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finops-patterns Provides FinOps practices for cloud cost optimization, budget management, and resource rightsizing. Use when analyzing cloud spend, optimizing costs, or when user mentions 'finops', 'cloud cost', 'rightsizing', 'budget', 'cost allocation', 'reserved instance', 'spot instance', 'showback', 'chargeback'.
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Zipをダウンロード ダウンロード中... このリポジトリの他の Skills Use the moment a request is underspecified and you are about to act on an ASSUMED goal. Enumerate the candidate goals the request could mean, project the action or artifact each one implies, and check whether they diverge: if two or more plausible goals lead to materially different actions or artifacts, ask exactly ONE targeted clarifying question; otherwise proceed on the most-likely goal and state the assumption in one line. Clarification is an evidence-producing action, not a delay — but one question, never an interrogation. Distinct from gsd-spec-phase (GSD-phase-bound, emits a heavy SPEC.md) and intent-router (fetch strategy, not goal disambiguation). Backed by agent goal-state inference (arxiv 2606.16813v1). Triggers on acting under an assumed goal when the request admits more than one materially different reading.
Use at write time to vector/embedding memory — Grove content-addressed insertion, chroma/pgvector upserts, memory-consolidation promoting session traces to MEMORY.md, or embedding externally-ingested content. Scores each candidate record against a fixed panel of sentinel queries and quarantines any record that would become the nearest neighbor of too many unrelated queries — a hub — whether from adversarial poisoning or accidental over-generality. This is the memory-record-side sibling of skill-injection-guardian (file-side) and the write-side complement of memory-use-warrant (read-side). Quarantine, never silently drop; a human reviews. Backed by the admission-time hubness gate (arxiv 2606.19692v1). Triggers on inserting into vector memory, consolidating memory, and embedding stranger content.
Run this appropriateness check the moment you are about to integrate a retrieved long-term memory — a Grove content-addressed hit, a chroma/pgvector neighbour, a memory-consolidation digest, or a MEMORY.md line — into a response, especially anything touching private origins, Fox Companies IP, credentials, or Center Camp / consent-governed content. It answers a question intent-router never asks: not WHAT to fetch or HOW, but WHETHER a correctly-retrieved item should reach output. Relevance is not appropriateness — a perfect similarity match can still be a boundary violation. Default is FAIL-CLOSED: if in-context authorization is uncertain, the memory may inform behaviour but must not be surfaced. Backed by RBI-Eval (arxiv 2606.06055v1). Triggers on surfacing recalled sensitive memory into a response.
name finops-patterns description Provides FinOps practices for cloud cost optimization, budget management, and resource rightsizing. Use when analyzing cloud spend, optimizing costs, or when user mentions 'finops', 'cloud cost', 'rightsizing', 'budget', 'cost allocation', 'reserved instance', 'spot instance', 'showback', 'chargeback'. type skill category patterns status stable origin tibsfox modified false first_seen "2026-02-07T00:00:00.000Z" first_path examples/finops-patterns/SKILL.md superseded_by null
FinOps Patterns
Best practices for managing cloud financial operations -- visibility, optimization, and governance of cloud spend at scale.
Cloud Cost Anatomy
Understanding where cloud money goes is the first step to controlling it.
Total Cloud Spend
|
+-- Compute (60-70%)
| +-- VMs / Instances
| +-- Containers (EKS, GKE, ECS)
| +-- Serverless (Lambda, Cloud Functions)
| +-- GPU / ML Training
|
+-- Storage (15-20%)
| +-- Block (EBS, Persistent Disks)
| +-- Object (S3, GCS, Blob)
| +-- Database (RDS, Cloud SQL, DynamoDB)
|
+-- Network (10-15%)
| +-- Data Transfer (egress is expensive)
| +-- Load Balancers
| +-- CDN
| +-- VPN / Direct Connect
|
+-- Other (5-10%)
+-- Monitoring / Logging
+-- DNS / Certificates
+-- Support Plans
+-- Marketplace
Cost Driver Typical Waste Quick Win Idle instances 20-30% of compute Schedule dev/test shutdown nights + weekends Over-provisioned instances 40-60% of instances Rightsize based on actual CPU/memory usage Unattached storage volumes 5-10% of storage Automated cleanup of orphaned EBS/disks Unused Elastic IPs Small but cumulative Release unattached IPs Old snapshots 10-20% of storage Lifecycle policy with retention limits Cross-region data transfer 5-15% of network Co-locate services in same region
FinOps Maturity Model
Organizations progress through three phases of FinOps practice maturity.
