{"slug": "project-leyden", "name": "Project Leyden", "category": "dev-libs", "category_name": "Libraries and frameworks", "description": "", "recommenders": 5, "commenters": 6, "warners": 0, "score": 4.7, "rising": 1.02, "first": "2025-11-20", "latest": "2026-10-18", "why": "interesting work is happening in OpenJDK's Project Leyden", "why_is_quote": true, "has_verdict": false, "sentiment": {"recommend": 5, "neutral": 1, "compare": 0, "warn": 0}, "spark": [1, 0, 1, 0, 1, 0, 0, 0, 0, 1, 0, 1], "listed": true, "loved": [], "caveat": "", "short_quote": "interesting work is happening in OpenJDK's Project Leyden", "kind": "", "icon": true, "domain": "openjdk.org", "github_repo": null, "official_url": "https://openjdk.org/projects/leyden/", "pricing": "", "aliases": ["Project Leyden"], "verdict": null, "praise": [{"label": "", "summary": "", "quotes": [{"id": 802334176, "item_id": 50145886, "url": "https://news.ycombinator.com/item?id=50145886", "by": "cogman10", "date": "2026-10-18", "stance": "recommend", "quote": "you can get pretty decent startup times", "excerpt": "There's ongoing work to improve JVM startup time. [1] So long as you are willing to do a training run, you can get pretty decent startup times. [1] https://openjdk.org/projects/leyden/", "context": "", "use_case": "Faster JVM startup", "switched_from": "", "story": "JDK 28"}, {"id": 788448067, "item_id": 49278004, "url": "https://news.ycombinator.com/item?id=49278004", "by": "za3faran", "date": "2026-08-12", "stance": "recommend", "quote": "You might also want to checkout Project Leyden[1]", "excerpt": "You might want to check out Quarkus, Mirconaut, or Helidon MP. They do build time DI, and are more focused on performance and reduced resource usage. They are similar enough to Spring, and I believe Quarkus and Micronaut have an optional Spring compatibility layer that one can use. LLMs could help with migration if the codebase is well written. You might also want to checkout Project Leyden[1] https://openjdk.org/pro", "context": "", "use_case": "Java startup performance", "switched_from": "", "story": "Why Go Is an Ideal Language for AI-Assisted Software Engineering"}, {"id": 759292320, "item_id": 47455770, "url": "https://news.ycombinator.com/item?id=47455770", "by": "pron", "date": "2026-03-20", "stance": "recommend", "quote": "Leyden has already cut down warmup by a lot", "excerpt": "You mostly need a recent JDK. Leyden has already cut down warmup by a lot and is expected to continue driving it down. https://foojay.io/today/how-is-leyden-improving-java-performance-part-2-of-3/ https://quarkus.io/blog/leyden-1/", "context": "", "use_case": "Faster Java startup", "switched_from": "", "story": "Java Is Fast. Your Code Might Not Be"}, {"id": 743290256, "item_id": 46455641, "url": "https://news.ycombinator.com/item?id=46455641", "by": "NovaX", "date": "2026-01-01", "stance": "recommend", "quote": "This will soften the hard edges so developers can choose their constraints", "excerpt": "Thanks for the corrected evaluation. Just for your awareness, the HotSpot team is working on offering a spectrum of AOT/JIT options under the Leyden project [1]. Currently one has to choose between either a fully open world (JIT) or closed world (AOT) evaluation. The mixed world allows for a tunable knob, e.g. pre-warmup by AOT while retaining dynamic class loading and fast compile times for the application. This wil", "context": "", "use_case": "", "switched_from": "", "story": "2026: The Year of Java in the Terminal"}, {"id": 735849330, "item_id": 45990583, "url": "https://news.ycombinator.com/item?id=45990583", "by": "gunnarmorling", "date": "2025-11-20", "stance": "recommend", "quote": "interesting work is happening in OpenJDK's Project Leyden", "excerpt": "> I never understood why AOT never took off for Java. GraalVM native images certainly are being adopted, the creation of native binaries via GraalVM is seamlessly integrated into stacks like Quarkus or Spring Boot. One small example would be kcctl, a CLI client for Kafka Connect (https://github.com/kcctl/kcctl/). I guess it boils down to the question of what constitutes \"taking off\" for you? But it's also not that na", "context": "", "use_case": "", "switched_from": "", "story": "Implementation of a Java Processor on a FPGA (2016)"}]}], "caveats": [], "who": [], "tags": [], "use_cases": ["faster jvm startup", "java startup performance", "faster java startup"], "compared": [], "makers": [], "threads": [{"url": "https://news.ycombinator.com/item?id=47454384", "title": "Java Is Fast. Your Code Might Not Be", "mentions": 2}, {"url": "https://news.ycombinator.com/item?id=50135379", "title": "JDK 28", "mentions": 