#433 — January 17, 2019

Read on the Web

Ruby Weekly

3 ActiveRecord Mistakes That Slow Down Rails Apps — The culprits are count, where, and present?, and here’s advice that you will, no doubt, use from someone who literally wrote a book on Rails performance.

Nate Berkopec

Using Ruby in 2019 — If you need a few reasons to be excited about being a Rubyist this year (or fight off the yearly “Ruby is Dead” posts) then this is for you.

Jason Charnes

eBook: Best Practices for Optimizing Postgres Query Performance — Learn how to get a 3x performance improvement on your Postgres database and 500x reduced data loaded from disk in this free pganalyze eBook.

pganalyze sponsor

A New Form of Lambda Composition in Ruby 2.6 — 2.6 brings a couple of new proc composition operators: << and >>, which allow easy, intuitive, and (dare I say) functional composition of procs.

David Bourguignon

RubyFlow: A Ruby Community Link BlogRubyFlow is a community blog we run (all you need is a GitHub account to post) and has become one of our main sources of links, so if you have a library, tutorial, or something else Ruby related, post about it there.


Cuprite: A Headless Chrome Driver for Capybara — A pure Ruby (no Java, Selenium, or WebDriver stuff needed here) driver that lets you run Capybara-based tests on a headless Chrome browser.


💻 Jobs

Senior Web Developer at Dr. Bill (Remote OK) — Dr. Bill helps Canadian doctors save time by streamlining their billing. Help lead our team into the next phase of growth.

Dr. Bill

Senior Backend Engineer - Ruby on Rails (Berlin - On site) — Growing market and opinion research company, with a modern JavaScript and Ruby on Rails stack. We also have a team boat. Join us.

Dalia Research

Find A Job Through Vettery — Vettery specializes in developer roles and is completely free for job seekers.


📘 Articles & Tutorials

How to Reduce Test Interference in Minitest — If you’ve ever had issues with Rails test leaking state between test cases, here’s a gem that’ll run one test per process.

Greg Navis

Partial Application in Ruby — Partial application, or currying, is a technique that uses a function to create new functions of lower arity (meaning, they take fewer arguments.)

Igor Morozov

Extracting Text From Images Using Ruby — Using Tesseract, MiniMagick, & OpenCV to extract subtitle text from screenshots (to categorize memes, no less!)

Ahmed Saleh

Performance Monitoring and Error Tracking for Rails — With deep process inspection - diagnose runaway memory leaks and deadlocked/zombie/high CPU processes.

Baseline Red sponsor

Serverless Slack Commands with Ruby: AWS Rekognition — Using the Jets framework on AWS Lambda to create a Slack command that scrapes and filters images.

Tung Nguyen

Crafting User Notifications in Rails with Active Delivery — Someone has created a framework to handle notification delivery that can use email, SMS, or just about any notification type you can dream up.

Vladimir Dementyev

Building a Serverless API with the Jets Ruby Serverless Framework — We first mentioned the Jets framework back in issue 431, but here’s a proper tutorial showcasing its usefulness.


Rails 6 Adds ActiveRecord::Relation#pick — A shortcut to select the first value for one or many attributes from a set of records.

Prathamesh Sonpatki

Understanding the Eigenclass in Less Than 5 Minutes — A bold claim for a somewhat obtuse concept?

Mehdi Farsi

🔧 Code & Tools

Suggest: Tells You Which Method Does The Thing You Want to Do[1,2,3].what_returns? 1 # => [:first, :min]

Josh Bodah

TTY::Pie: Draw Pie Charts in Your Terminal Window — The latest release adds a way to format legend labels however you like.

Piotr Murach

Shop Like a Developer – Discover and Experiment with Hot New Cloud Services 🔥

Manifold sponsor

FastJsonapi: A Super-Fast JSON:API Serializer for Ruby Objects


Trav3: API Client for Travis CI API Version 3

Daniel P. Clark