Java 21 is already running in production for ~50% of attendees.

Breakdown from the poll: 8% on 8 or older, 25% on 11/17, 49% on 21, 12% on 24/25.

WHY TEAMS MOVE FORWARD

1️⃣ Pros of upgrading JDK (→ 21 or 25)

- 🚀 Noticeable performance gains (JIT/GC, vector API, Loom/virtual threads in 21).

- 🛡️ Longer support horizons and security baselines.

- 🔧 Modern language features: pattern matching, records, sealed classes, string templates (25), simpler concurrency.

- 🧩 Healthier ecosystem—frameworks, libs, and tooling target LTS+ quickly.

- 💸 Lower infra costs via better throughput and memory efficiency.

CONS / HEADWINDS

- 🧪 Migration & regression testing effort (build plugins, CI, containers).

- 🔄 Dependency lag (some libs/plugins may trail a release).

- 🧰 Toolchain updates (JDK images, container base, buildpacks).

- 🧑‍🏫 Team ramp-up on new features & GC/concurrency knobs.

PRAGMATIC PATH

- If you’re on 8/11/17 ➜ plan a step to 21 (LTS) now.

- If you’re already on 21 ➜ pilot 25 on a canary or non-critical service to capture perf/feature wins, then roll forward when your stack is ready.

- Automate compatibility checks (Revapi/japicmp), run dual-JDK CI, and keep a “known-good” container image per service.

🗣️“The most dangerous phrase in the language is, ‘We’ve always done it this way.’” — Grace Hopper

Progress in Java keeps paying compounding interest—ship safer, faster, and cleaner code.

#Java25 #Java21 #JDK #Performance #SoftwareEngineering #TechLeadership #Migration #CloudNative #SpringBoot #Kafka