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APIs slowing down or failing under traffic spikes

High-concurrency API scaling and throughput optimization

Find where an API breaks under load, then fix the bottlenecks: blocking I/O, connection limits, missing caches and missing backpressure.

Symptoms

Signs your platform has this problem

If several of these sound familiar, the plan below is where we would start.

01

Latency spikes under load

Blocking I/O and unpooled database connections exhausting worker threads.

02

502 and 504 errors

Proxies timing out as application worker queues overflow.

03

Lock contention

High write concurrency causing lock waits and deadlocks on hot rows.

Remediation plan

How we fix it, step by step

Each phase ends with a measurement, so you can see what changed before the next one starts.

01

Load testing with k6

Finding the breaking point with load tests that match your real traffic mix.

02

Async request handling

Converting blocking handlers to async I/O, or moving hot paths to a faster service where that pays off.

03

Caching and rate limiting

Serving repeat reads from the CDN and Redis, and limiting abusive clients.

04

Connection pooling

Using RDS Proxy or PgBouncer so many API workers share a small pool of database connections.

Technical checklist

Remediation checklist

What we check before a change goes to production:

  • Load test the API with k6 at and above the expected peak
  • Replace blocking I/O with asynchronous handlers
  • Cache hot reads in Redis with explicit invalidation
  • Add circuit breakers and token-bucket rate limits at the gateway

What we measure

We take a baseline first and report the same measurements after each change, from your own monitoring — evidence, not promised results.

Breaking point
Requests per second before errors rise, from load tests
p99 latency
Under the target load, before and after
Error rate
5xx responses during load tests and real peaks

Related service

Custom software

Custom software for Indian SMEs and startups, built around your workflow with an agreed scope, review milestones, clear ownership and documented handover.

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Questions

Questions about this remediation

We run k6 load tests that ramp traffic sharply — from more than one region where it matters — and watch latency, errors and database load to find the first bottleneck.

Usually caching: serving repeat reads from a CDN and Redis takes load off the backend immediately. How much it helps depends on how cacheable your traffic is, which the load-test traces show.

Want an engineer to look at this with you?

Send us the symptoms and any metrics you have. We'll reply within one business day, set up a call and agree what to measure before anything changes.