| #433 — January 17, 2019 | 
| Ruby Weekly | 
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| 3 ActiveRecord Mistakes That Slow Down Rails Apps — The culprits are  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:  David Bourguignon | 
| RubyFlow: A Ruby Community Link Blog — RubyFlow 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. RubyFlow | 
| 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. Machinio | 
| 💻 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. Vettery | 
| 📘 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. BoltOps | 
| 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 —  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 Netflix | 
| Trav3: API Client for Travis CI API Version 3 Daniel P. Clark |