Observability Engineering, 2nd Edition

Chapter 29. Build Versus Buy (Versus Open Source)

The choice between building, buying, or adopting open source software (OSS) is rarely a simple technical comparison; it’s a high-stakes economic decision that determines where your organization’s most precious resource—engineering cycles—will be spent. While generating code has never been faster or easier in the era of AI, the long-term cost of maintaining bespoke infrastructure remains as high as ever. Every hour your team spends maintaining a nondifferentiating internal tool is an hour they are not spending on the core products that drive your market share.

This chapter provides a framework to help you navigate these trade-offs with clear eyes. We will examine the true costs—both obvious and hidden—of each approach and help you recognize whether your investments will compound into a competitive advantage or simply add to your technical debt. By the end of this discussion, you will be able to distinguish between the infrastructure that should be a commodity and what justifies custom development.

After all, build versus buy is not a binary choice; it’s a multidimensional spectrum. Pretty much everyone is going to end up buying some software, using some open source, and writing some code of their own. The important questions are: which, where, and why?

This topic is not new, but the trade-offs and relevance have shifted quite a bit in recent years. As mentioned in previous chapters, many companies now spend more on their observability ...