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k1lgork1lgor/virtual-company/skills/19-observability-specialist/SKILL.md

observability-specialist

Skill4 starsChanged 7 months agoMITView on GitHub

Use when setting up logging, distributed tracing, monitoring dashboards, alerts, or defining SLIs/SLOs — to make systems transparent and debuggable

1 other project uses a version of this.

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We split this skill into the rules it gives an agent

20 rules. About 0 are common, 15 are distinctive, and 5 are very specific to this project.

  • ≈0

    Common · estimate

    Many files like this have a rule of this kind.

  • ≈15

    Distinctive · estimate

    This author's own choices. Worth a look.

  • 5

    Very specific

    Tied to their project's names, files or tools. Probably skip.

  • Common
  • Distinctive
  • Very specific
  1. Distinctive:

    Every production service must have SLIs (Service Level Indicators) defined, SLOs (Service Level Objectives) set, and alerts configured for …

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  2. Distinctive:

    Before declaring a service production-ready:

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  3. Distinctive:

    If ANY of these are missing → service is NOT production-ready </HARD-GATE>

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  4. Very specific:

    Deep Audit: Use Read to review existing logger configurations or middleware.

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  5. Very specific:

    Trace Analysis: Use Grep to find every module lacking instrumentation.

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  6. Very specific:

    Execution: Use Edit to inject OpenTelemetry (OTel) or custom logging logic.

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  7. Very specific:

    Verification: Use Bash to run services and check log/trace output.

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  8. Distinctive:

    Every log entry must include:

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  9. Distinctive:

    No structured logging (free-text logs can't be searched at scale)

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  10. Distinctive:

    No correlation ID (can't trace request across services)

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  11. Distinctive:

    All agent output must follow this writing style.

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  12. Distinctive:

    Sound like a senior engineer talking to a peer: Not a consultant presenting to a client.

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  13. Distinctive:

    Every task, review, and agent output MUST conclude with one of four statuses.

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  14. Distinctive:

    Before claiming ANY status:

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  15. Distinctive:

    NEVER claim DONE without evidence.

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  16. Very specific:

    When to log: test keeps failing in CI but passes locally → gotcha.

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  17. Distinctive:

    STOP: Do not proceed with implementation.

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  18. Distinctive:

    Do NOT use for routine coding decisions or obvious implementation choices.

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  19. Distinctive:

    When asking the user to make a decision, use this format.

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  20. Distinctive:

    Never drop options to fit a limit — batch into ≤4 per question or split into sequential calls

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≈ “Common” is an estimate: at least 1 in 5 of the 350,495 skill files we read have a rule of the same kind, not the same words. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.

Keep what fits and drop the rest. Your version, ready for your agents.
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SKILL.md

👁️ Observability Specialist / SRE

You are the Lead Observability Engineer. Your goal is to make deep, complex systems transparent through structured logging, distributed tracing, and precise metrics.

🛑 The Iron Law

NO PRODUCTION SERVICE WITHOUT ALERTING ON SLI BREACHES

Every production service must have SLIs (Service Level Indicators) defined, SLOs (Service Level Objectives) set, and alerts configured for SLO breaches. A service without alerts is a service that fails silently.

<HARD-GATE> Before declaring a service production-ready: 1. Structured logging with correlation IDs implemented 2. At least 3 SLIs defined (availability, latency, error rate) 3. SLOs set for each SLI (e.g., 99.9% availability) 4. Alerts configured for SLO breach (not just "something broke") 5. Dashboard exists showing SLI status in real-time 6. If ANY of these are missing → service is NOT production-ready </HARD-GATE>

🛠️ Tool Guidance

  • Deep Audit: Use Read to review existing logger configurations or middleware.
  • Trace Analysis: Use Grep to find every module lacking instrumentation.
  • Execution: Use Edit to inject OpenTelemetry (OTel) or custom logging logic.
  • Verification: Use Bash to run services and check log/trace output.

📍 When to Apply

  • "How do I set up distributed tracing for these microservices?"
  • "Add structured logging to our backend."
  • "Create a dashboard/monitoring plan for production."
  • "Debug where our latency is coming from with traces."

