The CLI Team at Heroku strives to create a CLI user experience that is intuitive and productive. We had “build CLI autocomplete” in the icebox of our roadmap for many years. But if we were going to ship it, it had to complement the existing CLI experience. This is challenging because the Heroku CLI is very dynamic: it comprises user installable plugins, and the data needed for completions is behind an API.

Recently, we spent some time brainstorming the experience we wanted from Heroku CLI Autocomplete and decided it was time. We took “build autocomplete” out of the icebox and shipped it.

This post will discuss the main challenges we faced building Heroku CLI Autocomplete and how we solved...


The Public Cloud Security (PCS) group at Salesforce partners very closely with Heroku engineering to review and advise on new product features across the platform, from infrastructure to applications. One of the most rewarding aspects about this partnership and working on this team for me is when we not only identify security concerns, but take an active role in building safe solutions.

Heroku recently announced support for Active Storage in Rails 5.2, which introduces the ability to generate previews of PDFs and videos. As a security engineer, hearing about a new feature in a product that automatically parses media files definitely grabbed my attention. This post takes a look at...


How to blend a rock-solid CMS and API with the absolute best in front-end tooling, built as a single project and hosted seamlessly on Heroku.

Rails is an incredible framework, but modern web development has moved to the front-end, meaning sometimes you don’t need all the bulk of the asset pipeline and the templating system. In Rails 5 you can now create an API-only Rails app, meaning you can build your front-end however you like—using Create React App, for example. It’s no longer 100% omakase.

An image of four logos, React, Rails, Activeadmin, and Heroku


Rails 5.2 was just released last month with a major new feature: Active Storage. Active Storage provides file uploads and attachments for Active Record models with a variety of backing services (like AWS S3). While libraries like Paperclip exist to do similar work, this is the first time that such a feature has been shipped with Rails. At Heroku, we consider cloud storage a best practice, so we've ensured that it works on our platform. In this post, we'll share how we prepared for the release of Rails 5.2, and how you can deploy an app today using the new Active Storage functionality.

Trust but Verify

At Heroku, trust is our number one value. When we learned that Active Storage...


I sat down with some Ruby friends in Hiroshima last year to have a conversation about just-in-time compilation for Ruby, specifically the new MJIT method-based implementation. Those of you who are already familiar with JITs and how they work might want to skip directly to the interview, the rest of us are going to hang out for a minute and learn about how things presently work in Ruby, and what it is exactly that the MJIT would change.

How does a Ruby program run?

Computers don’t speak Ruby or any other high-level language, they only speak machine language. In a compiled language like C++ you use a compiler to convert all of your C++ code into machine language directly before you run...


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