January 21, 2019

Set dependencies between Airflow DAGs with ExternalTaskSensor

Problem You are an analyst/data engineer/data scientist building a data processing pipeline in Airflow. Last week you wrote a job that peforms all the necessary processing to build your sales table in the database. This week, you are building a customers table that aggregates data from your previous sales table. Should you add the necessary customers logic as a new task on the existing DAG, or should you create an entirely new DAG? Read more

June 10, 2018

Redshift function of the week: RATIO_TO_REPORT

A common use-case A very common scenario one comes across while performing data analysis is wanting to compute a basic count of some event—such as visits, searches, or purchases—split by a single dimension—such as country, device, or marketing channel. Quite often this arises as an intermediate need while working towards some other primary task. Let’s work with a simple example: you’d like to get a rough sense of how many of your company’s orders come from from each country. Read more

June 5, 2017

Essential productivity apps for Mac users

Once a year I try to reevaluate my “personal tech stack” to see if I am using fundamental tools as effectively as possible. Not just bigger tools such as todo lists, calendars, and note-taking, but also the smaller utility apps that get used so frequently they blend into our daily work routine. Our fluency with the tools we use every day is the foundation of personal productivity1 , so it makes sense to optimize even small interactions2 such as switching between windows. Read more

July 17, 2016

Test your product assumptions with GA Intelligence Alerts

A good chunk of the job of being a PM or analyst involves spending time analyzing patterns of user behaviour, often to answer specific questions. Over time though, we build up mental models and heuristics which allow us to use our prior knowledge to answer questions more quickly. More knowledge is good, right? On one hand, past experience calibrates our sense of prior probability, which allows us to make better decisions in noisy contexts. Read more

June 7, 2016

Book review: Remote Research (user research)

This is a brief review of the book Remote Research, and a summary of points that resonated with me. Key Concepts Moderated research – Real-time interaction with a user that is time-expensive, but is easier to discover unanticipated insights due to the greater “texture” of the interaction. “Moderated research allows you to gather in-depth qualitative feedback: behavior, tone-of-voice, task and time context, and so on. Moderators can probe at new subjects as they arise over the course of a session, which makes the scope of the research more flexible and enables the researcher to explore behaviors that were unforeseen during the planning phases of the study. Read more

© Geoff Ruddock 2019