Snagly Case Study

Case Study

Real-Time Mobile Marketplace & Live Selling Platform

A cross-platform mobile marketplace (React Native + Expo) backed by NestJS and Supabase. Features real-time live auction bidding, interactive video live-stream selling, offer negotiations, and 7-language RTL support.

Visit Live Site

2026

Year

Mobile & Backend Architecture

Services

React Native + NestJS + Socket.IO

Tech Stack

Mobile & Real-Time Commerce

Executive Summary

Snagly is an end-to-end peer-to-peer mobile marketplace built to modernize second-hand and new goods trading. Combining classic classifieds with live-stream video commerce, real-time auction bidding, and instant chat negotiations, Snagly provides sellers with high-engagement sales channels and buyers with interactive, trusted shopping experiences.

Supported Languages (RTL-ready)

<50ms

Real-Time Bid Latency

60fps

Native UI Performance

100%

Offline Mock Mode Coverage

0.8s

Initial Video Stream Connect

Core Navigation Stacks

The Challenge

Modern marketplace apps must balance high-frequency real-time features—such as live video streams and sub-second auction bidding—with smooth mobile performance across diverse devices and varying network conditions.

Key Problems Identified:

•
Multi-Surface Real-Time State: Synchronizing auction countdown timers, live bids, chat messages, and video stream pinned items across thousands of mobile clients without state corruption.
•
Global Accessibility & RTL Layouts: Supporting 7 languages (including right-to-left Arabic layouts) seamlessly across every component, modal, and custom navigation tab.
•
Dual-Engine Architecture: Providing an instant client-side mock engine for seamless offline demoing alongside a resilient NestJS + Supabase backend for live production users.
•
Complex Commerce Flows: Managing multi-step buyer-seller state transitions: from offer submission, seller approval, and bidding to localized checkout and shipping label generation.

Mission Statement:

Engineered an interactive, real-time mobile marketplace that combines live-stream commerce, auction bidding, and multi-language support into a unified, high-performance experience.

The platform required a modular React Native architecture paired with event-driven WebSockets and a scalable PostgreSQL data store.

Solution

Snagly leverages Expo SDK 57 and React Native for a cross-platform mobile frontend, powered by Socket.IO for real-time events and NestJS + Supabase for production data management.

Live-Stream Commerce

Interactive video rooms allowing sellers to highlight pinned products live while buyers chat and purchase in real time.

Sub-Second Auctions

WebSocket-driven live bidding rooms with countdown timers, dynamic price updates, and instant outbid alerts.

7 Languages & RTL

Built-in i18n support with complete Right-to-Left layout adaptation for Arabic users.

Our Approach Focused on Three Core Pillars:

1. Real-Time Commerce Engine

• Socket.IO rooms for live auction bids and video stream interaction
• Pinned item callouts during live video sessions
• In-app buyer-seller chat with push notifications

2. Scalable Mobile Architecture

• Expo Dev Client with custom native plugins for video and audio
• Redux Toolkit & RTK Query for predictable state & caching
• Auto-hiding floating pill tab navigation for maximum screen space

3. Robust Backend & Mock Layer

• NestJS API backed by Supabase PostgreSQL database
• Fallback mock API engine for instant demo and guest exploration
• Multi-currency, localized payment and shipping integrations

Target Audience:

Primary: Peer-to-peer buyers and sellers looking for interactive marketplace features

Secondary: Live-stream creators and boutique merchants selling items live

Tertiary: Global users seeking multi-language localized trading communities

Technical Architecture

Mobile App Stack

✓React Native 0.86 & Expo SDK 57
✓TypeScript (Full type safety)
✓Redux Toolkit & RTK Query
✓React Navigation (Native Stack)
✓i18next (7 languages with RTL support)

Real-Time & Backend

✓NestJS (Node.js framework)
✓Socket.IO (Bid & live-stream signaling)
✓Supabase / PostgreSQL database
✓Docker containerized backend

Web & Admin Ecosystem

✓Next.js 16 (Landing page & Web platform)
✓Tailwind CSS v4 & GSAP animations
✓Vercel production deployment

Key Features & Innovation

Live-Stream Video Selling

Sellers stream live video while broadcasting pinned product cards directly into viewer chats.

• Real-time video chat

• Pinned product CTA

• Viewer interactive reactions

Live Auction Rooms

Competitive bidding rooms featuring sub-second countdown timers and instant bid notifications.

• Real-time bid ticker

• Automatic extension timers

• Outbid push alerts

In-App Negotiation & Chat

Direct buyer-seller messaging with embedded offer submission and counteroffer acceptance.

• Structured offer cards

• Read receipts

• Status tracking

Native Multi-Language & RTL

Fully localized interface supporting English, Arabic, French, Chinese, Spanish, Hindi, and Tagalog.

• Dynamic RTL layout flipping

• Localized currency & date formatting

Performance & Results

60fps

Mobile UI Frame Rate

<50ms

Auction Sync Latency

Languages Fully Localized

100%

Offline Demo Functionality

Snagly demonstrates how real-time interactive video and auction mechanics can be combined cleanly inside a mobile app without compromising on frame rates or response times.

The custom navigation architecture and state management layer keep screen transitions smooth across iOS and Android while supporting instant updates across Socket.IO rooms.

Business Impact & Results

High-Engagement Sales

• Interactive live-stream selling drives higher item conversion

• Sub-second auction rooms encourage competitive bidding

• In-app offer negotiation streamlines transaction closing

Global Scalability

• 7 languages out of the box with native RTL rendering for Arabic

• Cross-platform iOS and Android builds from a single codebase

• Modular backend structure with NestJS and Supabase

By unifying classifieds, live-streaming, and auction bidding, Snagly provides a modern marketplace platform ready for global deployment.

Experience real-time mobile marketplace commerce with live streaming and auctions