Thursday September 28, 2023

Issue summary:
From 8:00 AM PDT to 11:00 AM PDT on Thursday, September 28, 2023, a small number of users experienced delays in Slack, including sending and editing messages, and loading channels.

Upon investigation, we determined that a specific task in our backend was producing too many file deletion events and overloading our servers, resulting in these delays.

We implemented a fix to reduce the load on our servers and this resolved the issue for all affected users.

5:49 PM PST

We resolved the latency issues with Slack. Impacted actions like sending or editing messages have been restored. We appreciate you bearing with us as we worked to get things back to normal.

11:28 AM PST

Some users may be seeing signs of improvement, but we’re still monitoring the situation. We’ll be back once we have another update to share. Thank you for your patience as we sort this out.

11:27 AM PST

We have determined that less than 1% of API calls are failing.

As this may impact certain actions like sending or editing messages, we recommend that users reattempt the action if it has failed. We hope to resolve this shortly and will be back with an update once new information becomes available.

10:23 AM PST

A small number of users are reporting latency with Slack, including delays in sending or editing messages.

We're investigating the issue and will share an update once we have more information.

10:02 AM PST

Issue summary:
On September 28, 2023 from approximately 11:54 AM PDT to 3:15 PM PDT, some Slack users experienced trouble receiving two-factor authentication (2FA) codes and therefore were unable to sign into Slack.

We determined this was caused by an upstream 2FA provider issue impacting code deliveries to US-based AT&T and Verizon devices. We monitored communications from the provider and confirmed Slack users could successfully sign in once the upstream issue was resolved.

3:55 PM PST

Our upstream provider is reporting that the issue is now resolved. Users should now be able to receive 2FA codes on US-based AT&T and Verizon devices as expected.

Thank you again for your patience, and we apologize for the disruption.

3:42 PM PST

Our upstream provider is reporting some signs of recovery. We will provide another update once we have more details to share.

We appreciate your patience while we sorted this out.

2:20 PM PST

We're actively investigating this issue and will be back with another update as soon as we have more information to share.

1:36 PM PST

Our 2FA upstream provider is currently experiencing issues, which prevents Slack native 2FA code from arriving to US-based AT&T and Verizon devices.

We’re on the case and will provide another update once we have more details to share. We’re sorry for the disruption.

1:05 PM PST