When to ensure testability for your product?
While designing the architecture..
While mkst of us know this, very few actually see it through.
We build a piece of software and then decide how to test it,
Instead while designing it make sure you have ‘test probes’ in there.
When I worked for safety critical applications, we left test points on the PCB to check the circuit
Those points were not used for any feature of the product, but were there just to help test it.
So, testers get involved when the architecture is being designed,
Or the architects trained to ensure the system is testable themselves.