SkillQuest Production Readiness - Enterprise Error Monitoring & Critical Fixes

Overview

This week focused on production readiness for SkillQuest. We implemented enterprise-grade error monitoring, resolved critical database synchronization issues, and deployed multiple production-ready fixes.

Period: October 15-22, 2025 Commits: 19 Status: Production Ready 🚀

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🐛 Sentry Error Monitoring Integration

Enterprise-Grade Crash Reporting

We integrated Sentry for real-time error tracking and crash reporting in production.

Key Features:

• Automatic Crash Capture: All Flutter errors and native crashes are automatically reported
• Breadcrumbs: Timeline of user actions before crashes for debugging context
• Frame Tracking: Performance monitoring for UI frames (60 FPS target)
• Environment Detection: Automatic detection of development vs production environments
• Debug/Release Filtering: Sentry only active in release builds to avoid development noise

Implementation:

await SentryFlutter.init(
  (options) {
    options.dsn = sentryDsn;
    options.environment = environment;
    options.tracesSampleRate = 0.1; // 10% performance profiling
    options.beforeSend = (event, hint) {
      // Filter debug builds
      if (kDebugMode) return null;
      return event;
    };
  },
  appRunner: () async {
    await _runApp();
  },
);

Binding Fix: Fixed "FramesTrackingIntegration disabled" warning through correct initialization order:

• Sentry init BEFORE WidgetsFlutterBinding
• Automatic SentryWidgetsFlutterBinding.ensureInitialized() call

Impact:

• ✅ Real-time crash reports in production
• ✅ Performance metrics for UI responsiveness
• ✅ User context for debugging (device, OS, app version)

---

🔐 Supabase API Key Migration

Breaking Change: Publishable Keys Required

Supabase disabled legacy JWT API keys. We migrated to the new publishable key format.

Problem:

PostgrestException: Legacy API keys are disabled, code: 401

Solution:

• Old format: JWT-based API keys (deprecated)
• New format: Publishable anon keys with sb_publishable_ prefix

Files Modified:

1. .env - Development credentials
2. .vscode/launch.json - All 6 debug configurations
3. .vscode/launch.json.example - Template with documentation
4. scripts/run_dev.bat - Environment variable parsing for Windows

Windows Batch Script Fix:

REM Old code broke on special characters in SENTRY_DSN
for /f "usebackq tokens=1,2 delims==" %%a in (".env") do (
    set "%%a=%%b"
)

REM New code preserves everything after first =
for /f "usebackq tokens=1* delims==" %%a in (".env") do (
    if not "%%a"=="" (
        set "%%a=%%b"
    )
)

Why this matters:

• ❌ Old approach: Breaks on special characters (/, @, .)
• ✅ New approach: Handles complex values correctly

Impact:

• ✅ App fully operational with new API key format
• ✅ Development workflow (F5 debugging) works correctly
• ✅ Batch script more robust for complex environment variables

---

📊 Active Days System Migration

From Streaks to Active Days

Transition from the old streak system to a new Active Days system with better user retention.

Database Migration:

• New user_active_days table with daily tracking
• 4 level-based milestones: 3, 7, 14, 30 days
• Automatic backfill of existing users
• Total: 3 active users migrated

Schema:

CREATE TABLE user_active_days (
  user_id UUID PRIMARY KEY,
  current_active_days INTEGER DEFAULT 0,
  best_active_days INTEGER DEFAULT 0,
  last_active_date DATE,
  active_days_milestones INTEGER[] DEFAULT '{}'::INTEGER[]
);

Milestone Logic:

• Level 1: 3 days active
• Level 2: 7 days active
• Level 3: 14 days active
• Level 4: 30 days active

Impact:

• ✅ Better retention tracking
• ✅ Progressive milestone system
• ✅ Backward compatible with existing data

---

⏱️ Timer System Fixes

Race Condition & XP Level Sync

Multiple critical fixes for timer completion and XP synchronization.

Fix 1: Timer Completion Race Condition

Problem: UI tried to display XP before database update was complete, resulting in outdated XP values.

Solution:

// BEFORE: Parallel database updates + UI update
Future.wait([
  _updateUserXp(),
  _updateSkillXp(),
  _recordSession(),
]);
ref.invalidate(providers); // ❌ Too early!

