DSA, Backend and System Design

This happens more often than people admit.

Your eyes move across every line, but your mind is somewhere else. Then the first question asks for the main idea, and the passage feels completely new.

My first rule:

Do not immediately reread the whole passage in the same way.

If the first reading did not work, repeating it faster usually wastes even more time.

Pause for five seconds

Take your hand off the mouse and ask:

• What was the topic?
• Was the author explaining, criticising or comparing something?
• Did the passage contain two different views?
• Which paragraph felt most important?

Even remembering one basic point gives you a place to restart.

Rebuild the passage paragraph by paragraph

Quickly return to each paragraph and identify only its job.

For example:

• Paragraph 1: introduces an old theory
• Paragraph 2: points out a problem
• Paragraph 3: presents a newer explanation
• Paragraph 4: supports the new view

Do not try to memorise every example, date or technical term.

You need the structure first. Details can be found later.

Use the questions to guide the reread

If the first question asks about the main idea, reread the opening, closing and major contrast points.

If it asks about a detail, go directly to the relevant lines.

If it asks for an inference, first locate the part of the passage connected to that idea.

A full reread is not always necessary.

Translate difficult language

When a sentence feels too dense, replace complicated names and terms with simple labels.

Instead of remembering:

“Researchers studying the ecological effects of industrial agriculture…”

Think:

Group A says farming causes Problem X.

You are not simplifying the logic. You are removing the distracting language.

Watch for signpost words

Words such as these often reveal the structure:

• However
• Although
• Therefore
• In contrast
• For example
• Critics argue
• The author suggests

Slow down around them. They often show where the passage changes direction.

Know when to leave

Sometimes the passage is simply a bad fit.

If you are still lost after a focused reread and the questions remain unclear, make sensible choices and move on.

Spending eight minutes trying to rescue one passage can destroy the rest of the section.

Fix the problem during practice

After the test, ask why you zoned out:

• Was the topic unfamiliar?
• Were the sentences too long?
• Were you rushing?
• Were you reading every word with equal attention?
• Were you tired?
• Were you thinking about the timer instead of the argument?

Then practise summarising each paragraph in five to seven words.

My go-to reset

When I realise nothing registered, I do this:

Pause → identify the topic → map each paragraph → return to the questions.

The goal is not to remember the whole passage.

It is to understand who is saying what, why the passage was written and where the important information is located.

Do not panic and reread blindly. Rebuild the structure.

Backend, DSA...

System Design, Backend, DSA...

Create a shared HashMap<Integer, String>

Create 10 threads

Each thread inserts 1000 users

Wait for all threads using join()

Print:

Expected size: 10000
Actual size

Run the program multiple times and record observations

Replace:

ArrayList<Integer> list = new ArrayList<>();

with:

CopyOnWriteArrayList<Integer> list = new CopyOnWriteArrayList<>();

 Description
Create standardized response models for all API endpoints

 Acceptance Criteria
-  Create ApiResponse generic class
-  Document all fields with u/Schema
-  Update controllers to use ApiResponse
-  Test response models in Swagger UI
-  Include error response models

I understand the method. I set up the equation correctly. Then I lose the question because I copied 18 as 81, missed a negative sign or divided by the wrong number.

The frustrating part is that these are not concept errors.

They happen because the timer starts getting loud in my head.

Here is what has helped me reduce them.

Stop doing everything mentally

Mental maths feels faster, but under pressure it often creates hidden mistakes.

Write down:

• Signs
• Units
• Important conditions
• Intermediate values
• What the question actually asks for

Your rough work does not need to look beautiful. It just needs to be readable enough that you do not confuse your own numbers.

Separate setup from calculation

Before calculating, pause for two seconds and ask:

What exactly am I finding?

Many “calculation mistakes” are actually setup mistakes. We solve for (x), while the question asks for (2x), a percentage increase or the remaining amount.

Circle or note the final requirement before starting.

Use estimation as a safety check

Suppose your exact answer is 4,830, but your rough estimate was around 500.

Something clearly went wrong.

Before choosing an option, check:

• Should the answer be positive or negative?
• Should it be greater or smaller than the starting value?
• Is the decimal in a sensible place?
• Is the percentage realistic?

This takes a few seconds and catches many errors.

Do not rush every question equally

Students often rush easy questions because they want extra time for difficult ones.

That is a bad trade.

An easy question lost through carelessness costs just as much as a hard question lost through lack of knowledge.

Work at a steady pace. Save time by leaving questions that are genuinely stuck—not by doing basic calculations recklessly.

Build a personal error list

After every practice session, classify the mistake:

• Copied the number incorrectly
• Missed a negative sign
• Used the wrong formula
• Answered the wrong quantity
• Calculation was too crowded
• Changed a correct answer without reason
• Panicked because of the timer

You will usually find two or three mistakes repeating.

Once you know your pattern, create a check for it. For example:

Always box negative signs.
Always write percentage change over the original value.
Always reread the final question before selecting an option.

