Ylan Segal

The REPL: Issue 49 - August 2018

Cost of a Join

Brian Davis writes a detailed post of how expensive it is to do join queries in postgres. The details are very interesting, as is the conclusion: Join operations are usually cheap.

Elixir: a few things about GenStage I wish I knew some time ago

I’ve recently started working on an Elixir project that seems perfectly suited to use GenStage. In this article Andrei Chernykh complements the GenStage documentation and explains how to use it in an approachable manner.

What they don’t tell you about event sourcing

Hugo Rocha writes about the pitfalls of using event sourcing. Like most engineering techniques, it is not a perfect fit for every situation. In fact, I believe event sourcing is a sufficiently different paradigm to traditional CRUD applications that it makes it difficult to approach in a iterative manner that other techniques can be incorporated into existing systems.

Why JWTs Suck as Session Tokens

Randall Degges writes a good primer on what JWT tokens are, what security guarantees they give, and what problem they are a good solution for. Namely, using them in distributed systems to reduce inter-service calls to verify authentication (or other claims). As the title not-so-subtly suggests, they are not great as session tokens. Most web frameworks already have this problem solved. There is no need to re-invent wheels that are rolling just fine.