Drupal is a great platform, but it can’t do everything. As your site grows, you’ll likely encounter use cases that Drupal can’t or shouldn’t do. Some examples include interacting with third-party APIs while preserving good page loads, or performing repeated actions (polling, etc) that result in site updates. Fortunately, separating these kinds of problems from Drupal and moving them to specialized “sub-stacks” within or near your Drupal stack is easy to do.
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