Shorts
TensorFlow Object Detection in PHP
The ONNX Runtime package makes it easy to run TensorFlow models in PHP. This short tutorial will show you how. It’s based on this tutorial from...
August 24, 2022
DVC on Heroku
DVC is a version control system for machine learning datasets and models. It allows you to store large files outside of Git while keeping them...
November 7, 2020
Git LFS on Heroku
Git LFS allows you to version large files while storing them outside of your Git repository. Heroku doesn’t have built-in support for it, so a few...
October 31, 2020
15 More ML Gems for Ruby
I’m happy to announce another round of machine learning gems for Ruby. Like in the last round, many use FFI or Rice to interface with high...
September 24, 2020
Ruby ML for Python Coders
Curious to try machine learning in Ruby? Here’s a short cheatsheet for Python coders. Data structure basics Numo: NumPy for Ruby Daru: Pandas for...
January 23, 2020
16 New ML Gems for Ruby
In August, I set out to improve the machine learning ecosystem for Ruby and wasn’t sure where it would go. Over the next 5 months, I ended up...
January 22, 2020
Daru: Pandas for Ruby
2023 Update: Check out Polars Ruby as well. NumPy and Pandas are two extremely popular libraries for machine learning in Python. Last post, we...
September 18, 2019
Numo: NumPy for Ruby
NumPy is an extremely popular library for machine learning in Python. It provides an efficient way to work with large, multi-dimensional arrays....
September 17, 2019
Emotion Recognition in Ruby
Welcome to another installment of deep learning in Ruby. Today, we’ll look at FER+, a deep convolutional neural network for emotion recognition...
September 13, 2019
Artistic Style Transfer in Ruby
The ONNX Model Zoo has a number of interesting pretrained deep learning models. Thanks to the ONNX Runtime, we can run them in Ruby. Today, we’ll...
September 11, 2019
TensorFlow Object Detection in Ruby
The ONNX Runtime gem makes it easy to run TensorFlow models in Ruby. This short tutorial will show you how. It’s based on this tutorial from...
August 28, 2019
Score Almost Any Machine Learning Model in Ruby
Ruby isn’t a common choice for machine learning, but companies running Ruby can get tremendous value from it. I’m happy to announce it’s now...
August 27, 2019
XGBoost and LightGBM Come to Ruby
I’m happy to announce that XGBoost - and its cousin LightGBM from Microsoft - are now available for Ruby! XGBoost and LightGBM are powerful machine...
August 19, 2019
Modern Encryption for Mongoid
I’m happy to announce that Lockbox now supports Mongoid. This makes it easy to add application-level encryption to your MongoDB documents. Blind...
August 16, 2019
Gem Patterns
I’ve created a few Ruby gems over the years, and there are a number of patterns I’ve found myself repeating that I wanted to share. I didn’t invent...
August 2, 2019
Introducing Searchkick Pro
Note: Searchkick Pro is no longer available. Searchkick makes it easy to add intelligent search to Rails applications. It was launched in 2013 back...
August 1, 2019
Lockbox: Now with Types
A new version of Lockbox was just released with support for types, making it easier to encrypt non-string fields. Previously, you’d need to perform...
July 22, 2019
Ruby with OpenSSL 1.1
Some Ruby features like scrypt and hkdf require OpenSSL 1.1. Here’s how to make it work on Mac: Install rbenv and OpenSSL 1.1 Install Ruby Open an...
July 11, 2019
Securing User Emails in Rails with Lockbox
This is an update to Securing User Emails in Rails with a number of improvements: Works with Devise’s email changed notifications Works with...
July 10, 2019
Blind Index 1.0
Blind indexing is an approach to securely search encrypted data with minimal information leakage. I’m happy to announce that Blind Index 1.0 was...
July 9, 2019
Modern Encryption for Rails
Encrypting sensitive data at the application-level is crucial for data security. Since writing Securing Sensitive Data in Rails, I haven’t been...
July 8, 2019
Why and How to Keep Your Decryption Keys Off Web Servers
Suppose a worst-case scenario happens: an attacker finds a remote code execution vulnerability and creates a reverse shell on one of your web...
March 28, 2019
Argon2 with Devise
bcrypt has been a great choice for safely storing passwords. However, as time has passed, a better alternative has emerged: Argon2. OWASP now...
