Alexander Matsnev

On the reliability of long-lived TCP connections

September 12, 2026 · 8 min read

TCP connections that stay open for hours behave very differently from short-lived ones. In this post I look at what breaks first: window scaling, middlebox state, or application-level timeouts.

Notes on running a personal mail server in 2026

August 28, 2026 · 12 min read

Deliverability, DKIM rotation, and the small operational details that matter after the first year.

A short comparison of QUIC stacks

August 5, 2026 · 6 min read

quiche, ngtcp2, msquic, and the Go implementation. Different trade-offs in different environments.

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