<p>I'm testing Seldon Core and am wondering if there is an easy way to route the output of model A as the input of model B on Seldon Core. 
What would be the best practice? </p>

<p>In a SeldonDeployment resource definition you have a graph section. The top-level element is the first step and it contains children for a next step. Here is a snippet <a href="https://github.com/SeldonIO/seldon-core/issues/772" rel="nofollow noreferrer">from an example</a> showing a transformer being used to transform a request before passing it on to a model:</p>

<pre><code>    graph:
      children:
        - children: []
          implementation: XGBOOST_SERVER
          name: model
          modelUri: s3://model-image
          type: MODEL
      endpoint:
        type: REST
      name: feature-transformer
      type: TRANSFORMER
</code></pre>

<p>There's an <a href="https://docs.seldon.io/projects/seldon-core/en/latest/examples/kubeflow_seldon_e2e_pipeline.html#Breaking-down-the-code" rel="nofollow noreferrer">example in the seldon documentation</a> where steps such as clean and tokenize are used to perform inference for natural language processing. That example has multiple steps as type MODEL. There's also <a href="https://seldondev.slack.com/archives/C8Y9A8G0Y/p1560761929110900?thread_ts=1560423848.095200&amp;cid=C8Y9A8G0Y" rel="nofollow noreferrer">discussion on this in the seldon slack channel</a>.</p>
