#30DaysOfJava

Day 28 of #30DaysOfJava — week 4 done ✅ covered this week: → Concurrency — locks, deadlocks, tools → Java Memory Model — happens-before → CompletableFuture — async done right → Microservices Patterns — circuit breaker, saga → Performance Tuning — N+1, GC, profiling → Java 17+ — records, virtual threads week 5 starts tomorrow #Java #30DaysOfJava

starting #30DaysOfJava today not tutorials not "top 10 tips" actual internals — how Java works under the code you write daily HashMap, JVM, GC, threads, Spring, concurrency and more one concept. every day. let's go

starting #30DaysOfJava today not tutorials not "top 10 tips" actual internals — how Java works under the code you write daily HashMap, JVM, GC, threads, Spring, concurrency and more one concept. every day. let's go 🧵 #Java #SoftwareEngineering

Day 27 of #30DaysOfJava Java 17+ features still writing Java 8 code in 2026? java has evolved dramatically features that make code cleaner, safer, faster and most teams aren't using them yet #Java #30DaysOfJava

🧵 Day 24/30 – Java Stream API (Advanced) 🔥 Today I dived deep into: ✅ map() vs flatMap() ✅ Collectors: toList(), groupingBy(), partitioningBy() ✅ reduce() for aggregation ✅ Sorting, short-circuiting & parallel streams #Java #30DaysOfJava #LearnInPublic

Day 10 of #30DaysOfJava Stack vs Heap every Java developer says they know this very few can explain what actually lives where and why let's fix that 🧵 #Java #30DaysOfJava

🧵 Day 4 – Deep Dive into Loops (Part 2): while, do-while, nested loops & loop control Mastering the art of repetition & control in Java: ✔️ while, do-while loops ✔️ Nested loops (patterns, triangles) ✔️ break & continue #30DaysOfJava #LearnInPublic #Java #CodeNewbie 👇

Day 21 of #30DaysOfJava — week 3 done ✅ covered this week: → Exception Handling — hierarchy + mistakes → Collections — right tool, right job → Stream API — lazy evaluation internals → Functional Interfaces — lambdas underneath → Design Patterns — patterns you already use → Spring Boot — startup to first request week 4 starts tomorrow 🧵 #Java #30DaysOfJava

Day 20 of #30DaysOfJava — Spring Boot every Java backend dev uses Spring Boot very few know what happens between application startup and first request handled it's not magic it's a very clever framework 🧵 #Java #30DaysOfJava

HashSet internally: backed by a HashMap your element = key value = a dummy object (PRESENT) add("hello") actually does: map.put("hello", PRESENT) uniqueness? same as HashMap key uniqueness hashCode() + equals() that's it no magic just HashMap underneath #Java #30DaysOfJava

Day 2 of #30DaysOfJava — HashSet most devs think HashSet is just "a list without duplicates" it's not it's a HashMap wearing a disguise 🧵 #Java #30DaysOfJava

🚀 Day 9 of #30DaysOfJava Topics I covered today 👇 🔹 polymorphism 🔹 abstraction 🔹 encapsulation 🔹 abstract , interface Let’s break it down 🧵 #Coding #LearnInPublic #Java

🧵 Day 21/30 – Java Multithreading Deep Dive ☕ Thread.sleep(): Pause threads ☕ join(): Wait for other thread to finish ⚠️ Race Conditions = data chaos 🔐 synchronized = thread-safe access 💡 Avoid deadlocks & use thread pools! #Java #30DaysOfJava #LearnInPublic

Day 30 of #30DaysOfJava ✅ 30 days. 30 concepts. done. 💪 what we covered: Week 1 → Collections internals Week 2 → JVM, GC, Threads Week 3 → Streams, Patterns, Spring Boot Week 4 → Concurrency, CompletableFuture, Microservices, Performance Day 29 → JPA/Hibernate internals that's Java — from basics to production #Java #30DaysOfJava

🧵Day 1 of 30 – Java from Scratch Let’s begin with the foundations: ➡️ What is Java? ➡️ JVM, JDK, JRE ➡️ History of Java ➡️ OOP Concepts ➡️ Java Program Structure & Syntax #30DaysOfJava #LearnInPublic #Java #CodeNewbie 👇

Day 3 of #30DaysOfJava ArrayList vs LinkedList the interview question everyone gets wrong "use LinkedList when you insert a lot" sounds right is almost always wrong

Day 8 of #30DaysOfJava — JVM you write Java code JVM runs it but what actually happens between those two steps? most developers never look 🧵 #Java #30DaysOfJava

Day 17 of #30DaysOfJava — Stream API streams made Java code beautiful but most devs use them without knowing: → why they're lazy → why order matters → why parallel streams can actually be slower internals time 🧵 #Java #30DaysOfJava

Day 1 of #30DaysOfJava — HashMap most devs use it daily very few know what put() actually does it's not "stores key value" there's a whole path under that one call 🧵 #Java #30DaysOfJava

Day 3 of #30DaysOfJava ArrayList vs LinkedList the interview question everyone gets wrong "use LinkedList when you insert a lot" sounds right is almost always wrong 🧵 #Java #30DaysOfJava