• 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 our rate of change to meet business needs. • Defining the problem System requirements change as businesses evolve whether that be due to changes in customer expectations, load & scale or response to business needs. • In this case analysis showed two critical trends: - Slack has become more mission critical for our customers, increasing expectations of reliability for the product as a whole and for specific features each company relies on.

Article Summaries:

  • 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 our rate of change to meet business needs. Defining the problem System requirements change as businesses evolve whether that be due to changes in customer expectations, load & scale or response to business needs. In this case analysis showed two critical trends:
  • Slack’s Deploy Safety Program, launched in mid‑2023, has cut customer‑impact hours from peak levels by 90% as of January 2025, marking a significant reliability improvement. The initiative arose after analysis showed that 73 % of customer‑facing incidents were triggered by Slack‑related code deployments, and that customers deemed interruptions longer than ten minutes as disruptive. Slack set “North Star” goals-automated detection and remediation within 10 minutes, manual within 20, and pre‑emptive detection before 10 % of the fleet is affected-while maintaining development velocity. A new metric, measuring hours of high‑severity, change‑triggered incidents, now tracks progress toward better customer sentiment.

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