Retail & E-commerce / Entertainment Web
ShopCast — the watch-and-buy live-commerce platform

Streaming, chat, cart, and payments — Unified into one live experience. Watch and buy on the spot.

Retail Live Inc. — Live-stream shopping built in-house from scratch, end-to-end across low-latency concurrent streaming, real-time chat, a live cart, and instant payments.

10,000+
A streaming platform that supports concurrent viewing
Supports large-scale live streaming
Under 1 second
Streaming & chat latency
Real-time two-way
Several×
Viewing → purchase conversion
The “watch and buy” experience
Challenge
Design challenge

When live streaming and e-commerce checkout are disconnected, viewers can’t buy the moment they think “I want it” and drop off. How to handle the live-specific load of concurrent viewing and buying became the design challenge that would make or break both experience and revenue.

  • We want to offer a buy-while-watching experience
    Gap between viewing and buying / drop-off
  • Keep chat uninterrupted even under massive concurrent viewing
    Peak-time real-time load
  • We want accurate inventory and cart updates during live
    Concurrent-purchase contention / inventory consistency
  • We want to process diverse payments safely and instantly
    Stripe / GMO instant payments
Solution
After build

Low-latency live streaming, real-time chat, a live cart, and instant payments unified on one platform. A watch-and-buy experience for viewers, stable concurrent streaming for hosts, and a scalable real-time platform for operations — optimizing all three at once.

Streaming → viewing → chat → cart → instant payment, end to end Host Host & sell Live stream Live stream Agora RTC Low latency Viewer 10k concurrent Mobile view Chat NestJS WS Real time Cart Stock sync Add fast Instant pay Stripe GMO Buy on the spot while watching A scalable real-time live-commerce platform Low-latency stream Agora RTC NestJS WS + Redis Sync chat & cart Instant buy Stripe / GMO Handling two-way traffic for 10,000 concurrent viewers with Redis Pub/Sub
live.shopcast.example.jp
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Live shopping screen — streaming, chat, product cart, and instant purchase unified on one screen
Tech stack React Agora RTC NestJS WebSocket Laravel Stripe / GMO
12 months
110 person-months
Considering adopting this at your company? → info@amela.vn