Sergi Delgado joins us to discuss Watchtowers, his prior work in Bitcoin and Lightning privacy, Python vs. Rust and the impact of Eltoo. We cover: - Sergi’s prior research - Mapping Network Topology Research (02:46)   - TxProbe paper  - Andrew Miller  - Coinscope  - Episode on Address Relay with Martin (04:28)  - Block-only connections PR by Suhas (07:32) - An Empirical Analysis of Privacy in the Lightning Network (09:18)   - Lightning white paper, 2016 (09:48)   - Security and Privacy of Lightning Network Payments with Uncertain Channel Balances (13:38)   - Episode with Sergei on Probing   - Channel Jamming paper (13:50)   - Episode with Clara and Sergei - Should we pay for failed payments? (14:19)   - HTLC withholding vs. HTLC hodling (15:48)   - Is Lightning flawed when it comes to privacy? (16:32) - Watchtowers (17:44)   - Python PoC (21:49)   - ZmnSCPxj’s writing watchtowers   - Building on LDK (24:20)   - Transition to rust (24:45) - Altruistic towers vs professional services (30:21) - More privacy considerations in Lightning (34:11) - Monitoring and reacting paradigm (44:04) - Storage and Eltoo (50:06) - Professional tower revenue models - subscription vs. bounties (53:00)