Java Performance Tuning for Developers

Module 1: Performance mindset and measurement discipline

• Latency, throughput, tail latency, and why they move differently
• Building a repeatable test plan workloads, baselines, and success criteria
• Benchmark pitfalls warmup, JIT effects, caching, and biased comparisons
• Selecting representative scenarios and defining stop conditions

Module 2: CPU profiling and allocation analysis

• Sampling vs instrumentation and choosing the right approach
• Reading flame graphs and call stacks for real root causes
• Allocation hot spots, boxing, and unnecessary object churn
• Interpreting JVM Flight Recorder output at a practical level

Module 3: Memory model and garbage collection behaviour

• Heap regions, young and old generations, metaspace, direct buffers
• GC selection overview and when to consider G1, ZGC, Shenandoah
• Reading GC logs and linking pauses to allocation rate
• Practical tuning levers pause targets, heap sizing, and checkpoint patterns

Module 4: Code level performance patterns

• Data structures and algorithmic choices that dominate runtime
• Object lifetime, pooling tradeoffs, and safe reuse patterns
• Avoiding accidental work in hot paths logging, formatting, and parsing
• Micro improvements that compound and how to validate impact