Oct 7, 2016 by Jonathan Hunsucker

Feature Flags at MailChimp

A few weeks ago, someone came into support because they couldn't get past the campaign builder’s recipients step. No amount of poking, prodding, clicking, or URL-mangling would permit them beyond choosing their recipients. Which is to say: they couldn’t click Send. Which is to say: MailChimp was broken. As it turns out, the bug was ...

Oct 6, 2016 by Toby Chappell Systems

Performance Testing with SSDs Pt. 2

Last month, we discussed our history with SSD-based servers and prepared a few tests to determine whether the performance rewards of SSDs would outweigh the risks involved for us going forward. Today, we'll take a closer look at OS tuning, filesystem mounting, and reveal the results of our testing. OS tuning In order to gain ...

Sep 29, 2016 by Aubrey Rhodes API

API v3.0 Updates

At the end of this year, we’ll be retiring the older versions of MailChimp’s API. We announced the sunset earlier this year, but I wanted to provide some updates on improvements we’ve made to API v3.0 and some clarification on our plans. Our API team has been hard at work making it easier to manage ...

Sep 12, 2016 by Toby Chappell Systems

Performance Testing with SSDs, Part 1

At MailChimp, we've historically had mixed feelings about SSD-based servers. Years ago, our servers were hosted by a provider that utilized SSDs for storage, and many of those SSDs ended up failing at the same time. It caused quite a few headaches for the team, and we were hesitant to consider SSDs as an option ...

Jul 1, 2016 by Jordan Conard

Securing Puppet with Hiera-Eyaml Key Rotation

Here at MailChimp, our operations team is in charge of the 1300+ physical servers that keep our app running strong. We couldn’t possibly provision, configure, and maintain all of those servers by hand, so we use a configuration management tool called Puppet to help us out. Puppet allows us to describe how the software across ...

May 25, 2016 by Alan Crissey

How We Built the MailChimp Style Guide

Since its launch in August of last year, MailChimp's public, open source style guide has served as a helpful resource for MailChimp employees and outside organizations alike. Over the past few months, we've received a lot of questions asking how we built it, so we thought we'd shed some light on the topic—along with insight ...