Ask HN: AI Modeling Projects with fast iteration times?

I have a good theoretical understanding of the math behind deep learning and have broad understanding of the recent architectures (Transformers, etc.). I'm looking to improve my practical intuition around this. What are some good resources and/or project ideas to get my hands dirty with training/fine-tuning models that will have a fast iteration time so I can get frequent feedback? I'm particularly interested in multi-modal models.