What pool size formula does HikariCP recommend?

(core_count * 2) + effective_spindle_count. For SSD Postgres on 4 cores: 9-10.

How do I fix N+1 in Spring Boot JPA?

Use @EntityGraph on repos or LEFT JOIN FETCH in queries. Profile with Hibernate stats.

Only after profiling CPU/IO mix. IO-heavy? Defaults rock. CPU? Fewer, beefier.

AI spits out flawless CRUD. But it won't warn you when 200 threads choke your 6-core server. Here's the human intel that saves outages.

DevTools Feed Apr 03, 2026 3 min read 10 views

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#HikariCP #N+1 problem #Spring Boot #backend engineering #thread pooling

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