Why 'shift-left' lost to 'shift-to-runtime'

For years the mantra was shift-left: catch issues earlier in the pipeline. It still helps — but the center of gravity is moving to runtime, where agents observe real behavior and remediate before a human is paged.

The reason is simple: most of what breaks in production was never reproducible in a test. Watching the live system beats predicting it.

Signal: observability vendors that ship action, not just alerts, are the ones repricing the category.