Index: backend/src/main/resources/application.properties
===================================================================
--- backend/src/main/resources/application.properties	(revision e9a0543bbb622a2b343d1f5fe3b2df7ddb6a0bd3)
+++ backend/src/main/resources/application.properties	(revision 194c01621e96510fb6f238b2098a64b3663ec780)
@@ -43,7 +43,8 @@
 spring.datasource.hikari.pool-name=trekrHikariPool
 # Remote PostgreSQL (especially via SSH tunnel) often has a small max_connections.
-# Use conservative defaults to avoid exhausting connection slots; override via env if needed.
-spring.datasource.hikari.maximum-pool-size=${SPRING_DATASOURCE_HIKARI_MAX_POOL_SIZE:4}
-spring.datasource.hikari.minimum-idle=${SPRING_DATASOURCE_HIKARI_MIN_IDLE:0}
+# Use a slightly larger default so the app can serve more concurrent users without
+# overloading the database; override via env if your provider has tighter limits.
+spring.datasource.hikari.maximum-pool-size=${SPRING_DATASOURCE_HIKARI_MAX_POOL_SIZE:20}
+spring.datasource.hikari.minimum-idle=${SPRING_DATASOURCE_HIKARI_MIN_IDLE:5}
 spring.datasource.hikari.connection-timeout=30000
 spring.datasource.hikari.idle-timeout=600000