Building a Data Pipeline from Scratch - Day1 Consulting

Building a Data Pipeline from Scratch

October 12, 2025 Day1 Team 4 min read
#data#analytics#pipeline#bi


You've launched. You have users, maybe even paying customers. But if you're being honest with yourself, you're flying blind.

You make decisions based on gut feelings, a few customer emails, and what you think is happening. You have data—somewhere. Sales numbers are in Stripe, website clicks are in Google Analytics, user info is in your production database. But they don't talk to each other. Answering a simple question like "Which marketing channel brings in our best customers?" feels impossible.

If this sounds familiar, you're not alone. This isn't a technical problem; it's a clarity problem. Let's talk about how to fix it.

From Guesswork to Knowing: A Story

I once worked with a founder who sold beautiful, handmade soaps online. She was passionate and had great instincts, but her business decisions were pure guesswork. She'd run a 20% off sale because "it felt like a good time" or discontinue a scent based on a single negative comment.

She was drowning in data she couldn't use. Her "analytics" was a folder of messy Excel exports that took hours to piece together. It was a recipe for burnout.

Together, we built her first real data pipeline. It sounds intimidating, but it's just a system for getting all your data into one place and making it tell a story. Here’s how we did it, step-by-step.

Step 1: We Asked a Simple Question (Collection)

The biggest mistake people make is trying to track everything at once. We didn't start with complex KPIs. We started with one simple, painful question: "Where do people give up when trying to buy soap?"

To answer this, we added little digital breadcrumbs to the website. Every time a user did something important—viewed a product, added it to their cart, started checkout, completed a purchase—the site would send a tiny, anonymous message. This is called event-based tracking.

You don't need to build this yourself. Tools like Segment or Snowplow make it easy to get started. The goal isn't to "boil the ocean," it's to illuminate one dark corner of your business.

Step 2: We Gave the Data a Home (Storage)

At this point, we had data coming from our website, from Stripe (payments), and from Facebook Ads. It was still a mess. Trying to match a "user" from the website to a "customer" in Stripe was a nightmare.

The solution was to give all this data a single home: a data warehouse.

Don't let the name scare you. A data warehouse is just a special kind of database designed for asking big questions. It's like having a clean, organized library for your business data instead of having books piled up in every room of your house. Crucially, it's separate from your main application database, so your analytics work won't ever slow down your app for actual users.

We chose BigQuery because it's cheap and easy to start with, but Snowflake or Redshift are also great options.

Step 3: We Cleaned Up the Mess (Transformation)

Getting all the data into the warehouse was a huge step, but it was still messy. A "sale" in Stripe was recorded in cents, but our ad spend in Facebook was in dollars. Timestamps were in different formats.

This is where the most important work happens: transformation. This step is about cleaning, organizing, and creating a single, reliable "dictionary" for your business. We created one clean table called orders that joined the messy data from three different systems into something anyone could understand.

A tool called dbt (Data Build Tool) is the undisputed champion here. It lets you write simple rules in SQL to define your business logic, turning raw, confusing data into clean, trustworthy models.

Step 4: The "Aha!" Moment (Visualization)

This is the payoff. We connected a tool called Metabase to our new, clean data in the warehouse. For the first time, the founder could see her entire business on one screen.

The "aha!" moment came within an hour. We discovered that customers who watched the 30-second "how our soap is made" video were three times more likely to make a purchase. She had been thinking about deleting that video to simplify the site. The data proved it was her single most effective marketing asset.

She stopped guessing and started knowing.

You Can Stop Guessing, Too

Building a data pipeline isn't about having fancy tools or hiring expensive consultants. It's an investment in clarity. It's the difference between flying blind and having a map.

Start small. Pick one question you desperately want to answer. Follow the data, give it a home, clean it up, and listen to the story it tells you. That's how you become data-driven.