Klaviyo is an ecommerce marketing automation platform that lets organizations run data-driven email and Facebook campaigns.

Snowflake is a cloud-based data warehouse implemented as a managed service. It runs on the Amazon Web Services architecture, and separates compute and storage resources, enabling users to scale the two independently and pay only for resources used. It can provide access to the same data for multiple workgroups or workloads simultaneously with no contention roadblocks or performance degradation.

Klaviyo exposes data through several REST APIs, which developers can use to extract information on metrics, profiles, lists, campaigns, and templates. Each of these APIs has two to seven optional parameters you can use to refine the information returned. As an example, a simple call to retrieve data via the Klaviyo Metrics API would look like:

GET https://a.klaviyo.com/api/v1/metrics

The GET call returns a JSON object with all the fields of the specified dataset as a reply. All fields may not be present for any given record. The JSON might look like:

{
  "end": 1,
  "object": "$list",
  "page_size": 50,
  "start": 0,
  "total": 2,
  "data": [
    {
      "updated": "2017-11-03 17:28:09",
      "name": "Active on Site",
      "created": "2017-11-03 17:28:09",
      "object": "metric",
      "id": "3vtCwa",
      "integration": {
        "category": "API",
        "object": "integration",
        "id": "4qYGmQ",
        "name": "API"
      }
    },
    {
      "updated": "2017-11-03 20:54:40",
      "name": "Added integration",
      "created": "2017-11-03 20:54:40",
      "object": "metric",
      "id": "8qYK7L",
      "integration": {
        "category": "API",
        "object": "integration",
        "id": "4qYGmQ",
        "name": "API"
      }
    ]
  }

You may need to prepare your data before loading it. Check Snowflake's supported data types and make sure that your data maps neatly to them.

Note that you won't need to define a schema in advance when loading JSON or XML data into Snowflake.

Turn to Snowflake's Data Loading Overview for help with the task of loading your data. If you're not loading a lot of data, you might be able to use Snowflake's data loading wizard, but its limitations make it unsuitable as a reliable ETL solution for some use cases. As an alternative, you can:

• Use the PUT command to stage files.
• Use the COPY INTO table command to load prepared data into an awaiting table.

You’ll have the option of copying from your local drive or from Amazon S3 – and Snowflake lets you make a virtual warehouse to power the insertion process.

At this point you've coded up a script or written a program to get the data you want and successfully moved it into your data warehouse. But how will you load new or updated data? It's not a good idea to replicate all of your data each time you have updated records. That process would be painfully slow and resource-intensive.

Instead, identify key fields that your script can use to bookmark its progression through the data and use to pick up where it left off as it looks for updated data. Auto-incrementing fields such as updated_at or created_at work best for this. When you've built in this functionality, you can set up your script as a cron job or continuous loop to get new data as it appears in Klaviyo.

And remember, as with any code, once you write it, you have to maintain it. If Klaviyo modifies its API, or the API sends a field with a datatype your code doesn't recognize, you may have to modify the script. If your users want slightly different information, you definitely will have to.

Snowflake is great, but sometimes you need to optimize for different things when you're choosing a data warehouse. Some folks choose to go with Amazon Redshift, Google BigQuery, PostgreSQL, or Microsoft Azure Synapse Analytics, which are RDBMSes that use similar SQL syntax, or Panoply, which works with Redshift instances. Others choose a data lake, like Amazon S3 or Delta Lake on Databricks. If you're interested in seeing the relevant steps for loading data into one of these platforms, check out To Redshift, To BigQuery, To Postgres, To Panoply, To Azure Synapse Analytics, To S3, and To Delta Lake.