Freelance MySQL/PostgreSQL DBA

Provide operational ownership and continuous improvement for the MySQL and PostgreSQL backends to ensure:

• High availability and reliability

• Strong security and compliance posture

• Predictable performance and scalability

• Verified backups and recoverability

• Clear monitoring, documentation

Roles and Responsibilities

Operational DBA Duties

• Install, configure, maintain and upgrade standalone and/or clustered instances

  • PostgreSQL 12+

  • MySQL 8.0+

• Perform routine maintenance (schema housekeeping, index maintenance, statistics updates, data retention support).

• Manage users, roles, privileges, and authentication methods according to least-privilege principles.

• Manage storage growth and capacity forecasting (disk usage, table growth trends, partitioning/archiving recommendations).

• Troubleshoot complex production issues including data corruption, replication failures and performance degradation

• Maintain environment consistency across DEV/UAT/PROD where applicable.

• Perform Root Cause Analysis (RCA) for critical incidents

• Coordinate with application and infrastructure teams

Advanced monitoring and performance tuning

• Monitor and analyse database health and performance metrics

  • Lock contention, deadlocks, wait events

  • Replication lag

  • Resource utilization (CPU, memory, I/O)

• Query performance analysis and optimization:

  • PostgreSQL: EXPLAIN (ANALYZE, BUFFERS)

  • MySQL: Query optimization, execution plans, InnoDB tuning

• Index strategy design and maintenance

• Identification and remediation of locking, contention, and deadlocks

• Capacity planning and workload growth forecasting

Implementation and management of backup and recovery strategies

• PostgreSQL

  • Physical backups (pg_basebackup)

  • Logical backups (pg_dump, pg_dumpall)

  • WAL archiving and Point-in-Time Recovery (PITR)

• MySQL

  • Logical and physical backups (mysqldump, MySQL shell, Percona, XtraBackup)

  • Point-in-Time Recovery (binlog-based)

• Both Platforms

  • Backup strategy implementation and validation

  • Periodic backup and recovery testing

Design and operate High Availability & Disaster Recovery solutions

• PostgreSQL

  • Streaming replication (physical and logical)

  • Synchronous and asynchronous replication

• MySQL

  • Asynchronous and semi-synchronous replication

  • High availability architectures (InnoDB Cluster, Group Replication)

• Both Platforms

  • Automated failover and switchover support

  • Disaster recovery documentation and runbooks

Enforce database security best practices

• Role-based access control and privilege management

• Authentication and password policy enforcement

• TLS/SSL encryption

• Audit logging and compliance support

• Security hardening and vulnerability remediation

Maintenance & Lifecycle Management

• Patch management and minor version upgrades

• Major version upgrade planning and execution

• Schema change review and deployment support

• End-of-life planning and platform recommendations

Location: Brussels – 5 days per week onsite – no telework possible

Required Skills

• 5+ years hands-on experience in at least one of the above database technologies (MySQL or PostgreSQL) and 2+ years of experience in the second database technology (MySQL or PostgreSQL)

• MySQL:

  • Strong knowledge of MySQL architecture, storage engines (InnoDB)

  • Hands-on experience with backup tools like mysqldump, MySQL shell, Percona, XtraBackup

• PostgreSQL:

  • Deep understanding of PostgreSQL internals

  • Experience managing large datasets, storage growth, autovacuum and index maintenance

  • Experience with WAL and archiving

  • Experience managing PostgreSQL extensions

• Experience with SQL optimization, indexing, and query execution plans.

• Strong Linux administration skills (system resources, I/O, file systems, network basics) relevant to database performance.

• Knowledge of security best practices (TLS, privilege management, audit/logging, secure configuration).

• Automation mindset: experienced with scripting (Bash/Python/Perl).

Preferred/Advanced skills
MySQL:

• Experience with cloud-managed MySQL platforms (AWS RDS/Aurora, GCP Cloud SQL, Azure Database for MySQL)

• Familiarity with MySQL Shell, Orachestrator, ProxySQL or HAProxy

PostgreSQL:

• Practical experience with pgvector

• Knowledge of HNSW and IVFFlat indexes and their tuning parameters

• Experience with containerized or Kubernetes-based database deployments

• Understanding of pgvector upgrades and compatibility with PostgreSQL versions