Third-party dependencies

External APIs bring their latency, limits and outages into your system. Isolate them with timeouts, circuit breakers and queues, cache their answers where possible, and decide what your product does when they are down.

Where it shows up in real systems

  • Payment provider

    Calls take hundreds of milliseconds, a small share fails transiently, and the provider rate-limits you. Never charge twice: send an idempotency key with each request, retry with backoff, and move the call out of the user request path when you can.

    In production: Stripe, Adyen, PayPal, Moneris, Square

  • Email and SMS provider

    Delivery is slow and can fail, so send from background workers, never while the user waits. Providers throttle senders and track bounces; a burst of password-reset emails can hit the limit.

    In production: Amazon SES, SendGrid, Mailgun, Twilio, Postmark

  • Third-party API

    Its latency, rate limits and outages become yours. Cache what you can, set short timeouts, wrap it in a circuit breaker and design a degraded mode for when it is down.

    In production: Google Maps Platform, OpenWeather, Shippo, Anthropic API, OpenAI API

See it break, then fix it

Build an architecture, send it a day of traffic and outages, and learn why it holds or fails. Free to start.

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