Krzysztof K.

Senior MySQL & MariaDB database reliability engineer with 15+ years of production experience. I help software teams and agencies find out why their database is slow or fragile, and leave them with a clear, prioritised plan. What I work on • Performance investigations: slow queries, locking and deadlocks, unexplained latency, configuration and capacity reviews • Amazon Aurora and MySQL: major version upgrades, sharding, schema and query work with development teams • High availability: replication, Galera Cluster, InnoDB Cluster, ProxySQL, MaxScale and HAProxy • PostgreSQL alongside MySQL: PgBouncer, Pgpool and mixed MySQL/PostgreSQL environments • AWS and on-premises environments, Linux, Docker and Kubernetes Background • Database reliability engineer on a large Amazon Aurora fleet since 2025 • Head of Support at Severalnines (2019–2025), after four years there as a senior support engineer, handling complex MySQL and MariaDB escalations • Earlier: senior MySQL DBA for remote DBA consultancies, and in-house MySQL operations • Database trainings for engineers, technical guides, webinars and a Percona Live Europe talk on MySQL load balancers How I work Fixed scope where possible: one environment, one main question, with the fee and schedule agreed up front. You get findings with their supporting evidence, prioritised recommendations, a plan for validating changes and a technical handover to your team. I also join agency projects as the database specialist while your team keeps delivery ownership. Good fit: slow queries you can't explain, a risky upgrade or migration you want reviewed, replication or Galera trouble, or an HA design you want checked before it goes to production.