> ## Documentation Index > Fetch the complete documentation index at: https://springbolt.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Explore Topics > Select a topic to dive in. These notes are structured to be read linearly or used as a reference. ## ☕ [Core Java](/docs/core-java) Foundational concepts required for every Java developer. Classes, Objects, Inheritance, Polymorphism, Abstraction, Encapsulation. Try-catch, finally, throw vs throws, custom exceptions. Understanding String immutability, the String Pool, StringBuilder, and StringBuffer. ## 📚 Java Collections Data structures and utilities for managing groups of objects. List, Set, Map, Queue, Deque interfaces and implementations. Type parameters, bounded types, wildcards. Functional programming, map, filter, reduce, collectors. ## 🚀 Advanced Topics In-depth concepts for experienced Java developers. Threads, Synchronization, Executors, Concurrent Collections. Thread Lifecycle, Runnable, Callable, Thread Pools. Heap vs Stack, Object Lifecycle, Memory Leaks. ## 🛠️ Patterns A collection of proven solutions for architecture, enterprise systems, and algorithmic problem solving. Creational, Structural, and Behavioral patterns (Singleton, Factory, Observer). Enterprise architectures like MVC, DAO, DTO, and Front Controller. Interview strategies like Sliding Window, Two Pointers, and Merge Intervals.