Should I use stateless or stateful?

Hello there, I'm wondering about a question that's been bugging me lately. In the realm of blockchain development, should I opt for a stateless or stateful approach? I understand that stateless systems rely heavily on external databases for maintaining state, while stateful systems manage their own state. But I'm unsure of the implications of each approach in terms of scalability, performance, and overall design complexity. Could you elaborate on the pros and cons of each, and maybe even offer some guidance on which might be more suitable for a particular use case? Thank you in advance for your insights.