ExtractPDF4J Global Build Challenge 2026 is officially open!

[mehulimukherjee]

🚀 ExtractPDF4J Global Build Challenge 2026

ExtractPDF4J is launching a global open-source engineering challenge to expand the Java-native PDF table extraction ecosystem.

This challenge is designed for backend engineers, JVM architects, and document-processing enthusiasts who want to contribute to a production-grade hybrid parsing engine combining:

• Stream-based parsing
• Lattice/grid detection
• OCR-assisted extraction

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🎯 Objective

Strengthen and extend ExtractPDF4J by contributing improvements, optimisations, integrations, or real-world use cases.

Participants must:

1. Fork this repository
2. Select an issue labeled challenge-march-2026
3. Implement the solution in a feature branch
4. Please STAR the repo for maximum reach to the Java ecosystem
5. Submit a Pull Request with tests and documentation

🔎 Browse Challenge Issues:
👉 https://github.com/ExtractPDF4J/ExtractPDF4J/issues?q=label%3Achallenge-march-2026

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🧩 Challenge Tracks

Contribute in one or more of the following areas:

📌 Parser Improvements

Enhance header detection, hybrid strategy logic, multi-page stitching, or cell merging algorithms.

🤖 OCR & Vision Enhancements

Improve lattice detection, debug overlays, preprocessing, or Tesseract configuration.

⚡ Performance Engineering

Introduce multi-threading, benchmarking tools, memory optimisations, or GraalVM support.

🔗 Enterprise Integrations

Spring Boot starter, REST microservice, Kafka ingestion pipeline, Docker deployment examples.

📚 Developer Experience

Improve CLI usability, documentation, test coverage, onboarding flow, or contributor guides.

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🏆 Recognition

Outstanding contributors will be:

⭐ Featured in the main README
🏅 Recognised as Core Contributors
📢 Highlighted in community announcements
📝 Included in a Challenge Highlights publication

🎁 Special Reward

In addition to public recognition, the Best Overall Implementation will receive:

🎉 A 1-Year ChatGPT Plus Subscription (personally sponsored)

This award will be granted based on technical excellence, innovation, code quality, and real-world applicability.

The goal is to encourage serious engineering contributions that push the ExtractPDF4J ecosystem forward.

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📅 Timeline

Challenge Duration: 30 Days
Submission Deadline: 31st March 2026
Results Announcement: 14th April 2026

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📦 Submission Requirements (Must-Haves)

For PRs:

• Clear Description (what/why/how) - Follow the PR Template
• Tests OR clear manual verification steps
• No breaking API changes unless discussed first
• Follow project style and packaging conventions

For demo repos:

• Public repo with README
• Simple run instructions
• Sample input/output
• Link back to ExtractPDF4J

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🧪 Review Process

All PRs will be reviewed. To keep momentum:

• Maintainership will provide initial feedback quickly
• PRs may be asked to add tests/docs
• Smaller, focused PRs merge faster than giant ones

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🧭 Communication

• Use GitHub Issues for work tracking
• Use GitHub Discussions for Q&A and ideas (recommended)
• Tag issues with challenge-2026 + track label

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🧑‍⚖️ Judging Criteria (Scoring)

Each submission is scored out of 100.

1) Technical Correctness & Reliability — 30

• Works as described
• Handles edge cases
• Doesn’t regress existing behavior

2) Real-World Impact — 20

• Solves an actual production pain point
• Improves accuracy, coverage, or stability

3) Code Quality & Maintainability — 15

• Clean design, readable code
• Fits existing architecture
• Minimal complexity for the gain

4) Tests / Verification Quality — 15

• Unit/integration tests preferred
• Or strong reproducible steps with sample artifacts

5) Performance / Efficiency — 10

• Demonstrates measurable improvement where relevant

6) Documentation & Developer Experience — 10

• Usage clarity (README, Javadoc, examples)
• Smooth onboarding

Bonus points:

• Benchmarks + sample corpus
• Diagnostic tooling that helps users debug extraction issues

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✅ Rules (Keep It Fair)

• No plagiarism
• Respect licensing
• Don’t submit malicious code
• If adding new dependencies, explain why
• If you use sample PDFs, ensure you have rights to share them (or use synthetic samples)

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🚀 Getting Started

1. Fork the repo
2. Run existing tests
3. Pick an issue labeled challenge-march-2026
4. Implement a focused PR
5. Submit with proof (tests/benchmarks/examples)

Good luck — and thanks for helping build the JVM PDF extraction ecosystem.

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Let’s build a stronger PDF processing ecosystem for the JVM.

Fork. Build. Contribute. STAR

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