A Java Geek weekly 131

Clean your Memory: From Finalize to Cleaner. Monitor Claude Code Usage With Grafana. I Read the Leaked Claude Code Source — Here’s What I Found. Don’t trust, verify. Encoding Team Standards. Claude Code Rules Directory: Modular Instructions That Scale. Agentic AI Patterns Reinforce Engineering Discipline. Email obfuscation: What works in 2026?. The hidden technical debt of agentic engineering. Announcing a Kotlin Multiplatform API and SDK for OpenTelemetry.

• 2 min read
Clean your Memory: From Finalize to Cleaner

Garbage collection in Java takes care of memory management, but it does not clean up non-memory resources like sockets or file handles. Resource leaks may occur without proper management, leading to performance degradation or crashes. Java’s Cleaner API, introduced in Java 9, provides a modern and efficient mechanism for resource cleanup when objects are no longer reachable. It addresses the shortcomings of the deprecated finalize() method, offering a predictable and efficient way to manage non-memory resources, such as file handles, database connections, or native memory.

Monitor Claude Code Usage With Grafana

OpenTelemetry meets Claude Code! I want to try, especially with some people around me having told that the token burn token has skyrocketed for no reason.

I Read the Leaked Claude Code Source — Here’s What I Found

You might have learned that Anthropic leaked the source code. Someone was fast enough to get his hands on it and did analyze the assistant. Remember: the model behind might be the same, but prompting two different assistants, e.g., GitHub Copilot and Claude Code, with the same task will likely result in very different outcomes. Most of the value lies in the client.

Don’t trust, verify

I’d recommend that any CI pipeline you design uses a hash instead of a mutable version (e.g., GitHub Actions, Docker images, etc.). For regular binaries, every provider worth its salt provides a hash of the binary that you must compare with your own hashing. It’s basic hygiene, not a nice-to-have.

Encoding Team Standards

If you’re using a coding assistant inside your team, writing down the knowledge of your senior developers is the thing to do. It seems an evidence, but I wonder how many do it.

Claude Code Rules Directory: Modular Instructions That Scale

In my previous newsletter, I listed a post titled "Anatomy of .claude folder". It mentioned the /rules folder I never heard about. I checked the Claude Code documentation with no success. The link above is the best reference I could get. Worth knowing.

Agentic AI Patterns Reinforce Engineering Discipline

Duvall and Stack both highlighted that AI assisted development requires a mix of shift left practices and shift right feedback, where behavioural definitions and production state become part of the validation process. Duvall also noted the advantages of AI analysing production telemetry more expansively to identify patterns and surface issues earlier.

Email obfuscation: What works in 2026?
  • No protection: blocked 0%
  • HTML Entities: blocked 95%
  • HTML Comments: blocked 98%
  • HTML SVG: blocked 100%
  • CSS Display none: blocked 100%
  • JS Concatenation: blocked 100%
  • JS Rot18: blocked 100%
  • JS Conversion: blocked 100%
  • JS AES encryption: blocked 100%
  • JS User interaction: blocked 100%
  • HTML Symbol substition: breaks usability
  • HTML Instructions: breaks usability
  • HTML Image: breaks usability
  • CSS Content: breaks usability
  • CSS Text direction: breaks usability
The hidden technical debt of agentic engineering

Agents are easy to build but hard to run. We mapped seven blocks of hidden infrastructure debt with AI agents in enterprise systems.

  • Integrations
  • Context lake
  • Agent registry
  • Measurement
  • Human-in-the-loop
  • Governance
  • Orchestration
Announcing a Kotlin Multiplatform API and SDK for OpenTelemetry

In recent years, client-side and mobile observability has become an area of increasing focus within the OpenTelemetry community, particularly for teams building applications in Kotlin and Kotlin Multiplatform (KMP). In 2025, Embrace, a user-focused observability platform and active OpenTelemetry contributor, opened a proposal to contribute a Kotlin implementation of the OpenTelemetry specification to the community.

9 Things You’re Overengineering (The Browser Already Solved Them)
  • Let me just run this later → requestIdleCallback
  • Why is my input not highlighting??? → :focus-within
  • Let’s show offline mode → navigator.onLine
  • Smooth animation, but make it cursed → requestAnimationFrame
  • This card should adapt… but only here → container queries
  • Random ID, what could go wrong? → crypto.getRandomValues
  • We need a modal → <dialog>
  • Voice input would be cool…​ → Speech API
  • Will this CSS explode? → @supports