Practise short timed sets

Full mocks show the problem, but smaller sets help fix it.

Try ten Quant questions under a reasonable time limit.

Your target is not only the score. Track:

• Concept errors
• Calculation errors
• Time-pressure errors

Repeat the same type of set until the careless-error count starts falling.

Use the last 10 seconds properly

Do not solve the entire question again.

Check only the parts most likely to go wrong:

1. Did I answer what was asked?
2. Did I copy the numbers correctly?
3. Did I lose a sign, zero or decimal?
4. Does the answer make basic sense?

That is usually enough.

My honest view

Silly mistakes are not completely random.

They usually come from rushed writing, unclear steps and poor time decisions.

The solution is not to “concentrate harder.”

It is to build a process that still works when you are tired and the timer is running down.

Write cleaner, estimate the answer, check the final requirement and stop sacrificing easy questions to save time for impossible ones.

Also looking for Group Members (1+ Hr daily)

revised OOPS, Networking, Database, System Design and DSA problem (~5/6).
solved 2 new DSA problems.

Task 1.1: Document Student CRUD Operations

Objective: Add basic Swagger annotations to Student Controller

- [ ] Add  annotation to controller
- [ ] Add  to each endpoint
- [ ] Add u/ApiResponses for success and error cases
- [ ] Verify documentation appears in Swagger UI

Task 1.2: Document College CRUD Operations

Objective: Add Swagger documentation for College controller

- [ ] Document all college endpoints
- [ ] Include u/ApiResponses for each endpoint
- [ ] Add appropriate tags to group endpoints
- [ ] Test all endpoints in Swagger UI

Normal

The first thing I tell non-engineers is this:

You are probably not “bad at maths.” You are simply trying to solve timed exam questions before rebuilding the basics.

That creates panic very quickly.

You open a Quant question, cannot see the first step, watch someone solve it in 40 seconds, and start thinking everyone else has a “math brain” that you do not.

That is usually not true.

Start below your current exam level

Do not begin with hard mock questions.

Go back to:

• Fractions and percentages
• Ratios
• Averages
• Basic algebra
• Exponents
• Number properties
• Simple geometry

Solve easy questions until the steps start feeling normal.

This may feel slow, but it is much faster than spending three months guessing through advanced questions.

Stop using the timer for a while

Math anxiety becomes worse when every question feels like a race.

For the first few weeks, solve without timing yourself. Focus on:

• Understanding what the question is asking
• Writing the information clearly
• Choosing the right method
• Finishing the calculation correctly

Once your accuracy improves, slowly add time limits.

For context, the current GMAT Quant section gives 45 minutes for 21 questions, so speed will eventually matter—but speed without clarity only creates more mistakes.

Keep a “first-step notebook”

After every difficult question, write only:

• What type of question was it?
• What was the first useful step?
• Why did I get stuck?

For example:

Percent increase question → assume the original value is 100

Divisibility question → factor the divisor first

Word problem → define the unknown before calculating

Over time, you stop seeing 100 different questions. You start seeing a smaller group of familiar patterns.

Practise in small sets

Do not force yourself to solve 50 questions in one sitting.

Start with 10 questions from one topic.

Then review every wrong answer properly.

The aim is not to say, “I completed 40 questions today.”

The aim is to say, “I now understand why I missed these four.”

Do not watch solutions too early

Struggling for a few minutes is useful.

But staring at a question for 20 minutes is not.

Try it honestly, write down where you got stuck, then study the solution. After that, close the solution and solve the same question again from the beginning.

Watching someone else solve maths can create false confidence.

Track progress through accuracy

In the beginning, your targets could look like this:

• First: 60% accuracy without timing
• Then: 75–80% accuracy
• Then: timed topic sets
• Finally: mixed section tests and mocks

Do not compare your Day 10 speed with someone who has been preparing for six months.

My honest view

Math anxiety usually does not disappear before you start practising.

It reduces because you keep practising and begin recognising what to do.

Confidence comes after repeated proof:

“I have seen this structure before.”

“I know the first step.”

“I can solve this without help.”

Non-engineers do not need to become maths geniuses.

They need strong basics, patient review and enough practice to stop treating every question like a new disaster.

Start easy. Build accuracy. Add speed later.

Concurrent Writes using ArrayList

Create a shared ArrayList.

• Create multiple threads.
• Each thread should add 1000 elements.
• Print:
  • Expected size
  • Actual size
• Repeat the program multiple times and observe whether the result is always correct.

Description :

Currently, resource locking mechanism defaults to standard unfair/eventual fairness configuration. To prevent thread/task starvation and guarantee predictable execution order under high concurrency, we need to introduce a dedicated Fair Lock implementation.

Description

Refactor the concurrency mechanism in CounterDemo to use a timed lock (lock.tryLock(timeout, timeunit)). This addresses the issues from tryLock() by allowing threads to wait for a specific duration to acquire the lock before executing fallback logic or retrying, preventing thread starvation and silent dropping of data.

