performance-engineer

仓库: charon-fan/agent-playbook
安装量: 366
排名: #6024

安装

npx skills add https://github.com/charon-fan/agent-playbook --skill performance-engineer

Performance Engineer Specialist in analyzing and optimizing application performance, identifying bottlenecks, and implementing efficiency improvements. When This Skill Activates Activates when you: Report performance issues Need performance optimization Mention "slow" or "latency" Want to improve efficiency Performance Analysis Process Phase 1: Identify the Problem Define metrics What's the baseline? What's the target? What's acceptable? Measure current performance

Response time

curl -w "@curl-format.txt" -o /dev/null -s https://example.com/users

Database query time

Add timing logs to queries

Memory usage

Use profiler

Profile the application

Node.js

node --prof app.js

Python

python -m cProfile app.py

Go

go
test
-cpuprofile
=
cpu.prof
Phase 2: Find the Bottleneck
Common bottleneck locations:
Layer
Common Issues
Database
N+1 queries, missing indexes, large result sets
API
Over-fetching, no caching, serial requests
Application
Inefficient algorithms, excessive logging
Frontend
Large bundles, re-renders, no lazy loading
Network
Too many requests, large payloads, no compression
Phase 3: Optimize
Database Optimization
N+1 Queries:
// Bad: N+1 queries
const
users
=
await
User
.
findAll
(
)
;
for
(
const
user
of
users
)
{
user
.
posts
=
await
Post
.
findAll
(
{
where
:
{
userId
:
user
.
id
}
}
)
;
}
// Good: Eager loading
const
users
=
await
User
.
findAll
(
{
include
:
[
{
model
:
Post
,
as
:
'posts'
}
]
}
)
;
Missing Indexes:
-- Add index on frequently queried columns
CREATE
INDEX
idx_user_email
ON
users
(
email
)
;
CREATE
INDEX
idx_post_user_id
ON
posts
(
user_id
)
;
API Optimization
Pagination:
// Always paginate large result sets
const
users
=
await
User
.
findAll
(
{
limit
:
100
,
offset
:
page
*
100
}
)
;
Field Selection:
// Select only needed fields
const
users
=
await
User
.
findAll
(
{
attributes
:
[
'id'
,
'name'
,
'email'
]
}
)
;
Compression:
// Enable gzip compression
app
.
use
(
compression
(
)
)
;
Frontend Optimization
Code Splitting:
// Lazy load routes
const
Dashboard
=
lazy
(
(
)
=>
import
(
'./Dashboard'
)
)
;
Memoization:
// Use useMemo for expensive calculations
const
filtered
=
useMemo
(
(
)
=>
items
.
filter
(
item
=>
item
.
active
)
,
[
items
]
)
;
Image Optimization:
Use WebP format
Lazy load images
Use responsive images
Compress images
Phase 4: Verify
Measure again
Compare to baseline
Ensure no regressions
Document the improvement
Performance Targets
Metric
Target
Critical Threshold
API Response (p50)
< 100ms
< 500ms
API Response (p95)
< 500ms
< 1s
API Response (p99)
< 1s
< 2s
Database Query
< 50ms
< 200ms
Page Load (FMP)
< 2s
< 3s
Time to Interactive
< 3s
< 5s
Memory Usage
< 512MB
< 1GB
Common Optimizations
Caching Strategy
// Cache expensive computations
const
cache
=
new
Map
(
)
;
async
function
getUserStats
(
userId
:
string
)
{
if
(
cache
.
has
(
userId
)
)
{
return
cache
.
get
(
userId
)
;
}
const
stats
=
await
calculateUserStats
(
userId
)
;
cache
.
set
(
userId
,
stats
)
;
// Invalidate after 5 minutes
setTimeout
(
(
)
=>
cache
.
delete
(
userId
)
,
5
*
60
*
1000
)
;
return
stats
;
}
Batch Processing
// Bad: Individual requests
for
(
const
id
of
userIds
)
{
await
fetchUser
(
id
)
;
}
// Good: Batch request
await
fetchUsers
(
userIds
)
;
Debouncing/Throttling
// Debounce search input
const
debouncedSearch
=
debounce
(
search
,
300
)
;
// Throttle scroll events
const
throttledScroll
=
throttle
(
handleScroll
,
100
)
;
Performance Monitoring
Key Metrics
Response Time
Time to process request
Throughput
Requests per second
Error Rate
Failed requests percentage
Memory Usage
Heap/RAM used
CPU Usage
Processor utilization Monitoring Tools Tool Purpose Lighthouse Frontend performance New Relic APM monitoring Datadog Infrastructure monitoring Prometheus Metrics collection Scripts Profile application: python scripts/profile.py Generate performance report: python scripts/perf_report.py References references/optimization.md - Optimization techniques references/monitoring.md - Monitoring setup references/checklist.md - Performance checklist
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