How a crypto screener works: WebSocket, filters, signals

A crypto screener is not just a bot with buttons - it is a data pipeline. First the stream, then rules, then delivery to the user. If you reverse that order, the product quickly turns into spam alerts and socket crashes.

Core blocks

• WebSocket/REST collectors from Binance, Bybit, OKX, BingX and other exchanges
• Metric normalization: price, OI, funding, liquidations, volume
• User filters and trigger thresholds
• Queue/dedup so identical alerts do not spam users
• Telegram bot or web dashboard as the delivery channel

In practice it helps to split data collection and the user layer. Then you can fix an exchange without stopping the bot, and the other way around.

Where it usually breaks

Unstable sockets, API limits, different exchange formats, user growth without rate control. From day one you need retries, logs and the ability to disable an exchange without killing the whole service.

Another risk is noisy signals. Without dedup and sane thresholds users unsubscribe faster than you can add a new metric.

What to design early

Subscriptions, admin, trial, i18n and process monitoring. Otherwise the product hits manual support and chaotic fixes within a month. A good screener sells on reliable delivery of useful events - not on a pretty menu.