FM Dictionary.

An evidence-backed engineering case study of a Flutter application helping the Facilities Management community master 1,847 domain terms — from a zero-latency Hive local core to Cloudflare edge and Firebase boundaries.

FlutterDartHive DBCloudflare WorkersFirebase1,847 Terms

Product Website View on App Store

Editorial cover for FM Dictionary application — Documented engineering snapshot: FM Dictionary v1.1.0 on Flutter for iOS & Android.

1,847

Current terms

Bundled test items

Recorded tests

1.1.0+9

App Store version

System Architecture

Three-Tier Blueprint: Offline Core, Edge Gateway & Cloud Sync

The architecture strictly decouples 3 isolated boundaries. All primary search and learning loops are guaranteed to execute with zero cloud dependencies.

01 /

CLIENT RUNTIME (FLUTTER + DART)

100% OFFLINE CAPABLE

Zero-latency offline search, card reviews, and phonetic evaluation run entirely on device.

Hive Binary Storage

1,847 FM terms and 50 benchmark test items pre-indexed into local binary boxes (< 5ms response).

Spaced Repetition Engine

State machine tracks Leitner review intervals and test history without requiring network roundtrips.

Rule-Based Phonetic Scorer

Evaluates acoustic transcripts against FM phonetic patterns locally to deliver immediate learner feedback.

02 /

EDGE GATEWAY (CLOUDFLARE WORKERS)

AUTHENTICATED PROXY

Shields upstream credentials and caches dictionary pronunciation audio at edge nodes worldwide.

Edge Audio Cache

Term pronunciation audio clips are cached at Cloudflare edge, reducing latency and upstream egress costs.

API Key Shield & Rate Limiting

Client applications never hold external speech API keys; all traffic is authenticated via worker tokens.

Provider Fallback Routing

Gracefully switches speech providers if primary upstream encounters degradation or rate limits.

03 /

PERSISTENCE BOUNDARY (FIREBASE SERVICES)

ASYNC & NON-BLOCKING

Manages user authentication and synchronizes bookmarks without ever blocking the offline experience.

Anonymous & Email Auth

Users start immediately without registration; sessions can be permanently linked at any time.

Firestore Progress Sync

Bookmarks and mastery metrics sync lazily when a network connection is verified.

Realtime Leaderboard

Lightweight RTDB counters compute cohort study streaks and weekly motivation statistics.

Offline-First Data Flow Schematic

VERIFIED ARCHITECTURE ARTIFACT

Offline data flow schematic for FM Dictionary

Audited Codebase Areas

Engineering Highlights in the Codebase

Local-First Learning Core

HIVE · CODE VERIFIED

Complete bilingual dictionary and 50 benchmark test items are stored in binary Hive boxes. Search, quizzes, and streak calculations execute with zero network overhead.

Safe Dictionary Update Pipeline

ATOMIC · TEST VERIFIED

Remote dictionary updates validate schema version, stage a temporary rollback box, and atomically apply changes with instant fallback if verification fails.

Strict Architectural Boundaries

ZERO-DEPENDENCY CORE

Local Hive operations, Cloudflare proxy edge, and Firebase cloud sync are strictly decoupled. Failure of cloud services never degrades core dictionary functionality.

Hybrid Pronunciation Scoring

EDGE PROXY + LOCAL SCORER

Speech audio is routed through an authenticated edge proxy to obtain phonetic transcripts, which are then scored locally against FM pronunciation rubrics.

Verified Git History

Git History Without the Marketing Leap

2026-03-22

Git 6cd2c76

First meaningful development

Flashcards, Hive persistence and text-to-speech established the first zero-dependency offline learning loop.

2026-05-19

Git a6b69ed

Speech architecture boundary

Local Whisper plan transitioned to authenticated Cloudflare proxy boundaries for lower device memory footprint.

2026-05-31

Git tag v1.0.0

Production release milestone

The repository recorded its first explicit application release tag with bundled 1,847 facilities management terms.

2026-06-05

Git tag v1.1.0

Social learning & telemetry update

Global group leaderboard, progress sync, and accessibility UI refinements were validated and published.

2026-09-06

Phase 2 baseline f59332b

Architecture canonicalization

All storage boundaries, speech fallback mechanisms, and test invariants were audited and documented.

Truthful Engineering Claims

Precision is Part of the Feature

Safe to Claim

Production Flutter mobile application specialized in Facilities Management vocabulary (1,847 terms).
Zero-dependency local-first core: complete lookup and quiz flows operate seamlessly without internet.
Decoupled security boundary: speech APIs and analytics are routed through Cloudflare edge workers without client-side secrets.
Verified testing suite: 27 recorded unit/widget tests and 50 bundled benchmark test scenarios.

Do Not Over-Claim

Claims of fully distributed serverless database: Firebase is utilized solely for non-critical telemetry and sync.
Claims of real-time multi-speaker conversation: speech integration focuses on focused pronunciation assessment.
Claims of third-party user data monetization: zero tracking or commercial telemetry in codebase.

FM Dictionary

Experience the Production Application

fm-dictionary.pages.dev