Sierra raises $950M at a $15B+ valuation with 40% of the Fortune 50

When you're scoping a customer-service or sales-development AI vendor in the next quarter, add this question to your evaluation rubric: how is the agent's reasoning trace surfaced to the QA team running spot-checks? If the answer is a logging dashboard, that's a demo; if it's an annotation tool integrated with your case management, that's a product. The pause before someone answers is the data point — and the same question separates the Sierras of the next 12 months from the demos.