Nitish kumar

Java Developer @TCS (Java, SpringBoot, PostgreSQL, JPA, Hibernate, Rest API, AWS) | Building NitiKart, an eCommerce platform | Problem-solving

[Nitish kumar @nitish_da]

Day 1 🚀
Starting NitiKart – a Spring Boot E-commerce backend project.
Focus: clean architecture, real-world backend practices.

Tech: Java | Spring Boot | PostgreSQL

#JavaDeveloper #backend #buildinpublic #springbootjava

[Nitish kumar @nitish_da]

Just built a URL Shortener with #SpringBoot, #Java, and #PostgreSQL!
🚀 Converting long URLs into short, shareable links. Loved working on the Base62 encoding logic.
Frontend with Tailwind/JS.
#BuildInPublic #springboot #Backend

[Nitish kumar @nitish_da]

Orders module completed in NitiKart ✅
PostgreSQL is fully integrated and the order flow is working end-to-end 🚀
Next up: AWS deployment ☁️
#SpringBoot #JavaBackend #PostgreSQL @✨Learn In Public Bot✨

[Nitish kumar @nitish_da]

🚀 Address Module completed for my Spring Boot eCommerce project NitiKart!
CRUD APIs, user-wise address mapping, validation & exception handling done.
📺 Full demo on YouTube: @CodeNiti8
#SpringBoot #Java #BackendDev #BuildInPublic

[Nitish kumar @nitish_da]

🛒 Cart Module completed for my Spring Boot eCommerce project NitiKart
Add ➕ Update ✏️ Delete ❌ cart items with proper quantity & price handling.
🎥 Full working flow video coming soon on YouTube Code Niti 🚀
#SpringBoot #Java #Backend #LearningInPublic #NitiKart

[Nitish kumar @nitish_da]

🚀 Done Security module -NitiKart
✅ Signup | Login | JWT | Cookies | Secure APIs | Logout
📸 Postman responses + code snippets attached
Yt: https://t.co/chv0SbTMHV
#SpringBoot #Backend #Java #SDE1 #JWT

[Nitish kumar @nitish_da]

Day 13 🚀

Implemented CustomUserDetails & UserDetailsService in my Spring Boot eCommerce project #NitiKart

🔐 DB-backed authentication
🔑 Role-based security foundation
Java | Spring Security | JWT

#BackendDev #SpringBoot #Java #SpringBoot #LearningInPublic

[Nitish kumar @nitish_da]

Day 12 🚀
Completed User, Role & Address models for Spring Security in my Spring Boot e-commerce project (NitiKart).
Next: JWT auth, login/signup & security config 🔐

#SpringBoot #Java #JWT #Backend #LearningInPublic

[Nitish kumar @nitish_da]

✅ DSA Revision – Sliding Window Pattern

Solved LC 567 – Permutation in String
Key concepts:
• Fixed-size sliding window
• Frequency matching
• O(n) time | O(1) space
Revising DSA pattern
#DSA #LeetCode #SlidingWindow #Java #SDE1 #CodingJourney

[Nitish kumar @nitish_da]

@ethanmonkhouse Thanks! Yes, JWT filter really makes the whole security flow clear 🙌

[Nitish kumar @nitish_da]

Day 10 – NitiKart 🚀
Completed JWTUtils for Spring Security.
✔ Generate JWT
✔ Validate token
✔ Extract username

Next: JWT filter & security config 🔐
#Java #SpringBoot #JWT #BuildInPublic

[Nitish kumar @nitish_da]

Day 11 update 🚀
✅ Implemented JWT Filter & AuthEntryPoint
🔜 Next: Security Configuration
#SpringBoot #JWT #SpringSecurity #BackendDev #NitiKart

[Nitish kumar @nitish_da]

✅ Solved LC 424 – Longest Repeating Character Replacement
Sliding Window | Frequency Count | O(n)
Key Insight: windowSize - maxFreq <= k
Continuing DSA revision pattern-wise 🚀
#DSA #LeetCode #SDE1 #Java

[Nitish kumar @nitish_da]

Completed ProductService unit testing using JUnit 5 & Mockito ✅
All service methods tested.
Next: Spring Security (JWT) 🔐
#Java #SpringBoot #JUnit5 #Mockito #SpringSecurity #BackendDev #NitiKart

[Nitish kumar @nitish_da]

Tested CategoryService in NitiKart ✅
All methods covered using JUnit & Mockito.
CRUD & exception handling verified.
Next: ProductService 🚀
#Java #SpringBoot #UnitTesting #Mockito #JUnit"

[Nitish kumar @nitish_da]

Day update 🚀
Completed Product module in my Spring Boot project NitiKart ✅
✔️ Add / Update / Delete
✔️ Search by keyword
✔️ Update product image
✔️ Postman tested APIs
Next: integrations & enhancements 💡
#Java #SpringBoot #BuildInPublic #BackendDev #NitiKart

[Nitish kumar @nitish_da]

@ethanmonkhouse 🙌

[Nitish kumar @nitish_da]

Day X – NitiKart Backend 🚀

✔ Implemented ProductDTO
✔ Created ProductResponse
✔ Built ProductController
➡ Next: Product Service layer & business logic
#BuildInPublic #SpringBoot #Java #BackendDev #NitiKart

[Nitish kumar @nitish_da]

Day 6 – NitiKart Backend 🚀

✔ addProduct()
✔ getAllProduct() in ProductService
Next: Remaining product APIs 🔜

#BuildInPublic #SpringBoot #Java #BackendDev #NitiKart

[Nitish kumar @nitish_da]

Day 4 🚀
Implemented Pagination for Category in my Spring Boot e-commerce backend (NitiKart).
Cleaner APIs, better performance, scalable data handling.
#Day4 #SpringBoot #Java #Backend #BuildInPublic

[Nitish kumar @nitish_da]

Day 3 – NitiKart 🚀

Added:
✅ CategoryDTO
✅ CategoryResponse
✅ Global Exception Handling (@RestControllerAdvice)
APIs are now cleaner & production-ready.
Next → Pagination & sorting
#SpringBoot #Java #BuildInPublic #NitiKart