This blog post is adapted from a lightning talk by Ben Fritsch at Ruby on Ice 2019.

There can be a number of reasons why your application performs poorly, but perhaps none are as challenging as issues stemming from your database. If your database's response times tend to be high, it can cause a strain on your network and your users’ patience. The usual culprit for a slow database is an inefficient query being executed somewhere in your application logic. Usually, you can implement a fix in a number of common ways, by:


Update: On closer inspection, the lock type was not on the table, but on a tuple. For more information on this locking mechanism see the internal Postgresql tuple locking documentation. Postgres does not have lock promotion as suggested in the debugging section of this post.

I maintain an internal-facing service at Heroku that does metadata processing. It's not real-time, so there's plenty of slack for when things go wrong. Recently I discovered that the system was getting bogged down to the point where no jobs were being executed at all. After hours of debugging, I found the problem was an UPDATE on a single row on a single table was causing the entire table to lock, which...


This blog post is adapted from a talk given by Julián Duque at NodeConf EU 2019 titled "Let it crash!."

Before coming to Heroku, I did some consulting work as a Node.js solutions architect. My job was to visit various companies and make sure that they were successful in designing production-ready Node applications. Unfortunately, I witnessed many different problems when it came to error handling, especially on process shutdown. When an error occurred, there was often not enough visibility on why it happened, a lack of logging details, and bouts of downtime as applications attempted to recover from crashes.

Julián: Okay. So, as Brian said, my name is Julián Duque, it will be...


As an experiment to see how static typing could help improve our team’s Ruby experience, we introduced Sorbet into a greenfield codebase with a team of 4 developers. Our theory was that adding static type checking through Sorbet could help us catch bugs before they go into production, make refactoring easier, and improve the design of our code. The short answer is that yes, it did all of that! Read on to learn a little more about what it was like to build in a type safe Ruby.

The Sorbet project's logo

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Over the past four years, the Heroku Runtime team has transitioned from occasional, manual deployments to continuous, automated deployments. Changes are now rolled out globally within a few hours of merging any change—without any human intervention. It's been an overwhelmingly positive experience for us. This post describes why we decided to make the change, how we did it, and what we learned along the way.

Where We...


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