As well as being an active contributor to well-known open-source projects, I am also the author and maintainer of a number of libraries of my own.


Mobility is a library for storing translations of a model in a Ruby application, for example translations of posts in a blog. It provides a seamless interface for storing such translations in the same way you would store untranslated model data.

While there are other libraries in Ruby that do this, Mobility’s design is unique in that it allows you to store your translations in whatever format you want. This makes it very flexible and adaptable to many different usage scenarios (hence the name).

Mobility is used in a growing number of companies with international customers. For a deep dive into Mobility’s design, see my recent talk at RubyConf 2018.


Wharel helps you write concise Arel queries with ActiveRecord using Virtual Rows inspired by Sequel.

Although similar in spirit to other gems which provide block-based interfaces for querying with Arel, Wharel is much much smaller. In fact, the core of the gem is only 30 lines long! It uses a single BasicObject as a clean room to evaluate the query block. That’s really all there is to it.

For a more detailed explanation of the implementation, see this blog post.


Say you want to override some methods from a gem so you can add some instrumentation (measure performance or something). If you’re not careful, you may change the “visibility” of those methods: a method was originally private, but your override makes it public. This is not ideal and can lead to subtle bugs.

Invisible solves this problem. Simply extend a module with Invisible, define your methods, and Invisible will take care of ensuring that when you include (or prepend) the module somewhere, any methods it overrides will keep their original visibility. Invisible does this in just a dozen lines of code, check it out for yourself.