystem behavior that were never in the documentation. Each breaking change becomes a teacher, showing us the difference between the systems we think we built and the systems that actually exist.
The koan doesn’t offer the comfort of a solution. It doesn’t tell us to never make breaking changes or to maintain perfect backward compatibility forever. Instead, it asks us to sit with the uncomfortable truth that every system is built on a foundation of invisible assumptions, and every improvement risks discovering which assumptions were false. The question isn’t whether to break things, but whether we’re willing to see clearly what we’re actually breaking – and what that reveals about how we build, maintain, and understand the systems we create.
What dependencies in your own systems exist only in shadow, waiting for the light of a breaking change to reveal them?