Day 3Level 1 — Core Mental Models
Non-Functional Requirements: From Vague to Quantified
Learn: 45 minMap: 30 minDesign: 60 min
Core Concepts (5)
- 1.SLI → SLO → Error Budget is the only language that makes reliability negotiable
- 2.Availability, latency, durability, throughput — each needs an SLI and SLO
- 3.Error budgets turn 'reliability' into a resource you spend on features
- 4.Capacity planning: model peak QPS, storage growth, network egress for 12-18 months
- 5.If you don't have an SLO, you have an implicit one — and it's probably wrong
Map to Your Experience
Does your system have explicit SLOs? If not, what would they be? Calculate the error budget for 99.9% availability over 30 days.
Design Brief: SLO Specification for Your System
Requirements
- •Define at least 4 SLIs with measurable queries
- •Set SLO targets with business justification
- •Calculate error budgets per SLO
- •Model QPS, storage, network growth for 12 months
Constraints
- •Use real or realistic numbers
- •SLOs must be measurable in your observability stack
Must Cover
sli-definitionslo-targetserror-budgetscapacity-model
Trade-off Axis
reliability investment vs feature velocity
Referenced Patterns
Competencies Advanced
reliability ops → L2requirements constraints → L3
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