Graded C on resilience. In Vannus's assessment it depends on a single upstream model with no disclosed alternative — acceptable, with limits worth knowing.
Calendly currently uses large language models (LLMs) from OpenAI and may add other vetted providers over time.
Vannus grades Calendly against nine dimensions of trust — data sovereignty, training privacy, compliance posture, operational resilience, exit portability, and more. The heaviest criterion asks whether the tool builds its own AI or resells someone else's model; where the vendor discloses it, the grade cites the vendor's own documentation. No paid placements — scoring is walled off from affiliate revenue. See the methodology →