Xenthoris
Long-form technical notes, written by operators for operators.
Understanding TLS 1.3 Session Resumption
September 11, 2026
TLS 1.3 collapsed the handshake to a single round trip, but the real latency win for repeat visitors comes from resumption. A client presenting a valid pre-shared key can skip straight to encrypted application data, which on mobile networks can be the difference between a page that feels instant and one that feels broken.
The trade-off lives in forward secrecy. Tickets encrypted with a long-lived server key mean captured traffic can be decrypted later if that key leaks. Operators who care rotate ticket keys on a strict cadence - daily is common, hourly is not crazy - and accept the small CPU cost of more full handshakes.
A Field Guide to Graceful Degradation
May 17, 2026
Architectures need an explicit hierarchy of failure. Recommendation engines should yield before purchasing flows break; query auto-complete should disable before search fails; generated previews should drop before source content vanishes. Formulating this priority map and reinforcing it through isol…
The Operator's Guide to Load Testing
August 13, 2026
Benchmark simulations repeatedly fail to anticipate live incidents because synthetic request topologies overlook messy reality. Evenly distributed traffic aimed at single endpoints provides isolated micro-benchmarks. Real degradation occurs when synchronized retry floods slam backends after a moment…
The Hidden Cost of Chatty Microservices
July 30, 2026
Splitting a monolith into services trades local complexity for distributed complexity, and nowhere is that clearer than in fan-out. A request that used to make three function calls now makes three network calls, each with its own timeout, retry policy, and failure mode.…
Data Residency Basics for Global Teams
August 3, 2026
Data residency questions arrive late in most projects, usually phrased as: can you just keep EU customer data in the EU? The honest answer is that 'just' is doing enormous work in that sentence, because residency is not a hosting decision but an architecture decision.…
More reading
- What Good Observability Actually Looks Like — Operations, August 21, 2026
- Multi-Region Failover Planning — Operations, April 18, 2026
- A Practical Guide to API Rate Limiting — Engineering, May 26, 2026
About us
We cover the unglamorous middle of software: queues that back up, caches that lie, and DNS at 3 a.m. Everything is written from real operational experience.