Feature 01
Car BlockMobile + Marketplace20258 Months
Car Block — Peer-to-Peer Automotive Marketplace
Peer-to-peer automotive marketplace with AI VIN scanning, escrow-protected payments, and 5+ transaction modes — buy, sell, trade, lease, donate. Services: Mobile App Development, Backend Engineering, Web Dashboard
FlutterDartSupabaseReactFirebaseStripe
Section 01 · Overview
Overview
Car Block is a next-generation peer-to-peer automotive marketplace that redefines how vehicles are bought, sold, traded, leased, and donated across the United States, with a roadmap toward global expansion. Unlike fragmented classifieds where buyers gamble on stranger transactions, Car Block bundles AI-powered VIN scanning, Trustap-secured escrow, verified seller reputation, and a unified marketplace covering 5+ transaction modalities in one mobile-first product. Listings are created in seconds by scanning the VIN with the phone camera, payments are held in escrow until ownership transfers, and a complementary React.js admin dashboard gives operators end-to-end visibility into every transaction, dispute, and accessory order.
Feature 02
Trustap-secured escrow holds funds until ownership transfers safely.
Feature 03
5+ transaction modes: buy, sell, trade, lease, donate, accessorize.
Feature 04
Real-time push notifications powered by Firebase Cloud Messaging.
The Challenge · Problem Statement
Problem Statement
The used-car market in the US is fragmented across Craigslist, Facebook Marketplace, OfferUp, dealer networks, and donation portals — each missing something the others have. Buyers face fraud risk with no payment protection, sellers manually type 30+ vehicle fields per listing, dealers extract heavy margins on trade-ins, and there is no single trusted home for buying, selling, trading, leasing, or donating a vehicle in one place.
User Painpoints
Fragmented Marketplaces
Buyers and sellers hop between Craigslist, Facebook, OfferUp, and CarMax just to compare options, doubling effort and tripling fraud exposure.
Zero Payment Protection
Most P2P platforms hand off the deal once messages exchange, leaving buyers vulnerable to wire scams and sellers chasing bounced cashier's checks.
Tedious Listing Creation
Manually entering VIN, make, model, year, trim, mileage, and 20+ specs deters casual sellers and produces listings riddled with errors.
No Multi-Modal Flexibility
Selling, trading, leasing, and donating each require different platforms today — there is no single app where users can pivot between modes.
How We Build · Design Process
Design Process
Our proven 4-step approach to delivering products that actually ship.
- Step 01
Discover
User research, stakeholder interviews, and competitive analysis to ground every decision in evidence.
- Step 02
Define
Product hypothesis, user stories, and a prioritized scope we can all sign off on before a pixel is drawn.
- Step 03
Design
Style guide, high-fidelity wireframes, and clickable prototypes validated with real target users.
- Step 04
Deliver
Production-grade UI, component libraries, and a fully documented system your engineers can ship fast.
Section 04 · Our Solution
Our Solution
How we solved each pain point — with outcomes, not ambiguity.
- Flagship Solution · 01
Unified P2P Marketplace
One mobile app for buying, selling, trading, leasing, donating, and accessorizing — eliminating the cross-platform shuffle.
- Solution 02
Trustap Escrow Layer
Funds are held by Trustap until both parties confirm ownership transfer. Disputes pause the release. Sellers ship with confidence; buyers pay without fear.
- Solution 03
AI VIN Scanner
Google ML Kit reads the VIN from the dashboard or door jamb in one tap and auto-populates make, model, year, trim, and engine details — turning a 10-minute listing into 30 seconds.
- Solution 04
Verified Reputation
Every transaction feeds a community reputation score. High-reputation sellers see their listings boosted; bad actors are throttled or banned.
- Solution 05
Operator Dashboard
A React.js admin console gives the operations team real-time visibility into transactions, disputes, accessory orders, and platform health — keeping the marketplace healthy at scale.
Section 06 · Visual System
Color Palette & Typography
The visual language guiding every pixel.
Color Palette
Carbon Black
#0E0E12
Block Red
#E63946
Steel Blue
#1D4ED8
Neon Lime
#A3E635
Cool White
#F8FAFC
Typography
Typography
Inter
Extra Bold · Bold · Semi Bold · Medium · Regular · Light
Aa Bb Cc · 0 1 2 3 4 5 6 7 8 9
Tech Stack
Technology Stack
The production-grade stack we used to ship this product — and exactly how each piece pulls its weight.
Mobile
How We Use
Single Flutter codebase ships native iOS and Android apps with 60fps scrolling through thousands of listings, photo galleries, and live messaging.
Benefit
Native performance on both platforms with one engineering team — half the build cost and half the maintenance surface area.
Language
How We Use
Strongly-typed, null-safe codebase for the entire mobile app, with hot reload that lets the team iterate on listing screens in real time.
Benefit
Catches an entire class of bugs at compile time, keeping a financial marketplace stable at scale.
Backend
How We Use
Postgres database with row-level security, built-in auth, and storage buckets for vehicle photos. Listings, offers, messages, and disputes all live behind RLS policies that enforce who can see and edit what.
Benefit
Production-grade backend without managing servers — RLS keeps user data isolated by default, exactly what a peer-to-peer marketplace requires.
Database
How We Use
Source of truth for vehicles, listings, offers, escrow records, transactions, and audit trails — all enforced with foreign-key constraints and ACID guarantees.
Benefit
Financial-grade data integrity — every escrow release and ownership transfer is reconcilable down to the cent.
Web Dashboard
How We Use
Powers the operator admin dashboard — transaction monitoring, dispute resolution, accessory inventory, user management, and KPI analytics.
Benefit
Operators get a rich, interactive cockpit on any browser, with reusable components keeping new admin screens cheap to ship.
Notifications
How We Use
Firebase Cloud Messaging delivers instant push notifications for new offers, escrow updates, message replies, and listing engagement across iOS and Android.
Benefit
Keeps buyers and sellers engaged in real time — the difference between a deal that closes today and one that drifts away.
Payments
How We Use
Payment intents and connected accounts move funds into Trustap escrow and release them on transfer confirmation — all PCI-compliant out of the box.
Benefit
Battle-tested payment rails handle cards, ACH, and dispute flows so the team can focus on the marketplace, not on PCI audits.
AI / ML
How We Use
On-device OCR scans the VIN from the dashboard or door jamb in one camera tap, auto-populating make, model, year, trim, and engine specs.
Benefit
A 10-minute listing chore turns into 30 seconds — the single biggest unlock for casual sellers entering the marketplace.
Outcomes · Results & Impact
Results & Impact
What Car Block shipped — and what it delivered.
0+
Transaction Modes Supported
0s
VIN-to-Live-Listing Time
0%
Escrow-Protected Payments
iOS + Android
Live in Both App Stores
