What is your source of truth

This topic is probably going to cover a few days this week. I refer to it as the "source of truth" for data in a system. I have often worked on systems where data can arrive in to the system from a variety of sources, typically its from third-party APIs and various user inputs.

A question then typically arises of what to do when data from these various sources conflicts with each other. This is especially the case if there is some automated updates that means we need to cater for understanding which source of data should take priority. Is it the API or the current state of the database? Generally this requires a conscious decision to be made in the business or organisation for work to move forward, otherwise as a developer you are going to be stuck with bug reports or similar until it is resolved.

Essentially get clear on where your source of truth is for each item of data in your system, especially when you can get it from multiple locations. Tomorrow I will talk through an example of addressing this.