Nidhi Tiwari

Java developer writing about system design, scalability, AKS, AI, real-world code mistakes.

[Nidhi Tiwari @NidhiDevNotes]

Hello,
I share real scenarios I deal with as a backend engineer.

Mostly around:
• Java
• System Design
• AKS / Cloud
• Production edge cases

Lately I post question-based scenarios, the kind interviewers ask and the kind that actually break in production.

If you enjoy solving these, consider following. New questions every day.

[Nidhi Tiwari @NidhiDevNotes]

@javarevisited Because id is usually an integer not a string. So comparing it with abc makes no sense and can cause type conversion issues or errors depending on the database.

[Nidhi Tiwari @NidhiDevNotes]

AI is changing things so fast that sometimes it genuinely feels unreal.

There was a time when making notes was an actual task. Watching a 2-hour YouTube tutorial meant sitting with a notebook for 4 hours.

Pause the video. Write everything down. Rewind because you missed a point. Take screenshots. Highlight important timestamps.

Now I just paste the YouTube link into NotebookLM and within a minute it gives me proper notes, summaries, key points, FAQs, even a podcast-style discussion from the same content.

What’s crazy is not just the tool itself.
It’s how normal all this is starting to feel.Things that genuinely took hours of effort now happen in minutes.

Feels like AI is quietly changing the way humans learn, work, study, research… everything.

#AI #notebookllm #notes

[Nidhi Tiwari @NidhiDevNotes]

@SumitM_X All 10 APIs are tied to one big DTO, so if you change even one field, you risk breaking everything. It’s tightly coupled and hard to maintain.

[Nidhi Tiwari @NidhiDevNotes]

it’s not immediately garbage collected.

When you do emp = null, you’re just removing your reference to the object. It’s like you’ve stopped pointing to it but the object is still sitting in memory.

The garbage collector will clean it up later whenever it runs and sees that nothing is using that object anymore. You don’t control exactly when that happens.

[Nidhi Tiwari @NidhiDevNotes]

@SumitM_X First I’d not assume it’s harmless. I’d check memory usage and GC logs to confirm there’s actually a leak then diff recent changes and profile the app to see what’s retaining objects.

[Nidhi Tiwari @NidhiDevNotes]

@GamewithDave Super Mario

[Nidhi Tiwari @NidhiDevNotes]

@javarevisited it has no WHERE clause, so it updates all rows in the table not just a specific user. In this case, every user would be granted admin privileges at once, which is a serious security breach and can completely break the system’s access control.

[Nidhi Tiwari @NidhiDevNotes]

10 rows from the Customers table, starting after the first 10 rows. So you get rows 11 to 20 based on whatever ordering the database uses.

If there is no ORDER BY clause, the rows returned are not guaranteed to be consistent. the “first 10” depends on how the database physically stores or retrieves data.

PS: I post similar content. Please check out my page and follow if it interests you.

[Nidhi Tiwari @NidhiDevNotes]

@ASpittel Old idea, new buzzwords. still runs at 3am.

[Nidhi Tiwari @NidhiDevNotes]

@ThePrimeagen Expectations loading faster than the model

[Nidhi Tiwari @NidhiDevNotes]

@dpratyush02 Owning the platform = owning attention + access.
You don’t charge users. You charge anyone who wants to reach them.

[Nidhi Tiwari @NidhiDevNotes]

@vandanasoc28779 I post bout java, system design and AKS. Please check out my Page and follow if it interests you.

[Nidhi Tiwari @NidhiDevNotes]

@bluewmist I remove choice. Fixed time, fixed routine.
No decision, no excuses.

Parkinson’s Law: work expands to fill the time you give it.

[Nidhi Tiwari @NidhiDevNotes]

@AishwaryaDevv Wait till they hear about REST, they’ll start looking for a couch

[Nidhi Tiwari @NidhiDevNotes]

@EOEboh Orchestrator sounds cool but someone still needs to know why things work.

[Nidhi Tiwari @NidhiDevNotes]

@vivoplt Cool. Now try modifying it without AI.

[Nidhi Tiwari @NidhiDevNotes]

@bidhaan_daju VS code

[Nidhi Tiwari @NidhiDevNotes]

@javarevisited ecause Kafka is built for streams, not state.

Kafka-> append-only log (event history)
Database -> current state (query, update, index)
Kafka can store data, but,
No efficient querying
No relational constraints
No flexible updates

[Nidhi Tiwari @NidhiDevNotes]

Raw types in Java skip type safety-> Bugs show up at runtime.
#Java #Programming #Coding #JavaTips #BestPractices #Developers #SoftwareEngineering

[Nidhi Tiwari @NidhiDevNotes]

@Zoomie175 Hey, so glad it helped you.

[Nidhi Tiwari @NidhiDevNotes]

Arrays in Java: the most basic DS, but still powerful

public int sum(int[] nums) {
int total = 0;

for (int num : nums) {
total += num;
}
return total;
}

Why beginners should care:
Arrays teach you the core habit. Traverse data, process each element

Everything builds on this:
• Prefix sums
• Sliding window
• Dynamic programming

Real insight:
If you can’t solve problems with arrays, you won’t solve them with complex DS either.

Start simple. Go deep.
#Java #DataStructures #DSA #Beginners #Coding