# Lambda

{% stepper %}
{% step %}
Member makes a transaction using a mobile app
{% endstep %}

{% step %}
Transaction details are sent to API Gateway so that it calls two serverless functions:

* First Lambda function registers a transaction in the Order Management system
* Second Lambda function registers a transaction in Open Loyalty
  {% endstep %}

{% step %}
As a result, Open Loyalty sends a webhook to the third Lambda function that a Member earned points 
{% endstep %}

{% step %}
The third Lambda function calls Marketing Auto’s API to send Member a push notification about earned points / received reward
{% endstep %}
{% endstepper %}

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