Performance
5 articles
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Memory Leaks: How to Catch the Bug That Only Shows Up After an Hour
The app works perfectly for five minutes and crashes after an hour. A classic memory leak that no short test case catches. We cover what a leak looks like from the QA side, which scenarios expose it, how to measure memory on Android, iOS, Unity and the web, and what to attach to a bug report so a developer finds the cause in an hour, not a week. With a checklist.
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k6 vs JMeter vs Gatling vs Locust: Which Load Testing Tool to Pick in 2026
The four main load testing tools compared — load model, language, protocols, CI, reporting and price. A selection matrix, what fits which job, and the pitfalls that matter more than the tool itself.
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"It shows me old data" — how to test caches, the quietest source of bugs
The "user sees stale data" bug doesn't reproduce, gets closed as "went away on its own" — and comes back a week later. That's not mysticism, that's a cache. A first-person take: the map of six caching layers (browser, CDN, gateway, application, database, mobile client), invalidation as the main test case, caches leaking other users' data, cache stampede after a deploy, the "every case twice — cold and warm" rule, and why testing with the cache off means testing a system that doesn't exist.
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Load testing: how to design it and not get garbage numbers
How to do load tests right: types (load/stress/soak/spike/breakpoint), percentiles instead of the average, open vs closed model, realistic data and traffic profile, server-side metrics and saturation, coordinated omission, tools k6/Gatling/Locust/JMeter. A 12-point checklist.
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Performance testing for a mobile game: 7 metrics that actually matter
'The game lags' is too abstract for a ticket. To make a performance problem reproducible, measurable and trackable — you need concrete numbers. Here are 7 metrics worth checking every release.