• Let's Encrypt and NearlyFreeSpeech.NET

    At the time of this writing, this blog is hosed on NearlyFreeSpeech.NET, and delivered securely over TLS with a certificate from Let’s Encrypt. I previously wrote about how I obtained the first certificate and how to renew it. The process is now even easier, because NearlyFreeSpeech.NET automates the setup and renewal for it’s members.

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  • The REPL: Issue 51 - October 2018

    The Architecture No One Needs

    Greg Navis discusses why he thinks single-page applications (SPAs) are almost always worse than traditional, multi-page web application. I tend to agree: Most of the time, it adds engineering complexity for not much benefit. I think this is particularly the case when using Elixir and Phoenix, since their performance is spectacular. Phoenix Channels already provide a way for updating content on a page without reloading, and the upcoming Live View promises to make it even better.

    Elapsed time with Ruby, the right way

    This post by Luca Guidi explains with great detail how calculating elapsed time in Ruby can have it’s pitfalls. The TLDR:

    ## Don't do this:
    starting = Time.now
    # time consuming operation
    ending = Time.now
    elapsed = ending - starting
    elapsed # => 10.822178
    ## Do this:
    starting = Process.clock_gettime(Process::CLOCK_MONOTONIC)
    # time consuming operation
    ending = Process.clock_gettime(Process::CLOCK_MONOTONIC)
    elapsed = ending - starting
    elapsed # => 9.183449000120163

    Automate Repetitive Tasks with Composed Commands

    In this post, the [[Atom]] team explains how you can create composed commands from existing commands already available in your editor. This feature seems great for automating tasks. I haven’t composed any commands of my own just yet, but I think this is a great addition.

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  • Managing Versions With asdf

    Three years ago, I switched my ruby version manager from rvm to rbenv. Since then, I’ve been using rbenv without complaint. It just works. I now find myself working on more complex projects, that needs specific version of Ruby, Elixir, Postgres, Terraform and others.

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  • The REPL: Issue 50 - September 2018

    How to teach yourself hard things

    Julia Evans writes a great article on how to learn… to learn. In her traditional straight-forward fashion, she describes the method she has used to learn things that are difficult. She breaks the process down into approachable skills that anyone can learn (e.g ask questions, have confidence in your knowledge). I also recommend following her on twitter. She posts comics often about unix tools: I always learn something knew from them.

    Distributed Agreement on Random Order – Fun with Lamport Timestamps

    If you’ve ever done some digging into distributed computing, you will have heard of Lamport Clocks. In this post, Quentin Duval, details step by step on how to construct an application that uses Lamport’s algorithm for reaching agreement on the order of events across a distributed system.

    Upgrading GitHub from Rails 3.2 to 5.2

    Working as a Rails developer, I’ve found myself a few times in the same situation GitHub was: Relying on an old version of a framework that has now become a liability, and upgrading is anything but straight forward. In this post, Eileen Uchitelle describes the strategy that GitHub used to upgrade. I especially like the section about lessons learned: It’s one of my favorite things about the software community. The willingness to share with others allows us to learn from each other. Thanks Eileen!

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  • 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.

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