Java
Deep dive into Java — JVM internals, language evolution, core concepts, concurrency, and design patterns
JVM ArchitectureClassLoader, runtime data areas (heap/stack/metaspace), execution engine, JIT compiler›Java EvolutionMajor features introduced in Java 5, 8, 11, 17, and 21›Core JavaData types, OOP pillars, interfaces vs abstract classes, generics, exception handling, enums›Collections FrameworkList, Set, Map, Queue — implementations, trade-offs, and iteration patterns›Functional ProgrammingLambdas, method references, functional interfaces, Stream API, Optional›ConcurrencyThreads, synchronized, locks, ExecutorService, CompletableFuture, virtual threads›Garbage CollectionGC roots, Serial, Parallel, G1, ZGC, Shenandoah — when to use which›Design Patterns in JavaCreational, structural, and behavioural patterns with Java code examples›Best PracticesEffective Java highlights, SOLID in Java, common pitfalls and anti-patterns›