Article Roundup - April 19, 2019

Why software projects take longer than you think – a statistical model
Estimating software projects is hard and the bigger they get the harder it gets. Ever notice that the sum of your estimates is usually wrong? In this article, the author talks about some ideas they have had about project estimation and walks through some statistics around it.

Avoiding Double Payments in a Distributed Payments System
It’s important to not double charge your customers. Airbnb has been changing its system architecture and needed to come up with a generic solution for idempotency. This article walks through how they did.

Enough with the User Stories already!
I’ve seen both good and bad user stories. The unfortunate thing is a lot of the user stories haven’t been particularly useful. They either have excessive detail or not enough and they never seem to capture what needs to be done. This article highlights a few topics from Behavior-Driven Development (BDD) that may prove more useful for leadership and for developers.