Doesn't have to be Siri, could be a new experience. Chat or voice input is acceptable. This question specifically targets the architecture of the product; something that is not considered a large language model would not qualify.
Definition from Wikipedia:
A large language model (LLM) is a type of language model notable for its ability to achieve general-purpose language understanding and generation. LLMs acquire these abilities by using massive amounts of data to learn billions of parameters during training and consuming large computational resources during their training and operation.[1] LLMs are artificial neural networks (mainly transformers[2]) and are (pre-)trained using self-supervised learning and semi-supervised learning.
Note: the parameter size does not matter as much as the training data. It should be trained in a largely similar way to existing products to be considered an LLM, even if it somehow doesn't have billions of parameters.