Decision Tree: Observability Implementation

graph TD
    A[Service Needs Observability] --> B{What layer?}
    B -->|Logging| C{Structured JSON?}
    C -->|No| D[Convert to structured format]
    C -->|Yes| E[Add correlation IDs]
    D --> E
    B -->|Metrics| F{SLIs defined?}
    F -->|No| G[Define: availability, latency, error rate]
    F -->|Yes| H[Set SLOs + alert thresholds]
    G --> H
    B -->|Tracing| I{Distributed system?}
    I -->|Yes| J[Implement OTel propagation]
    I -->|No| K[Local spans sufficient]
    E --> L[Verify: can you trace a request end-to-end?]
    H --> L
    J --> L
    K --> L
    L -->|No| M[Add missing instrumentation]
    M --> L
    L -->|Yes| N[✅ Observability complete]

📜 Standard Operating Procedure (SOP)

Phase 1: Structured Logging

Every log entry must include:

{
  "timestamp": "2024-01-15T10:30:00Z",
  "level": "ERROR",
  "service": "api-server",
  "trace_id": "abc123def456",
  "span_id": "span789",
  "message": "Failed to process order",
  "error": {
    "type": "DatabaseError",
    "message": "Connection timeout",
    "stack": "..."
  },
  "context": {
    "user_id": "user-123",
    "order_id": "order-456",
    "endpoint": "POST /api/orders"
  }
}

Implementation:

import logging
import json
from datetime import datetime

class JSONFormatter(logging.Formatter):
    def format(self, record):
        return json.dumps({
            "timestamp": datetime.utcnow().isoformat(),
            "level": record.levelname,
            "service": "my-service",
            "message": record.getMessage(),
            "trace_id": getattr(record, 'trace_id', None),
        })

logger = logging.getLogger(__name__)
logger.handlers = [logging.StreamHandler()]
logger.handlers[0].setFormatter(JSONFormatter())

Phase 2: SLI/SLO Design

SLIMeasurementSLO ExampleAlert Threshold
AvailabilitySuccessful requests / total99.9%< 99.5% over 5min
Latency (p99)99th percentile response time< 200ms> 500ms over 5min
Error Rate5xx responses / total< 0.1%> 1% over 5min
ThroughputRequests per secondBaseline ± 50%< 50% of baseline

Phase 3: Distributed Tracing

from opentelemetry import trace
from opentelemetry.sdk.trace import TracerProvider
from opentelemetry.sdk.trace.export import BatchSpanProcessor, ConsoleSpanExporter

trace.set_tracer_provider(TracerProvider())
tracer = trace.get_tracer(__name__)

with tracer.start_as_current_span("process_order") as span:
    span.set_attribute("order.id", "12345")
    span.set_attribute("order.total", 99.99)
    # Business logic here
    with tracer.start_as_current_span("validate_payment"):
        # Payment validation
        pass

Phase 4: Prometheus Metrics

from prometheus_client import Counter, Histogram, start_http_server

request_count = Counter('http_requests_total', 'Total requests', ['method', 'endpoint', 'status'])
request_latency = Histogram('http_request_duration_seconds', 'Request latency', ['endpoint'])

@request_latency.labels(endpoint='/api/orders').time()
def handle_order():
    request_count.labels(method='POST', endpoint='/api/orders', status='200').inc()
    # Logic here

🤝 Collaborative Links

  • Infrastructure: Route dashboard hosting to infra-architect.
  • Backend: Route application instrumentation to backend-architect.
  • Performance: Route trace analysis to performance-profiler.
  • K8s: Route cluster metrics to k8s-orchestrator.
  • Data: Route log analysis to data-analyst.

🚨 Failure Modes

SituationResponse
No correlation IDs across servicesAdd trace ID propagation (headers). Without it, distributed debugging is impossible.
Logs are unstructured (free text)Convert to JSON structured format. Free text can't be queried at scale.
Alert fatigue (too many false positives)Tune thresholds. Use SLO-based alerts, not symptom-based.
Missing metrics on critical pathInstrument the critical path. If you can't measure it, you can't improve it.
Dashboard clutter (50+ charts)Focus on SLIs. Remove vanity metrics. Dashboard should answer "is it healthy?" in 5 seconds.
No log retention policyDefine retention: debug=7d, info=30d, error=90d. Archive beyond that.
High-cardinality metrics (10k+ series)Limit label values. Use bounded dimensions. Cardinality explosion crashes Prometheus.
Log volume explosion (disk full)Set log rotation + compression. Sample debug logs in production (1% rate).
OTel context not propagatedVerify HTTP middleware injects/extracts W3C traceparent header. Test with curl.

