Shift Left Is the Tip of the Iceberg

For those not aware, Shift Left[1] is (at this point) an old term that was coined for a specific use case, but now refers to a general concept. The concept is that, if you do needed things earlier in a product cycle, it will end up reducing your expense and time in the long run, even if it seems like it's taking longer for you to "get somewhere" earlier on. I think this[2] article is a good no-nonsense explainer for "Why Shift Left?".

[1] https://en.wikipedia.org/wiki/Shift-left_testing [2] https://www.dynatrace.com/news/blog/what-is-shift-left-and-w...

So “shift left” is roughly equivalent to “tests first” or “TDD”?

That's just one example of it.

Other examples:

* Replacing automated tests with (quicker) type checking and running it on a git commit hook instead of CI.

* Replacing slower tests with faster tests.

* Running tests before merging a PR instead of after.

* Replacing a suite of manual tests with automation tests.

etc.

Or, again more generally:

- implementing security features earlier (DevSecOps)

- implement tracing and metrics/analysis tools earlier, use them to test and debug apps earlier (as opposed to laptop-based solutions)

- building the reliable production model earlier (don't start with a toy model on your laptop if you're gonna end up with an RDS instance in AWS; build the big production thing first, and use it early on)

- add synthetic end-to-end tests early on

The linked article is talking about Shift Left in the context of developing semiconductors, so you can see how it can be applied to anything. Just do the needed thing earlier, in order to iterate faster, improve quality, reduce cost, ship faster.