Blog

Notes from the transition

Writing about what I learn as I move from the field into analytics. Engineering intuition meets data science practice.

The Problem of Streaks and Sessions

Islands-and-gaps problems keep resurfacing on LeetCode, StrataScratch, and DataLemur under different names — login streaks, active sessions, consecutive runs. This post works through the solutions to these problems in three levels.

Jul 19, 2026 12 min read #sql#window-functions#islands-and-gaps Read post →

The Window Function Trick That Saved Me a CTE

I was reaching for another CTE just to compute a group total, then realised you can nest an aggregate inside a window function and skip it entirely.

Jul 1, 2026 5 min read #sql#window-functions#energy Read post →