March 23, 2019
Hybrid Cryptography on Rails
Hybrid cryptography allows certain servers to encrypt data without the ability to decrypt it. This can greatly limit damage in the event of a...
February 28, 2019
Introducing pdscan: Scan Your Data Stores for Unencrypted Personal Data
It's important to understand where personal data is stored in your applications. Personal data that’s not encrypted at the application level is...
February 25, 2019
Securing Sensitive Data in Rails
It feels like data breaches are showing up every week in the news. If you haven’t taken a second look at how you’re storing sensitive data, now is...
November 20, 2018
Postgres SSLMODE Explained
When you connect to a database, Postgres uses the sslmode parameter to determine the security of the connection. There are many options, so here’s...
November 18, 2018
Active Storage S3 Client-Side Encryption
Use client-side encryption to encrypt your data before sending it to S3. You can provide an encryption key to use directly or a KMS key for...
November 12, 2018
Scaling the Monolith
Many companies start out with a single web application. As the team and codebase grow, things feel less organized and common tasks like booting the...
November 7, 2018
Rails, Meet Data Science
Organizations today have more data than ever. Predictive modeling is a powerful way to use this data to solve problems and create better...
October 29, 2018
Introducing Archer: Rails Console History for Heroku, Docker, and More
Many companies today run infrastructure where machines or containers can be replaced at any time, so you can’t depend on them for permanent...
October 23, 2018
Strong Encryption Keys for Rails
Encryption is a common way to protect sensitive data. Generating a secure key is an important part of the process. attr_encrypted, the popular...
October 22, 2018
Verify Slack Requests in Rails
Slack signs its requests so you can verify they’re authentic. Here’s a method you can use in your Rails controllers for it. 
September 14, 2018
Vault for PKI
Here’s how to use Vault for public key infrastructure. Update: Vault now has a great article on this Install the latest version of Vault and jq...
July 21, 2018
Backsolving in Ruby
QR decomposition is a stable way to solve linear regression. You can use the extendmatrix gem to do decomposition in pure Ruby. Givens rotations...
June 28, 2018
Jupyter + Rails
Jupyter notebooks are a great alternative to the Rails console for doing exploratory data analysis and building predictive models. Here’s how to...
June 19, 2018
Bulk Upsert in Ruby/Rails
The upsert gem is great for individual upserts, but for performant bulk upserts, use the activerecord-import gem. Add a unique index on the columns...
June 16, 2018
Securing User Emails in Rails
There is an updated version of this post. The GDPR goes into effect next Friday. Whether or not you serve European residents, it’s a great reminder...
May 14, 2018
Anonymizing IPs in Ruby
With the GDPR just around the corner, here are two useful ways to protect your users’ IP addresses. Both support IPv4 and IPv6, and are included in...
May 5, 2018
TPC-H with Postgres
TPC-H is a database benchmark. Create the database and load the schema Generate data Load the data Generate queries Run queries Bonus: Add Indexes...
April 29, 2018
TPC-DS with Postgres
TPC-DS is a database benchmark. Create the database and load the schema Generate data Load the data Generate queries Run queries Bonus: Add Indexes...
April 29, 2018
Package Your JavaScript Libraries With Rollup
Rollup is a great tool for building libraries. “Webpack for apps, and Rollup for libraries” Run: Add to package.json: Add dist/ to your .gitignore....
March 27, 2018
Securing Database Traffic with PgBouncer and Amazon RDS
Securing database traffic inside your network can be a great step for defense in depth. It’s also a necessity for Zero Trust Networks. Both Amazon...
November 27, 2017
A Short Guide to Metrics
Simple rules to follow when creating metrics Over time: You must see how metrics change over time. Ideally you can view them by day, week, and...
November 5, 2017
Trying Out Vault for Postgres Credentials
Install Vault, as well as JQ for JSON parsing Start the dev server Then open another window. For this demo, we’ll create a new Postgres database....
November 5, 2017
Client-Side Encryption with AWS and Ruby
AWS makes it easy to enable server-side encryption on many of its services, but it also provides ways to do client-side encryption well. Here are a...
September 23, 2017
PgHero 2.0 Has Arrived
It’s been over 2 years since PgHero 1.0 was released as a performance dashboard for Postgres. Since then, a number of new features have been added....
