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Research files synthesized: - STACK.md: Flutter + Supabase + Riverpod recommended stack - FEATURES.md: 7 table stakes, 6 differentiators, 7 anti-features identified - ARCHITECTURE.md: Offline-first sync with optimistic locking, RLS multi-tenancy - PITFALLS.md: 5 critical pitfalls (v1), 8 moderate (v1.5), 3 minor (v2+) - SUMMARY.md: Executive synthesis with 3-phase roadmap implications Key findings: - Stack: Flutter + Supabase free tier + mobile_scanner + Open Food Facts - Critical pitfalls: Barcode mismatches, timezone bugs, sync conflicts, setup complexity, notification fatigue - Phase structure: MVP (core) → expansion (usage tracking) → differentiation (prediction + sales) - All research grounded in ecosystem analysis (12+ competitors), official documentation, and production incidents Confidence: HIGH Ready for roadmap creation: YES Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
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Pitfalls Quick Reference Table
Quick lookup for all 13 pitfalls with severity, prevention, and phase mapping.
Critical Pitfalls (v1 Must Address)
| # | Pitfall | Severity | Root Cause | Prevention | Phase | Detection |
|---|---|---|---|---|---|---|
| 1 | Barcode Mismatches & Duplicates | CRITICAL | No fuzzy matching, no dedup | Canonical names + local dedup + fuzzy matching | v1 | Users report duplicate items (3x "Milk") |
| 2 | Timezone & Expiration Bugs | CRITICAL | Dates stored without UTC | Store all dates as UTC ISO 8601 | v1 | Item shows expired in one zone, fresh in another |
| 3 | Multi-User Sync Conflicts | CRITICAL | Last-Write-Wins naive strategy | Optimistic locking + version numbers | v1 | Concurrent updates silently lost; "I added it but it's gone" |
| 4 | Setup Complexity | CRITICAL | 15 required fields in MVP | 3-field MVP (name, location, expiry) | v1 | 50%+ onboarding dropout; "too complicated" reviews |
| 5 | Notification Fatigue | CRITICAL | Simple "if expires in N days, notify" | Snooze button + configurable timing | v1 | Users disable notifications entirely |
Moderate Pitfalls (v1.5 Required)
| # | Pitfall | Severity | Root Cause | Prevention | Phase | Detection |
|---|---|---|---|---|---|---|
| 6 | Offline Sync Data Loss | HIGH | Queue not persisted to disk | Persist queue locally + operation IDs | v1.5 | "I added items while offline and they disappeared" |
| 7 | Barcode Scanner Failures | HIGH | Low-quality scanner lib, no fallback | Robust lib (ML Kit/AVFoundation) + fallback + correction UI | v1.5 | "Scanned item is completely wrong"; low barcode feature usage |
| 8 | Search/Item Lookup UX | HIGH | Case-sensitive exact matching; no fuzzy | Full-text search + fuzzy matching + stemming | v1.5 | Users can't find items; high duplicate rate |
| 9 | Insufficient Permissions | HIGH | Binary permissions; no audit log | Clear role model + audit logging + ownership | v1.5 | Multi-user distrust; "who deleted my item?" |
| 10 | Performance & Battery Drain | MEDIUM | No indexing; syncs too frequently | Aggressive indexing + optimized syncing | v1.5 | Search >1s; app drains 10%+ battery/hour |
Minor Pitfalls (v2 Deferred)
| # | Pitfall | Severity | Root Cause | Prevention | Phase | Detection |
|---|---|---|---|---|---|---|
| 11 | API Cost Surprises | MEDIUM | Paid APIs without fallback | Use free APIs only in v1; plan fallback strategy | v2 | Bill grows faster than user base |
| 12 | AI Prediction Overfitting | LOW | Small sample size per user | Start simple; add ML only after 500+ items/user | v2 | Users turn off predictions; feature unused |
| 13 | Community Spam & Privacy | LOW | No moderation; data validation missing | Don't build community features in v1 | v2 | Spam in community data; privacy concerns |
Phase Implementation Order
v1 MVP (6-8 weeks)
Non-negotiable: Pitfalls 1, 2, 3, 4, 5
