Data on Connor Charles

Identity stitching in a distributed environment

Mon, 20 Jul 2026 00:00:00 +0000

In this post, I will discuss how we use the identifiers attached to Snowplow events to build a consistent view of a consumer as they move between browsers and devices. The goal is to provide a single identifier for each consumer.

What is identity stitching?

Identity stitching in this context is the process of linking identifiers together from consumer data to build a unified view of each individual. When a consumer interacts with a website or app in Snowplow, the events they generate contain various identifiers such as cookies, mobile device IDs, and, if they are logged in, their account ID. Identity stitching allows us to link these together so that we have a single event timeline and profile for each consumer, even if they use multiple devices or browsers.

Transferring billion row datasets from BiqQuery into Postgres

Tue, 14 Jul 2026 00:00:00 +0000

A common challenge in data engineering is figuring out how to move a large dataset in one structure, format or cloud region and transform it into another without creating a large cloud bill or having to wait a long time for a batch job to complete. At Autotrader, we do a lot of batch processing using dbt and BigQuery. This often results in datasets that we want to then export to operational datastores such as Postgres or Mongo. We then surface these datasets in embedded analytics products, which require the low latency that Postgres and Mongo can deliver.

Hack Diary: Natural Language Queries of Data Using a Semantic Layer

Mon, 22 Jun 2026 00:00:00 +0000

Recently, my team at Autotrader ran a hack on ways to improve the experience of the data platform for our colleagues. The aim of this hack wasn’t necessarily to produce production-ready software, but to give the team exposure to AI-based workflows and semantic layers. One of the biggest pain points we have is that we have a lot of data, dashboards and reports and it can be hard to find the right one. Especially in meetings where sometimes someone will ask “How many X did we have last week?” and then someone might have to step back from the conversation and find the right dashboard by which point the meeting has already moved on.