Growing old is mandatory; growing up is optional.
Attributed to Chili Davis
When it comes to API management, understanding the impact of changes is vital. As we discussed in the previous chapter, there are different types of costs associated with changes to your API: work costs, opportunity costs, and coupling costs. The overall cost of change depends upon the part of the API you are changing.
What’s more, the costs of change for an API aren’t static—as the context of the API changes so do the costs associated with changing it. For example, the coupling cost of an unused API is near zero, but, the coupling cost for the same API with hundreds of consumer applications depending on it would be massive by comparison.
In truth, the reality of API change management is even more complex than that example suggests. What if your API only has a single consumer that happens to be owned by a major partner of your business? What if you have hundreds of registered developers, but none of them are driving revenue to your core products? What if you are managing an API that is profitable but doesn’t fit your business model anymore? In each of these cases the cost of change is completely different. In fact, there are probably thousands of contextual permutations to consider. All this variation makes it difficult to create a blanket assessment of API maturity for all API products.
Although it’s a challenging prospect, it would still be nice to have a universally ...