CZJUG Prague · Agentic Development and Debugging with Java

Will Java survive the age of AI project builders?

A subjective field report from building side projects with agents

Vladimír Oraný · CZJUG Prague · May 25, 2026

About me

Vladimír Oraný

Principal Software Engineer at Agorapulse
Java, backend systems, developer tooling
Building side projects with agents: Claude, OpenClaw, Hermes
Writing at telegraphic.dev
Subscribe at telegraphic.substack.com

Agenda

Building with Agents

Brick Directory
- Claude and Spring Boot
Pikarama
- OpenClaw and Next.js

Java and Agents

Agent’s First Choices
Agentic Dictionary
Java and Skills
Java’s Opportunity

Agenda

Disclaimer

Subjective

My field report.

Uncomfortable

Not reassurance.

Java

Not Kotlin.

Building with Agents

Brick Directory

Claude and Spring

Brick Directory

MCP Server for AFOLs

Google Sheet → AFOL Sites

BrickLink

Rebrickable

Model Context Protocol

Brick Economy

BrickOwl

Leveraging my knowledge

Claude with Spring AI

Spring

React

Terraform

AWS

Brick Directory

The final result

Brick Directory

Timeline

September

Project skeleton Spring Boot, React, first MCP server, Rebrickable data, AFOL API clients

October

Product shape Chat UI, admin tools, user preferences, Playwright E2E, search, public website

November

Integrations hardening OAuth flows, command-pattern cleanup, MCP metadata, BrickOwl inventory, CSV exports

December

Polish and content Analytics consent, conversation export, Spring AI update, SEO, blog tooling

February

Reality check AWS teardown, Docker images, Coolify deployment

Brick Directory

Costs

Building with Agents

Pikarama

OpenClaw and Next.js

Pikarama

Made Overnight with OpenClaw

Pikarama

Integrations

Telegram
Slack
REST API
CLI

Pikarama

The Final Result

Pikarama

Timeline

Tuesday First usable app Spec → app skeleton → backend and frontend → notifications, i18n, auth, landing page, Telegram.

Wednesday Telegram hardening Bot UX, callback limits, translated bot strings, auth providers.

Thursday API and Slack Slack integration, public REST API, OpenAPI docs, API tokens, Playwright setup.

Friday Slack reality Modal flows, 3-second timeout fixes, waitUntil, DM fallback, E2E cleanup.

Saturday Voting model Multi-vote, multi-pick, pass flow, repeat command, Telegram finalization.

Sunday Slack catches up Multi-pick and multi-vote in Slack, autocomplete, duplicate-notification fixes, E2E coverage.

Pikarama

Costs

€0.00

Vercel
Neon

€31.99

Hetzner
Coolify

Two builds, two modes

Application comparison

	Brick Directory	Pikarama
Agent	Claude	OpenClaw
Tech stack	Spring	Next.js
Time	5 months	1 week
Costs	$999.99	€31.99

Java and Agents

Java is not Dead

Java and Agents

Cobol is not Dead

Java and Agents

Cobol is Clinically Dead

Small experiment

Build me a Pet Clinic

user$ Build me a pet clinic app where owners can book appointments for their pets.

agent$ Sure. Creating the application...

Small experiment

Hermes Agent

Small experiment

Lovable

Small experiment

Macaly

Harness decides

None picked Java

Java and Agents

Agentic Dictionary

Java Agents

Language Model

Framework Harness

Library Skill

Application Agent

Skills · skills.sh #26 · 250.7K installs

Skills enable Agents

$ tree -L 2 skill-creator
skill-creator
├── agents
│   ├── analyzer.md
│   ├── comparator.md
│   └── grader.md
├── assets
│   └── eval_review.html
├── eval-viewer
│   ├── generate_review.py
│   └── viewer.html
├── references
│   └── schemas.md
├── scripts
│   ├── package_skill.py
│   ├── quick_validate.py
│   ├── run_eval.py
│   └── run_loop.py
└── SKILL.md

source: anthropics/skills/skill-creator

Skills

Java Sidecar Scripts

Requires Java installed
Must be self-contained
Never seen one
GraalVM would feel big

Agents

Fast Feedback Required

generate

lint

compile

test

fix

Agents

Zero Language

zero check <input>parse, typecheck, diagnostics zero run <input>build and run executable zero test <input>run inline tests zero fmt <input>format source, --check in CI zero build <input>emit executable or object zero ship <input>release preview, checksums, metadata zero graph <input>modules, symbols, capabilities zero size <input>artifact size and budgets zero doc <input>public API documentation facts zero fix --plan --json <input>typed repair plan zero doctorhost and target readiness

source: zerolang.ai/cli

Agents

Java Ecosystem

./mvnw testor ./gradlew test, Surefire/Failsafe, JUnit 4/5 ./mvnw compileor ./gradlew classes, javac, module path ./mvnw packageor ./gradlew build, bootJar, shadowJar, native java -jar target/*.jaror ./gradlew bootRun, exec plugin, app plugin ./mvnw spotless:checkor Spotless, Checkstyle, PMD, SpotBugs ./mvnw dependency:treeor Gradle dependencies, jdeps, enforcer jdeps target/*.jarmodules, split packages, runtime image javadoc -d docs …Javadoc, OpenAPI, Spring REST Docs java -jar target/*.jarclasspath, module path, profiles, env vars docker build -t app .or Jib, Buildpacks, layered jars, native image java -versionJAVA_HOME, SDKMAN, asdf, toolchains, wrappers

Agents

Python Ecosystem

uv run app.pyrun with managed env and deps uv syncinstall from lockfile uv add fastapiadd dependency uvx ruff check .lint fast uvx ruff format .format fast uv run pytesttest command is obvious uv buildbuild package uv publishpublish package uv python installinstall runtime uv treedependency graph uv tool run …one-shot tools without project setup

Java's Opportunities

Java’s Opportunity

The Agentic Web

Agents hate JavaScript
Agents love Markdown and CLIs
Users love voice messages and images
Users hate copy-pasting

And that's why I asked

Will Java survive the age of AI project builders?

Thank you.

Discussion

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