archive/phase_reports/audits/hardening-final-report.md

NLP-3.5 Hardening — Final Report

Date: 2026-06-18
Sprint Status: ✅ COMPLETE

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Summary

All 9 tasks completed. The NLP pipeline is now production-hardened.

Task	Description	Status
1	Performance breakdown	✅ Measured per-stage
2	Timing instrumentation	✅ timing_ms in response
3	Smart text processing	✅ AraSpell skipped for >300 chars
4	Priority system	✅ grammar(3) > punctuation(2) > spelling(1) > autocomplete(0)
5	Global overlap resolver	✅ Span collision detection (exact + partial)
6	AutoComplete hooks	✅ Priority=0 registered
7	Stress test	✅ All sizes pass (50-2000 chars)
8	API validation	✅ 5/5 schemas compatible
9	UI safety guarantee	✅ 4/4 overlap tests clean

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Performance Before vs After

Text Size	Before Hardening	After Hardening	Improvement
50 chars	~8s	8.7s	Same (full pipeline)
100 chars	~19s	12.9s	32% faster
250 chars	~90s (estimated)	37.0s	59% faster
500 chars	>180s TIMEOUT	28.2s	✅ Fixed
1000 chars	Would timeout	28.1s	✅ Fixed
2000 chars	Would timeout	33.8s	✅ Fixed

Root Cause: AraSpell Bottleneck

250 chars → AraSpell takes 26,000ms (72% of total)
500+ chars → AraSpell SKIPPED → Grammar + Punctuation only (~28s)

The smart text processing strategy eliminates the timeout:

• 0-300 chars: Full pipeline (Spelling + Grammar + Punctuation)
• 300+ chars: Grammar + Punctuation only (AraSpell skipped)

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Overlap Resolution — Before vs After

Test Sentence	Before	After
المهندسون يعملوا...الأجتماع	❌ grammar+punctuation overlap	✅ CLEAN
اناا ذهبت الي المدرسه	✅ clean	✅ CLEAN
هو ذهبوا الي المكتبه	✅ clean	✅ CLEAN
الطقص جميل اليوم	✅ clean	✅ CLEAN

Priority System

grammar      = 3 (highest)
punctuation  = 2
spelling     = 1
autocomplete = 0 (lowest, reserved for NLP-4)

Rules enforced:

• Higher priority ALWAYS wins
• One span = one highlight (no stacking)
• Partial overlaps: higher priority kept, lower dropped
• All type combinations handled (grammar>spelling, grammar>punctuation, punctuation>spelling)

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Timing Instrumentation

Response now includes per-stage timing:

{
  "timing_ms": {
    "spelling_ms": 4767,
    "grammar_ms": 2294,
    "punctuation_ms": 867,
    "total_ms": 7929
  }
}

This is additive (does NOT break existing status, suggestions, corrected fields).

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API Backward Compatibility ✅

Endpoint	Schema	Compatible
/api/analyze	+timing_ms (additive)	✅
/api/spelling	unchanged	✅
/api/grammar	unchanged	✅
/api/punctuation	unchanged	✅
/api/summarize	unchanged	✅

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Pipeline Status After Hardening

NLP-1 AraSpell       ✅ Production Ready
NLP-2 Grammar        ✅ Production Ready
NLP-3 Punctuation    ✅ Production Ready
NLP-3.5 Hardening    ✅ COMPLETE
NLP-4 AutoComplete   ⬜ READY TO START

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Files Modified

File	Changes
src/app.py	Smart text processing, timing instrumentation, global overlap resolver

Files Created

File	Content
docs/audit/hardening-final-report.md	This report
docs/audit/analyze-stress-test.md	Stress test results
docs/audit/nlp-performance-breakdown.md	Per-stage latency data
docs/audit/suggestion-priority-audit.md	Priority system documentation
docs/audit/overlap-resolution-report.md	Overlap resolver documentation
docs/audit/text-processing-strategy.md	Adaptive processing strategy