Link’s Blog

Real-time messaging systems, networking internals, Go, and high-performance backends.

Jun 14, 2026
Incremental State Sync: How Clients Catch Up Without Re-Downloading the World

How real-time apps let a client catch up on state — conversations, group members, missed messages — after going offline, without re-downloading everything. A tour from replication logs and IMAP to Telegram, Discord, Matrix, and WeChat, and the distributed-systems theory underneath.

Distributed SystemsMessagingSynchronizationArchitecture
Jul 11, 2024
Group Chat vs. Live Stream Messaging: A Comparison

Two systems that look alike and are built oppositely: group chat optimizes for durable, reliable fan-out to mailboxes; live-stream messaging for lossy, immediate fan-out to millions of in-memory connections.

IMArchitectureLive StreamingMessagingDistributed Systems
Jul 6, 2024
Troubleshooting a UDP Packet Loss Issue on Linux

A multi-day hunt for UDP packet loss in a QUIC proxy: reading kernel receive-path counters in order, why a bigger socket buffer never helped, and what I'd reach for today.

LinuxUDPQUICNetworkingPerformance
Jul 4, 2024
High-Performance Go Service Architecture for Millions of Connections at Baidu

How a unified long-connection platform holds tens of millions of concurrent connections in Go: layered architecture, a connection state machine, and the goroutine, buffer, and GC discipline that keeps tail latency in budget.

GoArchitectureLong ConnectionHigh ConcurrencyNetworking