Keras 3 backend selection before import: tf.keras aliasing and legacy API support
Goal Determine how Keras 3 enforces backend selection prior to the first import and how the tf.keras aliasing layer preserves or drops legacy Keras 2 symbols when different backends are chosen. Constraints Backend must be chosen via KERAS_BACKEND or keras.config.set_backend() before any import keras . Switching backends later in the same process is unsupport
keras