Dimension Crawl Walk Run Visibility Monthly bill review Tagged cost allocation by team Real-time cost dashboards per service Allocation Single account, no tagging Cost centers with basic tags Full showback/chargeback by product line Optimization Ad-hoc rightsizing Quarterly review with recommendations Automated rightsizing and scaling policies Forecasting None Spreadsheet-based projections
ML-based anomaly detection and forecasts
Governance No budgets Account-level budgets Per-team budgets with automated enforcement
Commitment On-demand only Some Reserved Instances Savings Plans + Spot + RI portfolio managed
Culture Central IT pays the bill Engineering aware of costs Engineers own cost as a feature metric
Tooling AWS Console only Cost Explorer + basic reports FinOps platform (Kubecost, CloudHealth, etc.)
Cost Allocation Tagging Strategy Tags are the foundation of cost visibility. Without consistent tagging, cost allocation is impossible.
Required Tag Schema
required_tags:
- key: "team"
description: "Owning team (must match teams registry)"
example: "platform-engineering"
validation: "^[a-z]+-[a-z]+$"
- key: "service"
description: "Service or application name"
example: "payment-api"
validation: "^[a-z]+-[a-z]+(-[a-z]+)?$"
- key: "environment"
description: "Deployment environment"
allowed_values: ["production" , "staging" , "development" , "sandbox" ]
- key: "cost-center"
description: "Finance cost center code"
example: "CC-4200"
validation: "^CC-\\d{4}$"
- key: "data-classification"
description: "Data sensitivity level"
allowed_values: ["public" , "internal" , "confidential" , "restricted" ]
optional_tags:
- key: "project"
description: "Project or initiative code"
- key: "managed-by"
description: "IaC tool managing this resource"
allowed_values: ["terraform" , "pulumi" , "cloudformation" , "manual" ]
- key: "expiry"
description: "Auto-delete date for temporary resources"
format: "YYYY-MM-DD"
Tag Enforcement via AWS SCP {
"Version" : "2012-10-17" ,
"Statement" : [
{
"Sid" : "RequireTagsOnResourceCreation" ,
"Effect" : "Deny" ,
"Action" : [
"ec2:RunInstances" ,
"rds:CreateDBInstance" ,
"s3:CreateBucket" ,
"eks:CreateCluster" ,
"lambda:CreateFunction"
] ,
"Resource" : "*" ,
"Condition" : {
"Null" : {
"aws:RequestTag/team" : "true" ,
"aws:RequestTag/service" : "true" ,
"aws:RequestTag/environment" : "true" ,
"aws:RequestTag/cost-center" : "true"
}
}
}
]
}
Rightsizing Analysis
Instance Rightsizing Script
"""rightsizing.py -- Analyze EC2 instances for rightsizing opportunities."""