// AFTER: Sequential database updates → UI update
await _updateUserXp();
await _updateSkillXp();
await _recordSession();
ref.invalidate(providers); // ✅ After all DB updates

Impact:

• ✅ Correct XP display after timer completion
• ✅ No race conditions between DB and UI

Fix 2: XP Level Calculation Consistency

Problem: Database trigger used wrong formula (FLOOR(SQRT(xp / 100.0))), Flutter used exponential progression.

Result: "Level correction" debug messages on every app load.

Database Formula Fix:

CREATE OR REPLACE FUNCTION calculate_level_from_xp(xp_amount INTEGER)
RETURNS INTEGER AS $$
DECLARE
  current_level INTEGER := 1;
  accumulated_xp INTEGER := 0;
  xp_for_next INTEGER;
BEGIN
  -- Exponential progression matching Flutter
  -- XP needed: 150 * pow(1.0565, level - 1)
  WHILE current_level < 100 LOOP
    xp_for_next := ROUND(150.0 * POWER(1.0565, current_level - 1));

    IF accumulated_xp + xp_for_next <= xp_amount THEN
      accumulated_xp := accumulated_xp + xp_for_next;
      current_level := current_level + 1;
    ELSE
      EXIT;
    END IF;
  END LOOP;

  RETURN current_level;
END;
$$ LANGUAGE plpgsql IMMUTABLE;

Test Coverage:

• 9 Flutter tests covering critical XP thresholds
• Database assertions verifying formula correctness
• Boundary tests for exact level-up points

Impact:

• ✅ Perfect sync between PostgreSQL and Flutter
• ✅ No more level corrections
• ✅ Performance boost from IMMUTABLE function

---

🌍 Internationalization (i18n) Enhancements

Stats Display with Full Localization

Complete i18n support for statistics charts with timezone-aware data.

Period Format Localization:

Timezone Support:

String _getUserTimezone() {
  final location = tz.local;  // Device timezone
  return location.name;        // IANA identifier
}

// Pass to SQL function
'p_timezone': userTimezone,  // e.g., 'Europe/Amsterdam'

Impact:

• ✅ Month names and weekdays follow app language (NL/EN)
• ✅ Language switch works without app restart
• ✅ Timezone-aware statistics worldwide
• ✅ Hot reload support for i18n changes

---

🔒 Database Security Hardening

PostgreSQL Function Security

Added search_path hardening for all database functions to protect against SQL injection.

Before:

CREATE FUNCTION calculate_level_from_xp(xp_amount INTEGER)
RETURNS INTEGER
LANGUAGE plpgsql
IMMUTABLE
AS $function$
-- Vulnerable to search_path manipulation

After:

CREATE FUNCTION calculate_level_from_xp(xp_amount INTEGER)
RETURNS INTEGER
LANGUAGE plpgsql
IMMUTABLE
SET search_path TO 'public', 'pg_temp'  -- ✅ Hardened
AS $function$

Security Benefits:

• ✅ Prevents malicious schema hijacking
• ✅ Enterprise-grade function isolation
• ✅ Complies with PostgreSQL security best practices

---

📈 Production Metrics

Current Status

Code Quality:

• ✅ Flutter analyze: 0 errors
• ✅ All tests passing
• ✅ Clean git history with atomic commits

Database:

• ✅ Zero security issues (Supabase Security Advisor)
• ✅ 100% RLS coverage
• ✅ Performance optimized with proper indexing

Monitoring:

• ✅ Sentry error tracking enabled
• ✅ Frame tracking for performance monitoring
• ✅ Breadcrumbs for debugging context

Deployment:

• ✅ Environment variables fully configured
• ✅ API keys migrated to publishable format
• ✅ Development workflow (F5 debugging) functional

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🎯 Key Takeaways

1. Enterprise Monitoring: Sentry integration provides real-time crash reports and performance metrics in production
2. API Migration: Proactive migration to Supabase publishable keys prevents breaking changes
3. Database Consistency: XP level formula sync between PostgreSQL and Flutter eliminates data discrepancies
4. International Ready: Full i18n support with timezone-aware statistics for worldwide users
5. Security First: PostgreSQL function hardening meets enterprise security standards

Status: SkillQuest is production-ready with robust error monitoring, consistent data synchronization, and enterprise-grade security 🚀