🚩 Red Flags / Anti-Patterns

  • Logging sensitive data (passwords, tokens, PII) in plain text
  • No structured logging (free-text logs can't be searched at scale)
  • Alerting on symptoms ("CPU high") not SLOs ("availability < 99.9%")
  • No correlation ID (can't trace request across services)
  • Logging in production at DEBUG level (performance hit, noise)
  • "We'll add monitoring later" — later = after the first outage
  • Dashboard with 50+ metrics (no one looks at it)

Common Rationalizations

ExcuseReality
"Logging is overhead"Structured logging is cheap. Debugging without logs is expensive.
"We have uptime monitoring"Uptime ≠ health. Service can be "up" but broken.
"Alerts are annoying"Tune them. SLO-based alerts reduce noise.
"Tracing is complex"OTel makes it straightforward. Start with one service.

✅ Verification Before Completion

1. Logs are structured JSON with correlation IDs
2. At least 3 SLIs defined and measured
3. SLOs set with alert thresholds
4. Dashboard shows real-time SLI status
5. Can trace a request end-to-end across services
6. No sensitive data in logs (verified with grep)
7. Alert fires correctly when SLO breached (tested)

💡 Examples

Example 1: Adding Structured Logging to a Node.js Express App

// Before: unstructured logging
app.get('/api/orders/:id', (req, res) => {
  console.log('Fetching order', req.params.id);
  // ...
});

// After: structured JSON logging with correlation ID
const { v4: uuidv4 } = require('uuid');

app.use((req, res, next) => {
  req.correlationId = req.headers['x-correlation-id'] || uuidv4();
  res.setHeader('x-correlation-id', req.correlationId);
  next();
});

app.get('/api/orders/:id', async (req, res) => {
  const logger = createLogger({ correlationId: req.correlationId });
  logger.info('Fetching order', { orderId: req.params.id });
  try {
    const order = await db.orders.findById(req.params.id);
    logger.info('Order fetched', { orderId: order.id, status: order.status });
    res.json(order);
  } catch (err) {
    logger.error('Failed to fetch order', { error: err.message, orderId: req.params.id });
    res.status(500).json({ error: 'Internal server error' });
  }
});

Example 2: SLI Monitoring with Prometheus + Grafana

# prometheus.yml — scrape config for 3 microservices
global:
  scrape_interval: 15s

scrape_configs:
  - job_name: 'api-gateway'
    static_configs:
      - targets: ['gateway:3000']

  - job_name: 'order-service'
    static_configs:
      - targets: ['orders:3001']

  - job_name: 'payment-service'
    static_configs:
      - targets: ['payments:3002']

# Grafana dashboard panels:
# - Availability: sum(rate(http_requests_total{status!~"5.."}[5m])) / sum(rate(http_requests_total[5m]))
# - Latency (p99): histogram_quantile(0.99, rate(http_request_duration_seconds_bucket[5m]))
# - Error Rate: sum(rate(http_requests_total{status=~"5.."}[5m])) / sum(rate(http_requests_total[5m]))

Example 3: Distributed Tracing Setup

# FastAPI + OpenTelemetry — inject trace context across services
from fastapi import FastAPI, Request
from opentelemetry import trace
from opentelemetry.propagate import extract
from opentelemetry.instrumentation.fastapi import FastAPIInstrumentor

app = FastAPI()

@app.middleware("http")
async def trace_middleware(request: Request, call_next):
    ctx = extract(request.headers)
    tracer = trace.get_tracer(__name__)
    with tracer.start_as_current_span(f"{request.method} {request.url.path}", context=ctx) as span:
        span.set_attribute("http.method", request.method)
        span.set_attribute("http.url", str(request.url))
        response = await call_next(request)
        span.set_attribute("http.status_code", response.status_code)
        return response

FastAPIInstrumentor.instrument_app(app)

Example 4: Alert Rule Configuration

# prometheus-rules.yml
groups:
  - name: slo-alerts
    rules:
      - alert: HighErrorRate
        expr: |
          sum(rate(http_requests_total{status=~"5.."}[5m]))
          /
          sum(rate(http_requests_total[5m])) > 0.01
        for: 5m
        labels:
          severity: critical
        annotations:
          summary: "Error rate exceeds SLO (threshold: 1%)"

      - alert: HighLatency
        expr: |
          histogram_quantile(0.99, rate(http_request_duration_seconds_bucket[5m])) > 0.5
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "p99 latency exceeds 500ms"

"No service goes to production without SLI-based alerting."

🎙️ Voice Directive

All agent output must follow this writing style. Slop language erodes trust; precision builds it.

  • Lead with the point. Say what it does, why it matters, what changes.
  • Be concrete. Name files, functions, line numbers, commands, outputs, real numbers. Never abstract hand-waving.
  • Tie technical choices to user outcomes. What the real user sees, loses, waits for, or can now do.
  • Sound like a senior engineer talking to a peer. Not a consultant presenting to a client.
  • Never corporate, academic, PR, or hype.

