Michael Bumann, co-founder of Alby, discusses the project's journey from a browser extension to a self-custodial Lightning wallet, Alby Hub. He highlights the integration of Nostr to enhance digital identity and user sovereignty. The conversation covers security considerations for browser extensions, innovative features like 'zapping', and the potential of a mobile app for seamless payments. Bumann also emphasizes merchant adoption and the challenges of Lightning payments, alongside the future prospects of self-custodial solutions in the cryptocurrency landscape.