Notes from the field — Kafka, Kubernetes, Go, and the systems around them.https://devgeist.com/blog/enhttps://devgeist.com/blog/kubernetes-control-theory-part-1/https://devgeist.com/blog/kubernetes-control-theory-part-1/Exploring Kubernetes HPA through control theory: dead time, windup, offset — and why HPA's math is smarter than it looks.Wed, 13 May 2026 00:00:00 GMTkubernetescontrol-theoryautoscalinghpaMyroslav Vivcharykhttps://devgeist.com/blog/kafka-ordered-retries-3/https://devgeist.com/blog/kafka-ordered-retries-3/The operational cost of maintaining message ordering in Kafka with distributed locks — and when simpler alternatives are the better choice.Tue, 24 Mar 2026 00:00:00 GMTkafkadistributed-systemsgoarchitectureMyroslav Vivcharykhttps://devgeist.com/blog/kafka-ordered-retries-2/https://devgeist.com/blog/kafka-ordered-retries-2/Implementation gaps in Kafka's ordered retry pattern: the per-key locking edge cases and production bugs the whiteboard diagrams don't show.Tue, 17 Mar 2026 00:00:00 GMTkafkadistributed-systemsgoarchitectureMyroslav Vivcharykhttps://devgeist.com/blog/kafka-ordered-retries-1/https://devgeist.com/blog/kafka-ordered-retries-1/Retry topics keep throughput high but break ordering. Learn why Kafka retries fail for stateful systems and how to maintain message order.Tue, 10 Mar 2026 00:00:00 GMTkafkadistributed-systemsgoarchitectureMyroslav Vivcharykhttps://devgeist.com/blog/ghost-in-the-database/https://devgeist.com/blog/ghost-in-the-database/A production debugging story: how an empty MySQL table took 20 seconds to query, and what InnoDB's history list taught me about MVCC and purge operations.Tue, 03 Feb 2026 00:00:00 GMTmysqldatabasesperformanceinnodbMyroslav Vivcharykhttps://devgeist.com/blog/go-graceful-shutdown-pattern/https://devgeist.com/blog/go-graceful-shutdown-pattern/Master graceful shutdown in Go beyond ctx.Done(). Two-phase shutdown pattern for message queues (SQS, Kafka, RabbitMQ), transactions, and batch jobs.Tue, 13 Jan 2026 00:00:00 GMTgoconcurrencyMyroslav Vivcharykhttps://devgeist.com/blog/kafka-consumer-health-checks/https://devgeist.com/blog/kafka-consumer-health-checks/Stop getting false alerts from Kafka consumers. This guide shows you how to measure progress instead of lag, with a production-ready Go library.Sun, 14 Dec 2025 00:00:00 GMTkafkagoobservabilitydistributed-systemsMyroslav Vivcharykhttps://devgeist.com/blog/api-testing-simulations-2/https://devgeist.com/blog/api-testing-simulations-2/Real-world API simulation challenges beyond the basics: dynamic data, stateful interactions, and the edge cases that break naive record-and-replay setups.Sun, 23 Mar 2025 00:00:00 GMTtestinggoapihoverflyMyroslav Vivcharykhttps://devgeist.com/blog/api-testing-through-simulations/https://devgeist.com/blog/api-testing-through-simulations/Why mock when you can simulate? Discover how to capture real API behavior and replay it in your tests to save costs, reduce latency, and improve reliability.Sun, 23 Feb 2025 00:00:00 GMTtestinggoapihoverflyMyroslav Vivcharyk