- Without barcode dedup, users lose trust
- Without UTC, timezone bugs kill reliability
- Without sync conflict handling, multi-user is broken
- Without simple onboarding, 50% abandon before first item
- Without notification control, users disable it and feature dies
v1.5 Stabilization (4-6 weeks)
Required for adoption: Pitfalls 6, 7, 8, 9, 10
- Offline sync prevents data loss (trust issue)
- Barcode error handling prevents user frustration
- Better search prevents duplicate creation
- Permissions prevent multi-user conflicts
- Performance optimization keeps users engaged
v2 Growth Phase (3-6 months)
Only after v1 stable: Pitfalls 11, 12, 13
- Community features need moderation (cost/effort)
- ML predictions need enough user data (not viable in v1)
- Cost surprises manageable after finding product-market fit
Prevention Checklist for v1
Use this before launching MVP:
- Barcode: Implemented fuzzy matching on product names
- Barcode: Deduplication detects and merges duplicates
- Barcode: Uses USDA FoodData Central or Open Food Facts
- Timezone: All dates stored as UTC ISO 8601 (not just DATE type)
- Timezone: Tested expiration logic across 3+ timezones
- Sync: Implemented optimistic locking with version numbers
- Sync: Every operation has unique operation ID (idempotency)
- Sync: Concurrent edits tested and don't lose data
- Onboarding: First item requires only 3 fields (name, location, expiry)
- Onboarding: Measured and <20% onboarding dropout
- Notifications: Alert snooze button implemented
- Notifications: Alert timing configurable (default 3 days before expiry)
- Notifications: Dismissed alerts don't re-trigger for 24h minimum
Detection Checklist (Weekly During Development)
Run this every sprint to catch pitfalls early:
- No user reports of "same item appears twice"
- Expiration tests pass across UTC, EST, PST, IST
- Concurrent update tests don't lose data
- 80%+ of users complete onboarding (add first item)
- 0 crashes during bulk operations
- Barcode scan fallback (manual entry) works
- Notification spam reports = 0
- Search latency <500ms on 100 items
Implementation Priority Matrix
Use this to sequence feature work:
| Pitfall | Effort | Impact | Block Other Work? | Implement When |
|---|---|---|---|---|
| Barcode dedup | Medium | Critical | Yes (data integrity) | Week 1 |
| UTC timestamps | Low | Critical | Yes (all date logic) | Week 1 |
| Optimistic locking | Medium | Critical | Yes (sync) | Week 2 |
| 3-field onboarding | Low | Critical | Yes (adoption) | Week 2 |
| Notification snooze | Low | Critical | Yes (retention) | Week 3 |
| Offline sync | Medium | High | No (can fallback) | v1.5 |
| Barcode errors | Medium | High | No (manual entry fallback) | v1.5 |
| Advanced search | Medium | High | No (basic search OK) | v1.5 |
| Permissions | Medium | High | No (owner-only OK) | v1.5 |
| Performance | Low | Medium | No (can optimize later) | v1.5 |
| API costs | Low | Medium | No (free tier OK) | v2 |
| ML predictions | High | Low | No (defer) | v2 |
| Community | High | Low | No (defer) | v2 |
Real-World Reference
Apps That Failed at These Pitfalls
My Pantry Tracker:
- Pitfall #2 (expiration date glitch preventing visibility)
- Pitfall #8 (search/categorization issues)
FoodShiner:
- Pitfall #7 (barcode scanner fails in split-view)
- Pitfall #7 (wrong product on scan)
NoWaste:
- Pitfall #4 (crashes during bulk operations - too many features)
- Pitfall #6 (data loss during crashes)
Pantry Check:
- Pitfall #4 (too many options, confusing export)
CozZo:
- Pitfall #6 (no offline fallback; app shut down when cloud shutdown)
Sources
All prevention strategies backed by:
- 40+ researched sources
- 10+ app store reviews with specific complaints
- Real-world case studies (Sylius, Atlassian, GitHub)
- Distributed systems best practices
- User adoption research
See PITFALLS.md for full citations.