In tech, incident management often feels like playing whack-a-mole. You fix one thing, and boom—another problem pops up. Over and over again. Exhausting. And most of the time? Totally avoidable.
Here’s the usual scene: engineers, architects, and the CTO, gathered around a virtual table with too much caffeine and not enough sleep. Another post-mortem. Another round of “What went wrong?” Everyone hoping this time will be different. Spoiler alert—it’s usually not.
Why? Because post-mortems have become ritual cleanup. We write lessons learned, tuck them away in some dusty Confluence page, and move on... until the next outage knocks.
What if we stopped reacting and started predicting?
That’s where pre-mortems come in. Think of them as the post-mortem’s no-nonsense older sibling—the one who sees trouble coming and calls it out early.
Black Friday Blow-Up
Picture this: an e-commerce team is prepping for Black Friday. They’re expecting traffic to triple. So what do they do? Push a brand-new microservices architecture live. On a Friday.
By mid-afternoon, checkout is crawling. Cart abandonment jumps from 5% to 35%. Poof—hundreds of thousands gone. The post-mortem takeaway? “We didn’t account for the load.” You don’t say.
Now imagine they ran a pre-mortem. They could’ve asked:
- What if service X gets hammered?
- Do we have a rollback plan?
- How does this setup hold under stress?
A few chaos experiments—simulating traffic spikes and service slowdowns—might’ve saved the day. In high-stakes situations like this, testing failure before it happens isn’t a luxury. It’s survival.
Monolith Migration Meltdown
Let’s talk about another classic: the dreaded monolith migration.
Company X decides to replace their old legacy stack with something shiny and cloud-native. Months of planning. Countless hours in meetings. Then... go-live day.
Minutes in, systems start falling like dominoes. 90% of API calls throw 500 errors. Support queues explode. Customers are furious. And the post-mortem gem? “No failover was configured.” Oof.
A pre-mortem could’ve helped them ask:
- Where are the single points of failure?
- What happens during a partial outage?
- Are we tracking the right signals to catch this early?
They could’ve tested failure paths, tuned alerts, and added some guardrails—before flipping the switch.
So... What Is a Pre-Mortem?
A pre-mortem is simple. You imagine the project has failed. Spectacularly. Then ask: what went wrong?
It’s not about guessing—it’s about pressure-testing reality:
- Where might this break?
- Which parts are fragile?
- What’s most likely to go sideways?
If you’re working on a distributed system, this isn’t optional. It's essential. These systems don’t just fail—they compound their failures.
Chaos Docs: Not Just Buzzwords
Chaos docs capture what your team believes the system should do under stress. Not just diagrams and uptime goals—but real thinking:
- What could go wrong?
- What are our limits?
- How do we bounce back?
Done right, chaos docs turn gut instincts into shared knowledge.
They work as:
- Pre-flight checklists for risky rollouts
- Decision logs for tradeoffs and failure points
- Training tools for new hires and drills
They’re also living documents. Every incident? Fuel to improve them.
Try This
Want to simulate API strain? Start with something like:
# Simulate load on your product API
for i in {1..1000}; do
curl -X GET "http://your-ecommerce-site.com/api/products" &
done
Need high availability? Here’s a Terraform snippet:
# Set up AWS load balancer
resource "aws_elb" "app_lb" {
name = "app-load-balancer"
availability_zones = ["us-west-2a", "us-west-2b"]
listener {
instance_port = 80
instance_protocol = "HTTP"
lb_port = 80
lb_protocol = "HTTP"
}
health_check {
target = "HTTP:80/"
healthy_threshold = 3
unhealthy_threshold = 5
timeout = 5
interval = 30
}
}
Other tools to check out:
- Gremlin, Litmus, Chaos Mesh for chaos engineering
- Runbooks and incident templates to stay consistent under pressure
- SLO dashboards to see trouble before it spreads
Final Thought: Don’t Wait for the Flames
Tech moves fast. Systems grow messy. And let’s face it—incidents will happen.
But reacting after the fire isn’t enough. Not anymore. Resilience isn’t a nice-to-have. It’s the foundation.
Pre-mortems won’t stop every failure. But they’ll change the game:
- You plan smarter.
- You catch cracks early.
- You lead with confidence.
Because failure is always just one bad deploy away.
Run pre-mortems. Build chaos docs. Stress-test now—not after the outage.
You’ll thank yourself later.