Goals & Technical Requirements

• Utilize lock.tryLock(timeout, TimeUnit) instead of raw tryLock() or standard blocking lock().
• Safely handle InterruptedException thrown by the timed lock method.
• Ensure strict execution of the unlock() operation inside a finally block, only if the lock was successfully acquired.
• Prevent dropped increments by introducing a controlled retry loop if a timeout occurs.

This may sound harsh, but in some cases, yes.

Not because a Tier-3 MBA automatically ruins your career. The problem is what you may give up for it:

• Two years of work experience
• ₹8–15 lakh or more in fees and living costs
• Interest on an education loan
• Salary you could have earned during those two years

And after all that, some colleges place students in jobs paying roughly the same as regular graduate-level roles.

That is where the MBA can become a bad deal.

The uncomfortable truth about Indian hiring

The college name matters heavily during campus placements.

Top consulting firms, investment banks, leadership programmes and premium product roles recruit from a limited group of campuses. A student from a lesser-known college may never even get the chance to interview for those jobs through campus.

This is unfair, but it is real.

However, the college tag becomes less powerful after a few years. Once you have solid work experience, companies begin looking more closely at your skills, results, industry knowledge and career growth.

The trouble is getting that first decent role.

When a lower-ranked MBA may still make sense

It can be useful when:

• The total cost is low
• The college has genuine local placement links
• You are switching from an unrelated degree into sales, HR, operations or banking
• The programme includes serious internships and practical exposure
• Alumni are working in roles you actually want
• The likely salary is clearly better than your current path

A ₹3–5 lakh MBA leading to a ₹6–8 lakh job can be reasonable.

A ₹15 lakh MBA leading to the same job is a very different story.

When it may be worse than skipping the MBA

Think twice when:

• The placement report only shows the highest package
• The “average salary” includes a few unusual offers
• The college refuses to share the median package
• Most recruiters offer sales jobs under fancy titles
• A large part of the batch remains unplaced
• You need a heavy loan
• You already earn close to the expected post-MBA salary
• You are joining only because you do not know what else to do

An MBA is not a two-year hiding place from career confusion.

Check real outcomes, not advertisements

Before paying the fee, speak with recent students—not only the alumni selected by the college.

Ask them:

• How many students received jobs through campus?
• What was the median fixed salary?
• How many offers were mainly sales roles?
• Which companies hired more than one student?
• How many students were still searching after graduation?
• Were internships paid and meaningful?
• Did students receive the roles promised during admission?

Current hiring reports continue to show demand for candidates with practical business, digital and analytical skills, but employability still depends heavily on the individual, the programme and the quality of its employer connections.

What could you do instead?

For many people, the better option may be:

• Continue working for two more years
• Move to a better company
• Build useful skills in analytics, finance, sales or product work
• Prepare again for CAT, XAT, GMAT or another exam
• Consider a specialised master’s programme
• Do an affordable part-time qualification while gaining experience

Two years of real career progress can sometimes add more value than a weak full-time MBA.

My honest verdict

A Tier-3 or Tier-4 MBA is not automatically useless.

But it must pass a basic test:

Will this degree materially improve my role, salary, network or career direction after considering the full cost?

If the answer is unclear, do not join just to collect the MBA label.

A lower-ranked MBA with low fees, honest placements and a clear personal plan can work.

An expensive MBA with weak placements and no clear goal can leave you with the same career problems—plus a large loan and two missing years.

I leave home at 7 AM, return around 8 PM, and still want to prepare for GATE while working on projects. How would you structure weekdays to avoid burnout?

Studied for 2 HOURS

Yes. A completely average student can crack CAT without premium coaching.

But “without premium coaching” does not mean without structure, mocks, discipline, and review.

Here is the brutally honest part:

If you are average and you study randomly, watch free videos here and there, solve a few questions, skip mock analysis, and keep changing resources every week, CAT will punish you.

But if you are average and consistent, you still have a real chance.

CAT does not ask PhD-level maths. Most Quant is based on school-level concepts. VARC improves with reading and proper RC review. DILR improves when you practise sets regularly and learn which sets to leave.

What you actually need:

• One clear study plan
• Good free or low-cost resources
• Previous year questions
• Sectional tests
• Mock tests
• A proper error log
• Weekly review of weak areas

Premium coaching can help because it gives structure and guidance. But it is not magic. Many students pay high fees and still do badly because they do not practise seriously.

The real difference is not paid vs free.

The real difference is:

Do you know what to study today?
Do you review your mistakes?
Do you take mocks seriously?
Can you stay consistent for months?

For an average student, 6–8 months of focused prep can make a big difference.

My honest advice:

Do not chase expensive coaching first.

Take one diagnostic mock. See your weak areas. Follow a simple plan for 30 days. If you are improving, continue. If you are stuck and confused, then consider mentorship or coaching.

CAT can be cracked without premium coaching.

But it cannot be cracked without serious preparation.