Do I need performance testing for public APIs?

Usually yes—if your API is public, performance testing is generally worth doing.

Why it matters

Public APIs are exposed to:

• Unknown traffic patterns
• Burst usage
• Abuse or accidental overload
• External clients you don’t control
• SLA / reliability expectations

Performance testing helps you verify:

• Latency under normal and peak load
• Throughput limits
• Scalability as traffic grows
• Stability during spikes
• Failure behavior when dependencies slow down or fail

When it’s especially important

You should strongly consider it if your API:

• Has paid customers or external consumers
• Powers mobile/web apps with user-facing latency concerns
• Supports critical workflows like payments, auth, order processing
• Is expected to handle bursty events or seasonal spikes
• Has rate limits, caching, queues, or other capacity-sensitive behavior

What kind of testing

For public APIs, common performance tests include:

• Load testing: expected traffic
• Stress testing: beyond expected traffic
• Spike testing: sudden bursts
• Soak testing: sustained traffic over time
• Capacity testing: find max safe throughput

If you’re early-stage

Even if you don’t do a full test suite, at least benchmark:

• key endpoints
• database-heavy operations
• authentication/token flows
• third-party integration paths

Practical rule of thumb

If the API is:

• public
• business-critical
• or expected to scale

then performance testing is not optional in practice—it’s part of making it reliable.

If you want, I can give you a minimal performance testing checklist for public APIs.