Slack is the leading global collaboration hub that makes people’s working lives simpler, more pleasant and more productive. From global Fortune 100 companies to corner markets, businesses and teams of every kind use Slack to bring the right people together with all the right information. Whereas just two years ago the product had 2 million daily active users (DAUs), today it boasts over 6 million. Unfortunately, with quick growth come tough growing pains, and Slack was (and still isn’t) immune to them.

Around April of last year, our product was plagued with relentless performance-related outages facing our largest customers. Instead of shipping scrappy, short-term fixes in the hopes that we could survive another Monday morning, we opted to address the root problem and completely change our data model around channels and channel membership. This is the tale of that undertaking, following one engineer (me!), through many obstacles and hiccups she overcame to boost both application performance and company-wide developer productivity.

You’ll walk away having learned how to:

Convince your leadership that the intimidating, months-long rewrite is worth it
Document the complex process for teammates and leadership alike
Prepare for the unexpected, and, most importantly
Stay optimistic!