Freelance MySQL/PostgreSQL DBA

Fieldside; Brussel Hoofdstad; Sur place; EUR 85 000 - 120 000; Temps partiel

Résumé du poste

Fieldside is seeking an Operational DBA in Belgium to own and improve MySQL and PostgreSQL backends. You will ensure high availability, security, and predictable performance while managing backups and DR runbooks.

You will optimize queries, manage replication, and enforce RBAC across DEV/UAT/PROD environments, collaborating with application and infra teams to maintain posture.

Qualifications

• 5+ years hands-on experience with MySQL or PostgreSQL in production
• 2+ years using the second database technology (MySQL or PostgreSQL)
• Strong knowledge of backup/restore tools and PITR
• Experience with performance tuning and query optimization
• Linux system administration and shell scripting (Bash/Python/Perl)
• Security best practices, RBAC, audit/logging

Responsabilités

• Provide operational ownership for MySQL and PostgreSQL backends
• Ensure high availability, reliability, and recoverability
• Manage backups (mysqldump, pg_dump, XtraBackup, basebackups) and PITR
• Monitor performance, analyze locks/waits, and tune databases
• Coordinate with app and infra teams, maintain dev/stage/prod parity
• Implement HA architectures (streaming replication, InnoDB Cluster, Group Replication)
• Enforce security controls and least-privilege access
• Perform RCA for critical incidents and drive improvements

Connaissances

Senior DBA

Cloud/On-Prem

Automation scripting

Linux admin

Security & compliance

Performance tuning

Root cause analysis

Cross-functional collaboration

Documentation

Outils

MySQL

PostgreSQL

pgvector

pg_basebackup

mysqldump

MySQL Shell

Percona XtraBackup

WAL archiving

pg_dump/pg_dumpall

ProxySQL

HAProxy

Kubernetes

Description du poste

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

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

Query performance analysis and optimization:

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

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

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

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

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

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

Details

Hybride

CONTRIBUTE

Freelance