I am the first to ask for quick feedback loops, which makes the dev environment so much enjoyable. But I have also seen some detrimental long term effect of this.
I have seen developpers "coding to the test". By that I mean they are modifying a piece of code they do not know well, and assume that if test pass, that must be good. Without understanding that test will never cover all possible inputs/states of the system.
This "coding to the test" can appear very fast with a quick feedback loop, making possible to "monkey code" something until it passes.
If you do not have careful review, by people knowing the system, this will end badly, with race conditions only appearing in production, integration failing randomly.
I have seen developpers "coding to the test". By that I mean they are modifying a piece of code they do not know well, and assume that if test pass, that must be good. Without understanding that test will never cover all possible inputs/states of the system. This "coding to the test" can appear very fast with a quick feedback loop, making possible to "monkey code" something until it passes. If you do not have careful review, by people knowing the system, this will end badly, with race conditions only appearing in production, integration failing randomly.