How to decide whether to build internal tools in-house or buy off-the-shelf solutions

When deciding whether to build internal tools in-house or buy off-the-shelf, many teams get misled by the idea that the "features are similar." Buying a SaaS looks fast, and building a small system in-house looks cheap, but the real trouble lies in who maintains it later, who handles data migration, how permissions are managed, and who updates it when processes change. I generally look at three…