Design and Evolution of a Unified Exchange Mall Middleware Platform

In the booming mobile internet era, apps adopt points exchange and lottery mechanisms to improve user acquisition and retention.

To improve reusability and stability, a unified exchange mall middleware was built to provide standardized points redemption and reward mechanisms for upstream services.

Background: Various growth activities (daily sign‑in, star forest, wish ocean, etc.) generated many independent redemption flows, leading to high development cost and inconsistent systems.

Business architecture: The platform is organized into four layers – upper‑level business (applications using the mall), gameplay sediment (templates using the Template pattern), domain models (activity, template, prize, inventory), and downstream dependencies (marketing, product aggregation, payout, etc.).

Gameplay iteration: The overall gameplay overview, RPC call optimization (1.0 using protobuf‑generated client/server code, 2.0 adopting SPI‑like dynamic routing), inventory design (simple daily/total stock to time‑slot stock with Redis and Lua scripts), prize horizontal iteration, anti‑fraud measures (business‑level frequency control, interface rate limiting, black‑list, token), and stability construction (monitoring, alerting, one‑click circuit‑breaker).

Key code snippets:

rest, err := redis.decr(key)
if err {
    // ...
    return err
}
if rest < 0 {
    return limitErr
}

# KEYS[1] = redis key
# ARGV[1] = pre‑computed remaining stock
local _args1 = ARGV[1]
local stock = redis.call('GET', KEYS[1])
if stock < _args1 then
    return -1
else
    local rest = redis.call('DECR', KEYS[1])
    return rest
end
return -1

Anti‑fraud strategy combines business‑level prize frequency limits, interface rate limiting via a flow‑control center, and black‑/gray‑list filtering with token verification for high‑value prizes.

Stability: Monitoring components, Prometheus SDK metrics, alert rules (pre‑warning, in‑process, post‑statistics) and a one‑click stop‑loss switch enable rapid response to anomalies.

Extensions: A visual H5 lottery component, integration with a growth task platform for point acquisition, and a simple points system completing the earn‑spend‑reward loop.

Conclusion: The exchange mall middleware provides a reusable, extensible backbone for various interactive features, reducing development cost, improving maintainability, and ensuring system stability.