import boto3
from datetime import datetime, timedelta, timezone
from dataclasses import dataclass
UTILIZATION_THRESHOLD = 40
LOOKBACK_DAYS = 14
MIN_DATAPOINTS = 100
@dataclass
class RightsizeRecommendation :
instance_id: str
instance_type: str
avg_cpu: float
max_cpu: float
avg_memory: float
recommended_type: str
monthly_savings: float
confidence: str
DOWNSIZE_MAP = {
"m5.2xlarge" : "m5.xlarge" ,
"m5.xlarge" : "m5.large" ,
"m5.large" : "m5.medium" ,
"c5.2xlarge" : "c5.xlarge" ,
"c5.xlarge" : "c5.large" ,
"r5.2xlarge" : "r5.xlarge" ,
"r5.xlarge" : "r5.large" ,
"t3.xlarge" : "t3.large" ,
"t3.large" : "t3.medium" ,
}
HOURLY_PRICING = {
"m5.2xlarge" : 0.384 , "m5.xlarge" : 0.192 , "m5.large" : 0.096 ,
"c5.2xlarge" : 0.340 , "c5.xlarge" : 0.170 , "c5.large" : 0.085 ,
"r5.2xlarge" : 0.504 , "r5.xlarge" : 0.252 , "r5.large" : 0.126 ,
"t3.xlarge" : 0.1664 , "t3.large" : 0.0832 , "t3.medium" : 0.0416 ,
}
def get_cpu_utilization (cw_client, instance_id: str ) -> tuple [float , float ]:
"""Return (avg_cpu, max_cpu) over the lookback period."""
end = datetime.now(timezone.utc)
start = end - timedelta(days=LOOKBACK_DAYS)
response = cw_client.get_metric_statistics(
Namespace="AWS/EC2" ,
MetricName="CPUUtilization" ,
Dimensions=[{"Name" : "InstanceId" , "Value" : instance_id}],
StartTime=start,
EndTime=end,
Period=3600 ,
Statistics=["Average" , "Maximum" ],
)
datapoints = response.get("Datapoints" , [])
if len (datapoints) < MIN_DATAPOINTS:
return -1.0 , -1.0
avg = sum (dp["Average" ] for dp in datapoints) / len (datapoints)
peak = max (dp["Maximum" ] for dp in datapoints)
return avg, peak
def analyze_fleet () -> list [RightsizeRecommendation]:
"""Analyze all running EC2 instances for rightsizing."""
ec2 = boto3.client("ec2" )
cw = boto3.client("cloudwatch" )
recommendations = []
paginator = ec2.get_paginator("describe_instances" )
for page in paginator.paginate(
Filters=[{"Name" : "instance-state-name" , "Values" : ["running" ]}]
):
for reservation in page["Reservations" ]:
for instance in reservation["Instances" ]:
instance_id = instance["InstanceId" ]
instance_type = instance["InstanceType" ]
if instance_type not in DOWNSIZE_MAP:
continue
avg_cpu, max_cpu = get_cpu_utilization(cw, instance_id)
if avg_cpu < 0 :
continue
if avg_cpu < UTILIZATION_THRESHOLD:
recommended = DOWNSIZE_MAP[instance_type]
current_cost = HOURLY_PRICING.get(instance_type, 0 )
new_cost = HOURLY_PRICING.get(recommended, 0 )
monthly_savings = (current_cost - new_cost) * 730
confidence = "high" if max_cpu < 60 else "medium"
recommendations.append(RightsizeRecommendation(
instance_id=instance_id,
instance_type=instance_type,
avg_cpu=round (avg_cpu, 1 ),
max_cpu=round (max_cpu, 1 ),
avg_memory=-1.0 ,
recommended_type=recommended,
monthly_savings=round (monthly_savings, 2 ),
confidence=confidence,
))
recommendations.sort(key=lambda r: r.monthly_savings, reverse=True )
return recommendations
if __name__ == "__main__" :
recs = analyze_fleet()
total_savings = sum (r.monthly_savings for r in recs)
print (f"\n{'=' *80 } " )
print (f"RIGHTSIZING RECOMMENDATIONS ({len (recs)} instances)" )
print (f"Potential monthly savings: ${total_savings:,.2 f} " )
print (f"{'=' *80 } \n" )
for r in recs:
print (f" {r.instance_id} : {r.instance_type} -> {r.recommended_type} " )
print (f" CPU avg={r.avg_cpu} % max={r.max_cpu} %" )
print (f" Savings: ${r.monthly_savings} /mo Confidence: {r.confidence} " )
print ()
Budget Alert Configuration
AWS CloudWatch Budget Alarm
AWSTemplateFormatVersion: "2010-09-09"
Description: FinOps budget alerts with multi-threshold notifications
