FeatureKeras (3.x)PyTorchTensorFlow
Primary GoalFast prototyping & ease of useResearch & flexible experimentationProduction-scale & enterprise deployment
Learning CurveLowest (easiest)Medium (Pythonic)Highest (more boilerplate)
EcosystemWorks with TF, PyTorch, & JAXMassive research communityStrongest production & mobile tools
Graph TypeDepends on backendDynamic (defined as you go)Static/Hybrid (optimized for speed)