Draxelis
Practical engineering writing for people who keep systems alive.
Understanding TLS 1.3 Session Resumption
September 20, 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.
When to Choose a Queue Over a Request
April 22, 2026
Traditional RPC calls remain popular due to straightforward causality: the client makes an invocation, waits for the response, and monitors latency directly. Asynchronous message queuing becomes essential when background tasks outlast active connections or when sudden volume surges threaten to overw…
What Good Observability Actually Looks Like
July 21, 2026
Monitoring consoles sprawl uncontrollably while offering little insight during live incidents. True observability operates under inverted priorities: an on-call engineer gets paged, and telemetry systems must identify the root diff within sixty seconds.…
Structuring DNS for Reliability
May 9, 2026
DNS reliability failures are uniquely embarrassing because the failure mode is global: when your zones stop answering, every health check goes green at the infrastructure layer while the entire product vanishes. The classic mitigation is boring - a secondary provider with independent plumbing.…
Email Deliverability: Authentication Beyond SPF
June 27, 2026
Traditional SPF checking fails to address modern deliverability challenges on its own. While an envelope IP check might succeed, mismatched headers trigger spam filters that prioritize cryptographic DKIM validations and broader DMARC policy rules.…
More reading
- Cache Invalidation Patterns That Survive Traffic — Data, July 19, 2026
- HTTP/3 and QUIC: What Changed for Operators — Networking, September 23, 2026
- Data Residency Basics for Global Teams — Compliance, May 29, 2026
About us
Our contributors have spent years on-call for large platforms. This site collects the playbooks, postmortems and reference material we wish someone had handed us earlier.