Parameters:
TeamName:
Type: String
Description: Team name for cost allocation
MonthlyBudget:
Type: Number
Description: Monthly budget in USD
AlertEmail:
Type: String
Description: Email for budget notifications
SlackWebhookArn:
Type: String
Description: ARN of Lambda that posts to Slack
Resources:
BudgetAlertTopic:
Type: AWS::SNS::Topic
Properties:
TopicName: !Sub "${TeamName}-budget-alerts"
Subscription:
- Protocol: email
Endpoint: !Ref AlertEmail
- Protocol: lambda
Endpoint: !Ref SlackWebhookArn
TeamBudget:
Type: AWS::Budgets::Budget
Properties:
Budget:
BudgetName: !Sub "${TeamName}-monthly-budget"
BudgetLimit:
Amount: !Ref MonthlyBudget
Unit: USD
TimeUnit: MONTHLY
BudgetType: COST
CostFilters:
TagKeyValue:
- !Sub "user:team$${TeamName}"
NotificationsWithSubscribers:
- Notification:
NotificationType: ACTUAL
ComparisonOperator: GREATER_THAN
Threshold: 50
ThresholdType: PERCENTAGE
Subscribers:
- SubscriptionType: SNS
Address: !Ref BudgetAlertTopic
- Notification:
NotificationType: ACTUAL
ComparisonOperator: GREATER_THAN
Threshold: 80
ThresholdType: PERCENTAGE
Subscribers:
- SubscriptionType: SNS
Address: !Ref BudgetAlertTopic
- Notification:
NotificationType: ACTUAL
ComparisonOperator: GREATER_THAN
Threshold: 100
ThresholdType: PERCENTAGE
Subscribers:
- SubscriptionType: SNS
Address: !Ref BudgetAlertTopic
- Notification:
NotificationType: FORECASTED
ComparisonOperator: GREATER_THAN
Threshold: 100
ThresholdType: PERCENTAGE
Subscribers:
- SubscriptionType: SNS
Address: !Ref BudgetAlertTopic
DailySpendAlarm:
Type: AWS::CloudWatch::Alarm
Properties:
AlarmName: !Sub "${TeamName}-daily-spend-spike"
AlarmDescription: "Daily spend exceeds expected daily average by 2x"
Namespace: AWS/Billing
MetricName: EstimatedCharges
Dimensions:
- Name: Currency
Value: USD
Statistic: Maximum
Period: 86400
EvaluationPeriods: 1
Threshold: !Sub "${AWS::NoValue}"
ComparisonOperator: GreaterThanThreshold
AlarmActions:
- !Ref BudgetAlertTopic
Spot Instance Handling
Spot Instance Strategy with Fallback
apiVersion: eksctl.io/v1alpha5
kind: ClusterConfig
metadata:
name: production-cluster
region: us-east-1
managedNodeGroups:
- name: baseline-on-demand
instanceType: m5.xlarge
desiredCapacity: 3
minSize: 3
maxSize: 6
labels:
node-type: on-demand
workload-class: critical
taints:
- key: workload-class
value: critical
effect: NoSchedule
- name: spot-workers
instanceTypes:
- m5.xlarge
- m5a.xlarge
- m5d.xlarge
- m4.xlarge
- m5n.xlarge
spot: true
desiredCapacity: 6
minSize: 2
maxSize: 20
labels:
node-type: spot
workload-class: batch
tags:
k8s.io/cluster-autoscaler/enabled: "true"
---
apiVersion: policy/v1
kind: PodDisruptionBudget
metadata:
name: batch-processor-pdb
spec:
minAvailable: 2
selector:
matchLabels:
app: batch-processor
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: batch-processor
spec:
replicas: 6
selector:
matchLabels:
app: batch-processor
template:
metadata:
labels:
app: batch-processor
spec:
affinity:
nodeAffinity:
preferredDuringSchedulingIgnoredDuringExecution:
- weight: 90
preference:
matchExpressions:
- key: node-type
operator: In
values: ["spot" ]
- weight: 10
preference:
matchExpressions:
- key: node-type
operator: In
values: ["on-demand" ]
terminationGracePeriodSeconds: 120
containers:
- name: batch-processor
image: registry.example.com/batch-processor:latest
lifecycle:
preStop:
exec:
command:
- /bin/sh
- -c
- "echo 'Draining...' && /app/drain.sh && sleep 30"
Cost Anomaly Detection
Automated Anomaly Detection Script
"""cost-anomaly.py -- Detect unusual spending patterns using AWS Cost Explorer."""
