I’m Denys Miasnychenko, a platform engineer and software architect in the Chicago area. I’ve worked in IT for over 25 years, most of it running infrastructure in production.
Today I’m a Senior Software Architect at OpticsPlanet, where I work on logging and observability, Kubernetes and service mesh, cloud cost, and the infrastructure that lets engineering teams use LLM agents.
What I work on
- Elasticsearch and the ELK stack at scale: ingestion, migrations, sizing, tooling
- Kubernetes (EKS, RKE2) and Istio across cloud and on-prem
- Metrics and tracing: Prometheus, VictoriaMetrics, OpenTelemetry, Grafana
- LLM agent infrastructure: MCP servers, Claude Code configuration, AI usage monitoring
- Making infrastructure cheaper without making it fragile
Open source
- epm: a terminal dashboard for live Elasticsearch cluster performance. Single Go binary, works with ES 6.x to 9.x.
- zed-haproxy: HAProxy support for the Zed editor: syntax highlighting, outline, go to definition and find references for backends and ACLs. Built on my own tree-sitter grammar for HAProxy configs.
Writing
I write rarely, when something took long enough to figure out that it seems worth writing down. All articles.
- Head-of-line blocking: how one dead output stalled a Logstash pipeline
A production incident write-up: one dead Elasticsearch output wedged a whole Logstash pipeline with a persisted queue, and how it was detected, fixed and drained.
- Metrics vs Logs: where it lives and what it costs
How I decide whether a field belongs in a time-series database or a log store, measured on a day of real e-commerce edge traffic.
- Non-Determinism Doesn't Matter If the Tests Are Strict Enough
Why LLM non-determinism stops mattering once the spec and the tests pin down the required behavior, and where the remaining variance comes from.
- Keeping an LLM honest about what it doesn't know
A three-layer setup (a SessionStart hook, verification rules and claude.ai preferences) that makes Claude check current facts instead of answering from stale training data.
- epm: watching an Elasticsearch cluster from the terminal
Why I wrote epm, a terminal dashboard for Elasticsearch, and how it turns cumulative counters into rates without an Elasticsearch client library.