What is a DBA?

DBA stands for Database Administrator: the person who makes sure a company's databases stay available and perform well, without losing data along the way, and that only the right people touch them. It is an infrastructure role, not an analytics one: a DBA does not exploit the data, they make it safe for others to do so.

What a DBA does day to day

• Availability. Keeping the database up and answering. High availability, replicas, failover, maintenance windows.
• Performance. Indexes, execution plans, slow queries, locks. A good part of the job is finding out why something is slow and fixing it without touching the application.
• Backup and recovery. Backup policy and restore drills, including point-in-time recovery. This is what separates an incident from a disaster.
• Security and access. Users, roles, encryption, auditing, compliance.
• Changes and deployments. Schema migrations, version upgrades, cloud moves, capacity.
• Support to development. Reviewing models and queries, advising on indexes, helping when something breaks.

Types of DBA

The label covers fairly different profiles, and it is worth knowing which one describes you before you apply:

• Production or operations DBA. The classic one: critical environments, on-call, many servers. Usually comes from systems administration.
• Development DBA. Closer to the code: modelling, stored procedures, query tuning. Usually comes from backend development.
• DBRE or cloud DBA. Managed databases (Azure SQL, RDS, Cloud SQL), infrastructure as code, automation. More and more common in job ads.

How people become a DBA

Almost nobody starts as a DBA. The two usual paths are from systems administration (you already run servers and backups, and you specialise in the engine) and from backend development (you already write SQL, and you move towards performance and operations). In both cases what makes the difference in an interview is being able to talk through a real incident: what broke and what you changed so it would not happen again.