Extract, Transform, Load (ETL)

ETL is a three‑step data process that helps you turn raw inputs into trustworthy information you can use. You extract data from multiple sources, transform it by cleaning and structuring it, then load it into a destination such as a data warehouse or lakehouse where your team can access it. Put simply, ETL is how you turn scattered, messy data into something clear and usable.

In depth

ETL sits at the backbone of your data stack. The extract step pulls records from apps, databases, files, and APIs on a schedule or in near real time. The transform step fixes errors, handles missing values, standardizes formats like dates and currencies, joins related tables, and applies business rules so the data reflects how your company works. The load step writes the prepared results to a target system, commonly a warehouse like Snowflake, BigQuery, or Redshift.

Teams use ETL to improve data quality and to comply with controls around privacy and retention. You can run ETL in batches or stream updates as new events arrive. Modern platforms add automation for schema change detection, error handling, and lineage so you can see where numbers come from. Many tools now include AI‑assisted mappings and transformations that speed up common tasks while keeping humans in the loop.

ETL is closely related to ELT. With ELT, you extract and load raw data first, then transform it inside the warehouse using tools like dbt. Both approaches aim for the same goal, which is reliable, well‑modelled data. Your choice depends on scale, latency needs, and the skills on your team.

Pro tip

Draw a clear boundary between transformation for governance and transformation for metrics. Keep source cleaning and business rules in your ETL layer, then express metric logic in your analytics layer. This separation makes audits, ownership, and changes much easier.

Why it matters

  • Trusted numbers. Consistent cleaning and rules mean your revenue, churn, and pipeline metrics match across teams.
  • Faster analysis. Analysts spend less time fixing data and more time answering questions.
  • Compliance and security. Controls for PII handling, retention windows, and access keep you onside with regulations.
  • Scale. Centralized pipelines handle more sources, higher volumes, and growth without constant rework.
  • Team alignment. Shared datasets and definitions reduce reporting conflicts and rebuild trust in dashboards.

ETL - In practice

  • You pull transactions from Stripe, subscriptions from your product database, and campaigns from HubSpot. You standardize customer IDs, convert currencies to USD, and calculate net revenue. You load the modeled tables into Snowflake on an hourly schedule. Your dashboards read from these tables, so everyone sees the same definitions.
  • You stream events from a web app into a queue, apply real‑time transformations for session attribution, then land results in BigQuery within minutes so product managers can watch feature adoption during a rollout.
  • You run ELT instead of classic ETL. Raw data lands first, then dbt models create cleaned, governed tables that business users can query safely.
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Product‑specific notes

PowerMetrics sits on top of your data, not in place of ETL. You can:

  • Connect to where your data lives. Use connectors for apps, files, databases, and warehouses to pull governed datasets that ETL or ELT created.
  • Model light transformations. Combine tables, apply filters, and use the formula system to define metrics such as MRR, ARPU, CAC, or LTV without rewriting your pipelines.
  • Centralize metric definitions. Publish and certify metrics so every dashboard uses the same logic and context.
  • Query the warehouse directly. Keep data in systems like Snowflake or BigQuery and refresh metrics from those sources on your schedule.
  • Stay audit‑ready. Use descriptions, tags, and history to track how a metric is built and who owns it.

This division of labor works well. ETL handles heavy duty cleaning, joins, and governance. PowerMetrics manages the metric layer, distribution, and decision‑ready dashboards.

Related terms