1}, {"url": "https://news.ycombinator.com/item?id=49261133", "title": "Why Go Is an Ideal Language for AI-Assisted Software Engineering", "mentions": 1}, {"url": "https://news.ycombinator.com/item?id=46445229", "title": "2026: The Year of Java in the Terminal", "mentions": 1}, {"url": "https://news.ycombinator.com/item?id=45989650", "title": "Implementation of a Java Processor on a FPGA (2016)", "mentions": 1}], "sentiment_by_month": {"2025-11": {"recommend": 1}, "2025-12": {}, "2026-01": {"recommend": 1}, "2026-02": {}, "2026-03": {"recommend": 1, "neutral": 1}, "2026-04": {}, "2026-05": {}, "2026-06": {}, "2026-07": {}, "2026-08": {"recommend": 1}, "2026-09": {}, "2026-10": {"recommend": 1}}, "quotes": [{"id": 802334176, "item_id": 50145886, "url": "https://news.ycombinator.com/item?id=50145886", "by": "cogman10", "date": "2026-10-18", "stance": "recommend", "quote": "you can get pretty decent startup times", "excerpt": "There's ongoing work to improve JVM startup time. [1] So long as you are willing to do a training run, you can get pretty decent startup times. [1] https://openjdk.org/projects/leyden/", "context": "", "use_case": "Faster JVM startup", "switched_from": "", "story": "JDK 28"}, {"id": 788448067, "item_id": 49278004, "url": "https://news.ycombinator.com/item?id=49278004", "by": "za3faran", "date": "2026-08-12", "stance": "recommend", "quote": "You might also want to checkout Project Leyden[1]", "excerpt": "You might want to check out Quarkus, Mirconaut, or Helidon MP. They do build time DI, and are more focused on performance and reduced resource usage. They are similar enough to Spring, and I believe Quarkus and Micronaut have an optional Spring compatibility layer that one can use. LLMs could help with migration if the codebase is well written. You might also want to checkout Project Leyden[1] https://openjdk.org/pro", "context": "", "use_case": "Java startup performance", "switched_from": "", "story": "Why Go Is an Ideal Language for AI-Assisted Software Engineering"}, {"id": 759438945, "item_id": 47464934, "url": "https://news.ycombinator.com/item?id=47464934", "by": "gf000", "date": "2026-03-21", "stance": "neutral", "quote": "and https://openjdk.org/jeps/483 (and in general, project Leyden)", "excerpt": "> can't freeze/resume the state I mean, both of your points are a thing, see https://www.azul.com/products/components/falcon-jit-compiler/ for LLVM as a JIT compiler and https://openjdk.org/jeps/483 (and in general, project Leyden)", "context": "", "use_case": "", "switched_from": "", "story": "Java Is Fast. Your Code Might Not Be"}, {"id": 759292320, "item_id": 47455770, "url": "https://news.ycombinator.com/item?id=47455770", "by": "pron", "date": "2026-03-20", "stance": "recommend", "quote": "Leyden has already cut down warmup by a lot", "excerpt": "You mostly need a recent JDK. Leyden has already cut down warmup by a lot and is expected to continue driving it down. https://foojay.io/today/how-is-leyden-improving-java-performance-part-2-of-3/ https://quarkus.io/blog/leyden-1/", "context": "", "use_case": "Faster Java startup", "switched_from": "", "story": "Java Is Fast. Your Code Might Not Be"}, {"id": 743290256, "item_id": 46455641, "url": "https://news.ycombinator.com/item?id=46455641", "by": "NovaX", "date": "2026-01-01", "stance": "recommend", "quote": "This will soften the hard edges so developers can choose their constraints", "excerpt": "Thanks for the corrected evaluation. Just for your awareness, the HotSpot team is working on offering a spectrum of AOT/JIT options under the Leyden project [1]. Currently one has to choose between either a fully open world (JIT) or closed world (AOT) evaluation. The mixed world allows for a tunable knob, e.g. pre-warmup by AOT while retaining dynamic class loading and fast compile times for the application. This wil", "context": "", "use_case": "", "switched_from": "", "story": "2026: The Year of Java in the Terminal"}, {"id": 735849330, "item_id": 45990583, "url": "https://news.ycombinator.com/item?id=45990583", "by": "gunnarmorling", "date": "2025-11-20", "stance": "recommend", "quote": "interesting work is happening in OpenJDK's Project Leyden", "excerpt": "> I never understood why AOT never took off for Java. GraalVM native images certainly are being adopted, the creation of native binaries via GraalVM is seamlessly integrated into stacks like Quarkus or Spring Boot. One small example would be kcctl, a CLI client for Kafka Connect (https://github.com/kcctl/kcctl/). I guess it boils down to the question of what constitutes \"taking off\" for you? But it's also not that na", "context": "", "use_case": "", "switched_from": "", "story": "Implementation of a Java Processor on a FPGA (2016)"}]}