import boto3
import json
from datetime import datetime, timedelta
from dataclasses import dataclass
ANOMALY_THRESHOLD = 1.5
LOOKBACK_DAYS = 30
MINIMUM_DAILY_COST = 10.0
@dataclass
class CostAnomaly :
service: str
date: str
actual_cost: float
expected_cost: float
deviation_pct: float
severity: str
def get_daily_costs (ce_client, days: int ) -> dict [str , list [float ]]:
"""Fetch daily costs by service for the past N days."""
end = datetime.utcnow().date()
start = end - timedelta(days=days)
response = ce_client.get_cost_and_usage(
TimePeriod={
"Start" : start.isoformat(),
"End" : end.isoformat(),
},
Granularity="DAILY" ,
Metrics=["UnblendedCost" ],
GroupBy=[
{"Type" : "DIMENSION" , "Key" : "SERVICE" },
],
)
service_costs: dict [str , list [float ]] = {}
for result in response["ResultsByTime" ]:
for group in result["Groups" ]:
service = group["Keys" ][0 ]
cost = float (group["Metrics" ]["UnblendedCost" ]["Amount" ])
if service not in service_costs:
service_costs[service] = []
service_costs[service].append(cost)
return service_costs
def detect_anomalies (service_costs: dict [str , list [float ]] ) -> list [CostAnomaly]:
"""Detect cost anomalies using rolling average comparison."""
anomalies = []
for service, costs in service_costs.items():
if len (costs) < 7 :
continue
baseline = costs[:-1 ]
latest = costs[-1 ]
avg_cost = sum (baseline) / len (baseline)
if avg_cost < MINIMUM_DAILY_COST:
continue
if avg_cost == 0 :
continue
deviation = latest / avg_cost
if deviation >= ANOMALY_THRESHOLD:
deviation_pct = (deviation - 1 ) * 100
severity = "critical" if deviation >= 2.0 else "warning"
anomalies.append(CostAnomaly(
service=service,
date=datetime.utcnow().date().isoformat(),
actual_cost=round (latest, 2 ),
expected_cost=round (avg_cost, 2 ),
deviation_pct=round (deviation_pct, 1 ),
severity=severity,
))
anomalies.sort(key=lambda a: a.deviation_pct, reverse=True )
return anomalies
def send_alert (anomalies: list [CostAnomaly] ) -> None :
"""Send anomaly alerts via SNS."""
if not anomalies:
return
sns = boto3.client("sns" )
topic_arn = "arn:aws:sns:us-east-1:123456789:finops-alerts"
total_excess = sum (a.actual_cost - a.expected_cost for a in anomalies)
message_lines = [
f"COST ANOMALY ALERT -- {len (anomalies)} services affected" ,
f"Estimated excess spend today: ${total_excess:,.2 f} " ,
"" ,
]
for a in anomalies:
message_lines.append(
f" [{a.severity.upper()} ] {a.service} : "
f"${a.actual_cost} (expected ${a.expected_cost} , "
f"+{a.deviation_pct} %)"
)
sns.publish(
TopicArn=topic_arn,
Subject=f"FinOps Alert: {len (anomalies)} cost anomalies detected" ,
Message="\n" .join(message_lines),
)
if __name__ == "__main__" :
ce = boto3.client("ce" )
costs = get_daily_costs(ce, LOOKBACK_DAYS)
anomalies = detect_anomalies(costs)
if anomalies:
print (f"\nDETECTED {len (anomalies)} ANOMALIES:\n" )
for a in anomalies:
print (f" [{a.severity} ] {a.service} " )
print (f" Today: ${a.actual_cost} Avg: ${a.expected_cost} "
f"Deviation: +{a.deviation_pct} %" )
print ()
send_alert(anomalies)
else :
print ("No cost anomalies detected." )
Showback vs Chargeback Models Aspect Showback Chargeback Definition Report costs to teams for visibility Bill costs back to team budgets Financial impact Informational only Deducted from team budget Accountability Soft (awareness) Hard (budget ownership) Implementation complexity Low High (needs finance integration) Cultural resistance Low Medium-High Best for FinOps Crawl/Walk maturity FinOps Run maturity Shared costs Shown but not allocated Must be allocated (often contentious)
