Actuator /env: what changes when show-values is enabled
Correction: Spring Boot 3+ hides values by default. Start with the exact version and effective show-values configuration.
Sep 11 2026 · 2′ · Tutorials · spring-boot · java
Tag: java
19Pinning in Virtual Threads: The Two Real Cases According to JEP 444
Yesterday I left a detail hanging: it's not that "something" blocks the carrier thread. There are exactly two scenarios, documented in JEP 444, and if you migrate legacy code without knowing them, pinning is going to explain why your virtual thread pool isn't scaling the way you expected.
Aug 28 2026 · 7′ · Tutorials · concurrencia · java
Actuator Endpoints in Spring Boot: Allowlist, Don't Just Disable the Obvious Ones
Spring Boot Actuator exposes more by default than most teams realize. The difference between an endpoint that's useful for monitoring and a map of environment variables handed to an attacker comes down to a decision almost nobody makes explicitly: allowlist versus disabling what looks obvious.
Aug 23 2026 · 8′ · Tutorials · spring-boot · java
What It Means to Be a Java Champion in 2026: The Real Criteria Behind the Recognition and Why I Care
Java Champion isn't an academic title or a corporate badge. It's recognition of community contribution — and in 2026, quality technical content in Spanish is an undervalued and completely legitimate contribution. My declared goal and the real criteria behind the program.
Aug 18 2026 · 10′ · Tutorials · open source · spring-boot
CAdES vs XAdES Digital Signatures in Java: The Differences That Matter When Your CA Asks for One and You've Built the Other
CAdES and XAdES aren't interchangeable even though both are "advanced signatures." The choice depends on document type, trust profile, and what the CA actually expects to validate. A technical guide with DSS and Java to make the right call before you sign anything.
Aug 12 2026 · 9′ · Tutorials · seguridad · certificados
Virtual Threads Won't Save You From a Badly Placed synchronized
Virtual Threads solves the cost of spinning up thousands of threads in the JVM. It doesn't solve the blocking problem when your code has synchronized blocks or blocking native calls. JEP 444 says so, but almost nobody reads it to the end.
Aug 11 2026 · 8′ · Tutorials · concurrencia · spring-boot
Spring Boot Actuator: What to Expose, What to Hide, and What to Check Before Adding Endpoints
Actuator isn't the problem. Enabling it without a clear exposure policy is. A practical guide to using it as an operational tool without turning it into unnecessary public attack surface.
Jun 17 2026 · 8′ · Tutorials · devops · backend
Digital identity backend architecture: the decisions tutorials skip
Auth tutorials show you the happy path. The real problems in digital identity show up in revocation, state-change propagation, and the trust model. A decision guide from the inside.
May 30 2026 · 9′ · Tutorials · backend · seguridad
Digital signatures: format, certificate, and validation policy — three layers people constantly mix up
When a digital signature fails, the instinct is to look at cryptography. Most of the time the problem is format or validation policy. Here I separate the three layers so the next error doesn't cost you hours.
May 29 2026 · 10′ · Tutorials · seguridad · certificados