akhilesh kumar ojha

Software Engineer | React | Node | TypeScript | php |python | Daily quizzes, code reviews & tech explanations | India | RTs ≠ endorsement

[akhilesh kumar ojha @kumarakh]

@Umesh__digital Use a resumable, chunked upload with a server-tracked upload session and idempotent part uploads; on failure, the client queries uploaded parts and resumes from the last acknowledged chunk, then commits with checksum verification.

[akhilesh kumar ojha @kumarakh]

@CyberRacheal A. 13.16.123.1
The other addresses belong to the RFC 1918 private address ranges:
10.0.0.0/8
172.16.0.0/12
192.168.0.0/16
Therefore, 13.16.123.1 is the only public IP in the list.

[akhilesh kumar ojha @kumarakh]

You discover a cron job that runs every minute.

Nobody knows what it does.

Nobody wants to delete it.

It's been running in production for 6 years.

What's your next move?

[akhilesh kumar ojha @kumarakh]

A developer says:

"We don't need rate limiting.

Our users are trusted."

Would you approve this for production?

Why or why not?

[akhilesh kumar ojha @kumarakh]

Your database backup succeeds every day.

One day you try to restore it.

The restore fails.

Did you ever really have a backup?

What's the most important lesson here?

[akhilesh kumar ojha @kumarakh]

@javarevisited The best SQL optimization isn't always changing the query.

Sometimes it's understanding the schema.

If a column is already guaranteed unique by a primary key or unique constraint, adding "DISTINCT" adds noise and may add work. Know your data before optimizing your SQL.

[akhilesh kumar ojha @kumarakh]

Your database backup succeeds every day.

One day you try to restore it.

The restore fails.

Did you ever really have a backup?

What's the most important lesson here?

[akhilesh kumar ojha @kumarakh]

A developer says:

"We don't need rate limiting.

Our users are trusted."

Would you approve this for production?

Why or why not?

[akhilesh kumar ojha @kumarakh]

You discover a cron job that runs every minute.

Nobody knows what it does.

Nobody wants to delete it.

It's been running in production for 6 years.

What's your next move?

[akhilesh kumar ojha @kumarakh]

@sesigl When traffic spikes,adding more concurrency isn't automatically the answer.

If the system is waiting on I/O,cheap concurrency helps. If it's CPU-bound,more workers often just increase contention.

Before choosing a concurrency model, identify what resource is actually saturated.

[akhilesh kumar ojha @kumarakh]

@fromcodetocloud apt and apt-get aren't competitors.

Think of apt as the human-friendly interface and apt-get as the automation-friendly interface.

For update, both refresh package metadata. The difference is mostly about UX, output formatting, and scripting stability.

[akhilesh kumar ojha @kumarakh]

@cyber_razz A PIN is a classic example of a "something you know" authentication factor.

Strong authentication combines different factor types:
• Something you know (PIN/password)
• Something you have (phone/security key)
• Something you are (fingerprint/face)
That's the foundation of MFA

[akhilesh kumar ojha @kumarakh]

@cyber_razz The correct answer is C) 169.254.10.20.

Only 169.254.x.x is the APIPA range, assigned automatically when a device cannot get an IP from DHCP server.

[akhilesh kumar ojha @kumarakh]

@HSC_Consult The correct answer is A) Allowed targets.

Allowed targets where you can legally and ethically conduct security testing for bug bounty rewards.

[akhilesh kumar ojha @kumarakh]

@EOEboh Node.js performance issues are often caused by CPU work, not I/O.

A massive JSON.parse() can freeze the Event Loop because it runs on the main thread. While parsing, timers, callbacks, and incoming requests all wait. Non-blocking I/O doesn't help if JavaScript itself is busy.

[akhilesh kumar ojha @kumarakh]

@SumitM_X HTTP status codes are not decoration.

They are part of the API contract.

Returning 200 OK for every response makes monitoring lie,breaks retry logic,confuses caches,& hides failures from infrastructure.Let HTTP communicate transport outcomes & use the response body for details.

[akhilesh kumar ojha @kumarakh]

Production Scenario:

2:13 AM.

API error rate: 35%
Database CPU: 95%
50,000+ active users online.
The CEO just texted:
"Customers can't place orders."
You can only do ONE thing first:

A. Restart DB
B. Rollback
C. Read-only mode
D. Investigate
What's your call?

[akhilesh kumar ojha @kumarakh]

Production Scenario:

2:13 AM.

API error rate: 35%
Database CPU: 95%
50,000+ active users online.
The CEO just texted:
"Customers can't place orders."
You can only do ONE thing first:

A. Restart DB
B. Rollback
C. Read-only mode
D. Investigate
What's your call?

[Python Programming @PythonPr]

Machine Learning Algorithms

[akhilesh kumar ojha @kumarakh]

A bug hits production.

Users can't log in.

You have 30 minutes.

What's your first priority?

A. Find Root Cause
B. Roll Back
C. Communicate Status
D. Check User Impact

[akhilesh kumar ojha @kumarakh]

@TrisH0x2A Turbo c is my first editor for printf("Hello world");