August 8, 2017
Introducing Dexter, the Automatic Indexer for Postgres
Your database knows which queries are running. It also has a pretty good idea of which indexes are best for a given query. And since indexes don’t...
June 26, 2017
Bootstrapping Postgres Users
Setting up database users for an app can be challenging if you don’t do it often. Good permissions add a layer of security and can minimize the...
May 23, 2017
New Rails App Checklist
How I personally start new apps Create Project Get the latest version of Rails Create a new app Don’t fret too much over the name - you can easily...
March 30, 2017
Just Table It
When it comes to data, you can mistakenly optimize by trying to choose the “right” technology for the job. Often, the best choice is right in front...
January 13, 2017
The Safely Pattern
The Safely Pattern is a simple one. It allows you to tag non-critical code by wrapping it in a function. It’s built on top of exception handling...
December 6, 2016
Large Text Indexes in Postgres
Note: This article was written for Postgres 9.6 and below. For Postgres 10+, use hash indexes instead. An index on a sufficiently large text column...
October 7, 2016
navigator.sendBeacon and Rails
navigator.sendBeacon is a neat new API. It allows you to send an asynchronous POST request without delaying the page unload. To prevent Can't...
September 1, 2016
Installing Presto for Mac
Presto is a “Distributed SQL Query Engine for Big Data” that gives you the ability to join across data stores! 
Server The easiest way to...
August 4, 2016
Google OAuth with Devise
Here’s a quick guide to setting up Google OAuth as your app’s exclusive authentication method Add to your Gemfile And run Create a User model In...
July 18, 2016
Hardening Devise
A few basic steps to make your Devise setup more secure Send notifications for important events Like a user changing his or her email or...
July 7, 2016
Error Reporting in R
R supports global error handling, making it easy to report all errors without individual tryCatch statements. Create a file to source at the start...
May 11, 2016
Startup Security
A few simple steps to keep you secure. Require 2-factor authentication for important accounts, like Gmail and GitHub. Require hard drives to be...
April 4, 2016
Learn Data Science
R and Python are two popular languages for data science. We use both at Instacart. This is a short guide for R. It’s quick and everything is...
January 12, 2016
Adding CSP to Rails
Content Security Policy can be an effective way to prevent XSS attacks. If you aren’t familiar, here’s a great intro. To get started with Rails,...
November 29, 2015
Security Checks
You should see verify return:1 for each certificate in the chain. Host header injection Read about it here. Your site is vulnerable if evilsite.com...
October 26, 2015
Data Science SQL
Root mean squared error Mean absolute error Mean error Median - get it here
September 10, 2015
Rails on Heroku
The official guide is a great place to start, but there’s more you can do to make life easier. 
Based on lessons learned in the early...
August 12, 2015
R and Database URLs
Note: This approach is now built into the dbx package To use a DATABASE_URL with R, do: Postgres MySQL 
August 10, 2015
The Origin of SQL Queries
Do you know what part of your application is generating that time-consuming database query? There’s a much simpler way than grep. Add comments to...
July 15, 2015
irbrc
My simple ~/.irbrc
June 29, 2015
Rails on Dokku
To open a Rails console, run: Migrations
May 31, 2015
Dokku on DigitalOcean
Your very own PaaS Create Droplet Create new droplet with Ubuntu 16.04. Be sure to use an SSH key. Install Dokku And visit your server’s...
May 31, 2015
Host Your Own Postgres
Get running with the last version of Postgres in minutes Set Up Server Spin up a new server with Ubuntu 16.04. Firewall Automatic...
May 31, 2015
The Two Metrics You Need
When interviewing candidates for Instacart’s first site reliability engineer, I volunteered to cover monitoring as one of my topics. I’d start by...
April 30, 2015
Scaling Reads
Note: This approach is now packaged into a gem 
One of the easier ways to scale your database is to distribute reads to replicas. Desire...
March 31, 2015
attr_accessible to Strong Parameters
Running Rails 4 with attr_accessible? Upgrade in three safe and easy steps 1 First, log all instances of forbidden attributes. Add to...
March 31, 2015
PgBouncer Setup
In under 5 minutes Get Started Here’s the flow: You can install PgBouncer on the same server as Postgres or a separate server. For Amazon RDS, you...
March 31, 2015