Shared Cost Allocation Methods Method How it Works Best For Even split Divide equally among teams Simple, low contention Proportional (usage) Allocate by % of usage metrics Fair but needs good metrics Proportional (headcount) Allocate by team size Easy, rough approximation Fixed ratio Pre-agreed percentages Stable, predictable Tag-based Allocate by tagged resource ownership Most accurate, needs tagging discipline
FinOps Team Structure and RACI Activity FinOps Lead Engineering Finance Management Set budget targets C I A R Tag resources I R - A Review cost reports R C C I Approve Reserved Instances C C A R Implement rightsizing C R I A Anomaly investigation A R I C Negotiate cloud contracts R C A I Build cost dashboards R C I I Enforce tagging policy A R - I Quarterly cost review R C C A
R = Responsible, A = Accountable, C = Consulted, I = Informed
Commitment Strategy: Reserved vs Spot vs On-Demand Purchase Model Discount Commitment Flexibility Best For On-Demand 0% None Full Unpredictable workloads, spikes Savings Plans (Compute) 30-40% 1 or 3 year High (any instance type) Steady-state baseline Savings Plans (Instance) 40-50% 1 or 3 year Medium (one family) Known instance families Reserved Instances 40-60% 1 or 3 year Low (specific type) Databases, fixed workloads Spot Instances 60-90% None None (can be reclaimed) Batch, CI/CD, fault-tolerant
Portfolio Strategy Total compute spend = 100%
Committed (Savings Plans / RI): 60-70%
-- Covers steady-state baseline that runs 24/7
-- Buy based on minimum observed usage over 3 months
On-Demand: 10-20%
-- Covers variable load above baseline
-- Handles unpredictable spikes
Spot: 10-20%
-- Batch processing, CI/CD runners, dev/test
-- Workloads that tolerate interruption
Anti-Patterns Anti-Pattern Problem Fix No tagging strategy Cannot allocate costs to teams or services Enforce required tags via SCP; deny untagged resource creation Single payer, no visibility Teams have no cost awareness Implement showback reports; per-team dashboards Over-buying Reserved Instances Locked into unused capacity Start with Compute Savings Plans; buy RI only for stable workloads Ignoring data transfer costs Network egress surprises on the bill Architect for same-region; use VPC endpoints; monitor egress No budget alerts Overspend discovered at month-end Set progressive alerts at 50%, 80%, 100% of budget Dev/test runs 24/7 Paying for resources nobody uses nights/weekends Schedule auto-stop; 65% savings for 10hr/day schedule Orphaned resources EBS volumes, IPs, snapshots accumulate after instances deleted Automated weekly cleanup of unattached resources Rightsizing by gut feel Wrong instance types selected without data Use CloudWatch metrics; require 2+ weeks data before resizing No commitment strategy Paying full on-demand price for steady workloads Analyze usage baseline; buy Savings Plans for committed floor Cost optimization as one-time project Savings erode as teams spin up new resources Continuous FinOps practice; monthly reviews; automated policies Shared account with no allocation Impossible to attribute costs Separate accounts per team/environment; use AWS Organizations Ignoring storage lifecycle Hot-tier pricing for cold data S3 lifecycle policies; archive to Glacier after 90 days No unit economics Cannot correlate cost to business value Track cost-per-transaction, cost-per-user, cost-per-API-call
FinOps Implementation Checklist
Phase 1: Crawl (Visibility)
Phase 2: Walk (Optimization)
Phase 3: Run (Governance) 