Performance Testing

Find out how your application behaves under real-world load before your users do. We identify bottlenecks, measure limits, and give you confidence to ship.

Your application works fine - until it doesn't.

A product launch, a breaking news story, an election night, a marketing campaign that goes viral. Traffic spikes are rarely predictable, but they are always consequential. The question is not whether your system will face peak load - it's whether it will handle it gracefully or fall over.

Performance testing answers that question before your users ask it for you. We simulate realistic traffic patterns - from everyday load to extreme spikes - and measure exactly where your system breaks, so you can fix it on your terms, not during an outage.

Normal traffic OK

System responds well within acceptable limits

Peak traffic ?

Latency rises, errors may start appearing

Beyond capacity FAILURE

Timeouts, cascading failures, downtime

We find the exact point where your system transitions from "fine" to "failing" - and tell you precisely what to fix to push that boundary further.

A proven four-phase methodology

We follow industry-standard testing practices, progressively increasing load to paint a complete picture of your system's behavior - from idle to overloaded.

Phase 1

Baseline Test

Establish reference values under minimal load. This gives us a clean measurement of your system's best-case response times and resource consumption - the benchmark everything else is compared against.

Phase 2

Load Test

Simulate your expected day-to-day traffic. We verify that the system meets performance criteria under normal operating conditions and stays stable over sustained periods.

Phase 3

Stress Test

Push well beyond expected peak load to find your system's actual breaking point. We identify which component fails first - the database, the application server, the cache layer - and at what exact threshold.

Phase 4

Spike Test

Simulate a sudden, sharp surge in traffic - the kind caused by a viral post or breaking news. We measure how quickly your system adapts to the spike and how cleanly it recovers afterward.

What we measure

Numbers that matter. We track the key indicators that determine whether your users experience a fast, reliable application - or frustration.

Response Time

Min, max, average, median, and percentiles (P50, P90, P95, P99). Not just averages - we show you the experience your slowest users have.

Throughput

Requests per second your system can sustain. We measure both the comfortable cruising speed and the maximum capacity before degradation.

Error Rate

Percentage of failed requests under each load level. We pinpoint exactly when errors start appearing and what triggers them.

Concurrent Users

How many simultaneous users your system can serve while maintaining acceptable performance. The number that answers "how many is too many?"

Typical success criteria

< 2s

P95 response time

< 1%

Error rate under load

Stable

Throughput over time

Exact thresholds are defined together with you based on your application's requirements and user expectations.

Built on Gatling - an industry-grade testing engine

We use Gatling, a modern open-source load testing framework designed for high throughput and precise reporting. It generates thousands of virtual users from a single machine while consuming minimal resources.

Test scenarios are generated as source code (Scala, Java, or Kotlin) and adjusted as needed. This means your tests are version-controlled, reviewable, and easy to maintain as your application evolves.

Code-based scenarios
Rich HTML reports
Lightweight & scalable
Open source, no license fees
Example of a Gatling performance test report showing response time distribution, throughput, and percentile charts

Beyond the API - we test what your users actually see

Load testing verifies that your backend can handle the traffic. But your users don't interact with APIs - they interact with a UI. A fast server means nothing if the interface is broken, unresponsive, or visually wrong after a deployment.

We use Playwright to automate end-to-end UI testing - verifying that real user workflows work correctly in real browsers. Combined with performance testing, this gives you confidence across the full stack: the API holds up under load, and the interface works as expected.

Standard web applications

Playwright excels at testing conventional DOM-based interfaces - forms, navigation flows, dynamic content, multi-step wizards. We write reliable, maintainable test suites that run in CI and catch regressions before they reach production.

Rare expertise

Canvas-rendered applications

Some applications render their UI entirely on an HTML canvas - there are no DOM elements to query, no selectors to grab. Most testing teams stop here. We don't.

We have hands-on experience testing canvas-rendered interfaces using pixel-level assertions, coordinate-based interactions, visual comparison techniques, and semantic widget tree assertions that verify UI state beyond what pixels alone can tell you. If your app paints to a canvas, we can still automate it.

What you get
1

Ready-to-run test suite

Gatling load simulations with configurable traffic profiles. Optionally paired with Playwright end-to-end UI tests that verify your critical workflows in real browsers - including canvas-rendered interfaces.

2

Detailed performance report

Interactive HTML reports with response time distributions, percentile charts, throughput graphs, and per-request breakdowns.

3

Bottleneck analysis

Expert interpretation of results - which components are the limiting factor, where latency comes from, and what to prioritize.

4

Knowledge transfer

Full documentation and hands-on training so your team can run, modify, and interpret tests independently going forward.

Not just a report - a capability you keep

We don't just test your application and walk away. We build a complete, reusable testing solution that becomes part of your development workflow. Run the same tests before every release, after every infrastructure change, or whenever you need confidence.

Every deliverable is designed for independence. After the engagement, you have everything you need to own your performance testing in-house - the scripts, the know-how, and the documentation.

Fully reusable

Run tests on every release

Your team owns it

Training included

Will your application hold up when it matters most?

Tell us about your application and expected traffic. We'll design a testing approach that answers the questions that matter most to your business.

Email us: info@invisoft.eu