Chinese artificial intelligence start-up DeepSeek has updated the user interface of its flagship chatbot by adding an advanced “thinking” feature, as its app recorded a massive 90 per cent jump in monthly active users (MAU) in December. The upgrades, including a deep research mode similar to OpenAI’s namesake product, marked a rare improvement on the consumer side for the Hangzhou-based firm at a time when anticipation was building over its next-generation models, analysts said. DeepSeek’s...