In Episode 13, we sit down again with Matt Corallo and discuss his work on the Lightning Development Kit (LDK). In this conversation we cover: - Starting Rust-Lightning (1:20) - Language bindings challenges (4:09)  - FFI (5:32) - Interoperability of Lightning (7:10) - Zero-value invoices (7:35) - Keysend/push payments/spontaneous payments (8:20) - What is the LDK stack? (9:29) - Anchor Outputs (10:41)  - Child pays for parent (CPFP) (11:02) - Who tracks the onchain state when using LND? (12:30) - LDK tracks the channel commitment transaction, how is that done? (13:45)  - Compact block filters - Contrasting multiple implementations working from a spec in Lighting vs. no spec with one dominant reference implementation in Bitcoin (14:58)  - The Lightning Spec - What's the state of the Lightning Network? Have we moved beyond #reckless? (18:49)  - Denial of Service (DoS) vulnerabilities    - Channel Jamming (22:00) - Eltoo and the punishment dynamic (22:45) - Will the network trend to trusted relationships and lend itself to KYC? (24:50) - FATF updates its guidance on Virtual Asset Service Provider (VASP) (26:50) - Where LDK goes from here? (29:55) Thanks to Caralie for the sound engineering.