Senior Database Administrator (MariaDB/MySQL)

About Us

We are a Bulgarian technology company with over 25 years of experience, behind numerous pioneering digital products, including Bulgaria’s first internet cards and the country’s first interactive television game. Today, the company continues to develop innovative software solutions, online platforms and original digital products, combining technological expertise, creativity and out-of-the-box thinking.

We are looking for a Senior Database Administrator who can operate and evolve large-scale, high-throughput database environments.

In this role, you will oversee the installation, monitoring, optimization, and continuous improvement of all database clusters powering our high-traffic online platforms. Our systems routinely serve massive volumes of parallel HTTP and SQL requests, where client-visible latency must stay within 100-200 ms. Ensuring stability, consistency, and predictable performance under heavy load is at the core of your work.

Responsibilities

• Build and deploy new MariaDB/MySQL clusters optimized for scale, durability, and zero-downtime operations.
• Perform daily high-level health checks, monitoring, and proactive performance tuning across all database nodes.
• Analyze slow queries and provide clear optimization strategies – schema design adjustments, indexing improvements, query rewrites, and partitioning decisions.
• Continuously monitor and tune query throughput (QPS/TPS), concurrency behavior, and IO performance with the goal of increasing capacity while lowering response times.
• Maintain, refine, and troubleshoot Galera Cluster environments with a focus on high availability and seamless failover.
• Monitor OS-level subsystems (CPU, IO, memory, NUMA behavior, and disk latency) and correlate them with database workload patterns.
• Develop strategies that reduce load on the primary database layer: caching, sharding, connection pooling, read/write split, and hot-path query reduction.
• Ensure schema changes and major upgrades are executed with minimal or zero downtime.
• Produce clear documentation, capacity-planning reports, and actionable recommendations for engineering teams.

Qualifications

• 3+ years of hands-on experience managing MariaDB/MySQL databases at scale.
• Deep understanding of MariaDB/MySQL internals and the InnoDB storage engine (locking, latching, MVCC, buffer pool behavior, redo/undo logs, flushing).
• Solid understanding of the MySQL/MariaDB optimizer, execution plans, and cost-based query analysis.
• Strong knowledge of indexing strategies and join algorithms, and their impact on large datasets under concurrent workloads.
• Experience operating and troubleshooting Galera Cluster replication, quorum, and state transfer mechanics.
• Ability to analyze performance across all layers: SQL, storage engine, OS, hardware.
• Strong analytical skills and an interest in solving complex scaling challenges.
• Excellent communication, presentation, and collaboration skills.
• Self-driven, disciplined, and comfortable working in fast-paced, results-oriented environments.

Advantages

• Experience with Unix-based operating systems (FreeBSD, Linux, etc.).
• Hands-on experience with large MariaDB/MySQL Galera deployments.
• Familiarity with scripting/programming languages: Perl, PHP, Python, Ruby, Bash.
• Experience working with extremely large servers (“monster servers”) and complex multi-node architectures.
• Strong sense of ownership, precision, and reliability.

What We Offer

• Competitive remuneration that reflects your experience and expertise.
• Private health insurance (including dental).
• Multisport card.
• Food vouchers.
• Class A office environment and a positive, collaborative culture.
• Convenient office location.
• A collaborative team culture that values technical expertise and knowledge-sharing.
• Opportunities for continuous learning and professional development.

Interested? Send us your CV.