Do I need a read replica for a small production PostgreSQL app?

Usually, no — a read replica is often unnecessary for a small production PostgreSQL app.

You probably don’t need one if:

• Your app has modest traffic
• Most queries are writes or mixed read/write
• You can handle brief maintenance windows or use backups for recovery
• Your main concern is cost and simplicity
• Your primary server still has plenty of headroom for CPU, RAM, and I/O

A read replica becomes useful if you need:

• Read scaling: lots of traffic from SELECT queries that starts overwhelming the primary
• High availability / failover: faster recovery if the primary goes down
• Isolation of analytics/reporting: long-running queries shouldn’t slow down the primary
• Geographic latency reduction: serving reads closer to users in another region
• Backup offloading: running heavy exports or reports without impacting writes

For a small app, better first investments are often:

• Proper indexes
• Query optimization
• Connection pooling (e.g. PgBouncer)
• Routine backups and restore testing
• Monitoring slow queries and resource usage
• Upgrading the primary instance if needed

Rule of thumb

If your primary is not close to resource limits and you don’t have a strong HA requirement, start without a replica. Add one only when you can point to a clear need:

• read load is high,
• failover requirements are strict,
• or reporting jobs are hurting production.

If you want, I can help you decide with a quick checklist based on your app’s traffic, query mix, and uptime requirements.