profile api

Profile an API endpoint to identify performance bottlenecks and optimization opportunities.

Steps

1. Identify the target endpoint (URL, method, and payload).
2. Analyze the handler code path:
   • Map all database queries executed per request.
   • Identify external API calls and their expected latency.
   • Check for synchronous blocking operations.
   • Look for N+1 query patterns.
3. Measure baseline performance:
   • Send sample requests and measure response time.
   • Check memory allocation during request handling.
   • Identify the slowest operations in the call chain.
4. Check for common performance issues:
   • Missing database indexes for frequently queried columns.
   • Unbounded result sets without pagination.
   • Redundant data fetching (loading full objects when only IDs needed).
   • Missing caching for expensive computations.
   • Large response payloads without compression.
5. Suggest optimizations ranked by expected impact:
   • Add database indexes.
   • Implement caching layer.
   • Batch database queries.
   • Add pagination.
   • Enable response compression.
6. Estimate performance improvement for each suggestion.

Format

Profile:  <endpoint>
Baseline: <response time>ms (P50), ms (P99)

Bottlenecks:
  1. [HIGH] <description> - estimated ms savings
  2. [MEDIUM] <description> - estimated ms savings

Optimizations:
  1. <specific action to take>
  2. <specific action to take>

Expected improvement: % faster response time

Rules

• Profile with realistic data volumes, not empty databases.
• Measure P50, P95, and P99 latencies, not just averages.
• Identify the single biggest bottleneck before suggesting broad optimizations.
• Never suggest premature optimization for endpoints under 100ms.
• Consider read vs write path optimizations separately.