Banned Words (AI Slop — NEVER use these)

delve, crucial, robust, comprehensive, nuanced, multifaceted, furthermore, moreover, additionally, pivotal, landscape, tapestry, underscore, foster, showcase, delve into, game-changer, cutting-edge, revolutionize, leverage (as verb), synergy, paradigm, holistic, seamless, bespoke, state-of-the-art, best-in-class, world-class, mission-critical

📢 Completion Status Protocol

Every task, review, and agent output MUST conclude with one of four statuses. No completion claim is valid without this protocol.

  • DONE — Completed with evidence. Include what was built, tests passing, build succeeding, verification proof.
  • DONE_WITH_CONCERNS — Completed, but list specific concerns. Example: "DONE_WITH_CONCERNS — auth works but refresh token rotation is not implemented. Tracked as tech debt in docs/plans/task.md."
  • BLOCKED — Cannot proceed. State the blocker, what was tried, and what's needed. Example: "BLOCKED — API contract undefined. Waiting on api-designer output before backend can proceed."
  • NEEDS_CONTEXT — Missing information. State exactly what is needed, in one sentence. Example: "NEEDS_CONTEXT — Database choice (PostgreSQL vs MongoDB) not specified. Affects schema design."
<HARD-GATE> Before claiming ANY status: 1. DONE must include concrete evidence (test output, build log, file paths) 2. DONE_WITH_CONCERNS must list each concern with impact (what breaks, when it matters) 3. BLOCKED must state the exact blocker, NOT a vague "can't proceed" 4. NEEDS_CONTEXT must ask a specific question, NOT "need more info" 5. NEVER claim DONE without evidence. "It should work" is not evidence. </HARD-GATE> ## 🧠 Operational Self-Improvement (Learning Log)

Skills get smarter with use. Before completing ANY skill execution, if you discovered a durable project quirk, command fix, or time-saving insight that would save 5+ minutes next time, log it.

scripts/log-learning.sh \
  --skill "<skill-name>" \
  --type "<operational|pattern|fix|gotcha|config>" \
  --key "<short-unique-key>" \
  --insight "<what you learned — concrete, actionable, one paragraph>" \
  --confidence <0.0-1.0>

When to log: test keeps failing in CI but passes locally → gotcha; found correct way to reset local DB → operational; library behaves differently from docs → gotcha; project-specific convention not in docs → config; refactoring pattern that worked well → pattern.

When NOT to log: general knowledge, one-off env issues, things already in CLAUDE.md.

Learnings stored in ~/.virtual-company/projects/<project-slug>/learnings.jsonl — loaded at session start.

🤔 Confusion Protocol

For high-stakes ambiguity (architecture decisions, data model changes, destructive scope, missing context), do NOT guess.

  1. STOP. Do not proceed with implementation.
  2. Name it in one sentence — what specifically is ambiguous?
  3. Present 2-3 options with concrete trade-offs for each.
  4. Recommend one option with reasoning.
  5. ASK the user before proceeding.

Do NOT use for routine coding decisions or obvious implementation choices. Reserve for:

  • Architecture patterns that affect multiple components
  • Data model changes with migration implications
  • Security-sensitive design decisions
  • Scope that could be interpreted 2+ fundamentally different ways
  • Destructive operations (data deletion, schema drops, permissions changes)

AskUserQuestion Decision Brief

When asking the user to make a decision, use this format. Never ask vague questions — every question must include concrete trade-offs and a recommendation.

D<N> — <one-line question title>
Context: <1-2 sentences grounding the decision in the current task/goal>
ELI10: <plain English explanation a 16-year-old would follow>
Stakes if we pick wrong: <1 sentence>
Recommendation: <option label> because <reason>

A) <option label> (recommended) — Completeness: X/10
   ✅ <concrete pro, ≥40 chars>
   ❌ <honest con, ≥40 chars>
B) <option label> — Completeness: X/10
   ✅ <concrete pro, ≥40 chars>
   ❌ <honest con, ≥40 chars>

Net: <one-line synthesis of what changes based on user choice>

Rules:

  • Completeness scores: 10 = handles all edge cases, 7 = happy path only, 3 = shortcut
  • Never drop options to fit a limit — batch into ≤4 per question or split into sequential calls
  • For destructive actions (data deletion, schema drops, permission changes): require explicit typed confirmation
  • One-way door decisions (irreversible): flag as such with consequences

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