instrumentation-planning

name	instrumentation-planning
description	Plan backend observability using RED + USE + 4 Golden Signals + JTBD
triggers	["what should I measure","what metrics do I need","observability plan","instrumentation strategy","which metrics matter"]
priority	1

Instrumentation Planning

"What job is this telemetry helping someone accomplish?"

Every metric/span should answer a job. If you can't name the job, don't add the telemetry.

Framework Selection

Service Type	Use
HTTP/gRPC APIs	RED (Rate, Errors, Duration)
Resources (pools, memory)	USE (Utilization, Saturation, Errors)
Comprehensive SRE	4 Golden Signals

Prioritization Tiers

Tier	What	Examples
T0: Foundation	Must have	Service tags, HTTP middleware, error tracking, health checks
T1: Performance	Should have	RED per endpoint, DB tracing, external service spans, context propagation
T2: Resources	Should have	USE for pools, memory/GC, queue depth
T3: Business	Nice to have	JTBD tags, user tier, feature flags
T4: Resilience	Nice to have	Circuit breaker state, retry counts, timeouts

JTBD Context

Link observability to user value:

Job	Success	Failure	Friction
"Place order"	Order created <2s	Order error	Retries >0, duration >5s
"Process payment"	Payment success	Declined	Gateway timeout

Anti-Patterns

• Measure everything → Noise, cost, no signal
• High-cardinality labels → User IDs explode storage
• 100% sampling → Unnecessary overhead
• Missing context → Can't debug without job/step

Output

Present prioritized instrumentation plan organized by tier, with specific metrics and implementation order.

References

Load based on need:

• references/methodology/red-methodology.md
• references/methodology/use-methodology.md
• references/methodology/four-golden-signals.md
• references/methodology/jtbd-for-backend.md