It’s mid 2023 and we’ve identified some opportunities to improve our reliability. Fast forward to January 2025. Customer impact hours are reduced from the peak by 90% and continuing to trend downward. We’re a year and half into the Deploy Safety Program at Slack, improving the way we deploy, uplifting our safety culture and continuing…
#deployment
7 posts
7 Oct 2025
18 Jan 2024
Most of Slack runs on a monolithic service simply called “The Webapp”. It’s big – hundreds of developers create hundreds of changes every week. Deploying at this scale is a unique challenge. When people talk about continuous deployment, they’re often thinking about deploying to systems as soon as changes are ready. They talk about microservices…
18 Feb 2022
In 2021, we changed developer testing workflows for Webapp, Slack’s main monorepo, from predominantly testing before merging to a multi-tiered testing workflow after merging. This changed our previous definition of safety and developer workflows between testing and deploys. In this project, we aimed to ensure frequent, reliable, and high-quality releases to our customers for a…
19 Nov 2017
During my career as a software developer, I have seen the release frequency increasing steadily. When I started, it would take 12 to 18 months for new features to reach the customer. Years later the frequency increased, so deployment to … Continue reading →
11 Dec 2011
Last year Zone-H reported a record number of 1.5 million websites defacements. 1 million of those websites where running Apache. When it comes to configuring a web server, some people tend to turn everything on by default. Developers are happy because the functionality that they wanted is available without any extra configuration, and there is […]
21 Jul 2008
I needed to automate the task of synchronizing files from one server to another, so I wrote a Phing task. Finally today I found some time to finish writing the documentation. Overview FileSyncTask is a Phing extension for Unix systems which synchronizes files and directories from one location to another while minimizing data transfer. FileSyncTask […]
22 Jun 2008
Phing allows you to use SQL to define changes to your database schema, making it possible to use a version control system to keep things synchronized with the actual code. A common way to automate development and deployment tasks is by writing shell scripts, however, Phing provides some advantages over shell scripts for task automation. […]