on my flight to san francisco i sat next to a 78 year old man.
travelling alone. no wife, no children. flying out for a parkinson's research test.
he told me his wife passed away last year. but before she died, someone else had volunteered for the research program. that person's contribution led to a treatment that gave him five extra years with his wife.
five years he wasn't supposed to have.
now he was doing the same thing. giving himself to the research so someone else might get five more years too.
he said it like it was obvious. like there was no other option.
i've been thinking about that conversation since i landed.
what it looks like to give yourself fully to something knowing you'll never see the result.
I wanted to build a 100% Made in India water flosser.
So I invested ₹40 lakhs and 2 years of my life.
The result?
Not one product that met global quality standards.
Today, that investment is almost zero.
The problem isn't that India can't manufacture.
The problem is the "Chalta hai" mindset.
"Are nahi chalta bhai."
Every "chalta hai" creates another import.
Every compromise tells the world:
"We don't care enough."
Until we obsess over quality,
we will always be slave to foreign imports.
Ok so you've picked a write strategy. Now the other half of the problem.
How do you actually expire stale data?
Two approaches:
1. TTL-based expiry (time-to-live)
Set a timer on every cache entry. When the timer runs out, the data is automatically deleted. Next read triggers a fresh fetch.
Some rules of thumb I use:
- Config data, feature flags → TTL of 5-10 minutes
- Product listings, search results → TTL of 30-60 seconds
- User session data → TTL of 30 minutes
- Versioned static assets → TTL of 1 year (filename changes per version anyway)
Why it works: Dead simple. No extra infrastructure. Set it and forget it.
Where it breaks: You're always accepting some staleness. If the TTL is 60 seconds, a user might see outdated data for up to 60 seconds after a change. For a product listing? Nobody cares. For a bank balance? That's a support ticket.
2. Event-driven invalidation
Instead of waiting for a timer, you actively delete or update the cache the moment the underlying data changes.
How:
- Database writes trigger an event (via CDC, a message queue, or app-level hooks)
- A consumer listens for that event and invalidates the cache immediately
Why it works: Cache is always fresh. No staleness window. Precise.
Where it breaks: You need infrastructure for it. A Kafka consumer or a database change stream (Postgres logical replication, MongoDB change streams, DynamoDB streams). More moving parts. More things to monitor. More things that can fail silently.
Which one should you use?
Honestly? Start with TTL. For most data in most systems, a 30-60 second staleness window is invisible to users.
Add event-driven invalidation only for data where staleness actually costs you something:
- Inventory counts (overselling)
- Pricing (showing wrong price)
- Permissions/auth (security risk)
- Real-time features (chat, live dashboards)
Everything else? TTL. Don't over-engineer it.
Quick decision cheat sheet:
Format: What you're caching → Strategy → Invalidation
1) Product listings → Write-around → TTL (30-60s)
2) User sessions → Write-through → TTL (30 min)
3) Analytics counters → Write-behind → TTL (short)
4) Inventory / pricing → Write-through → Event-driven
5) Feature flags → Write-around → TTL (5 min)
6) User permissions → Write-through → Event-driven
In 2005, when Prime Minister Manmohan Singh visited JNU, a section of students greeted him with black flags and slogans of protest. The university administration issued notices to students and considered disciplinary action.
In his speech, Singh invoked Voltaire:
"I may disagree with what you have to say, but I shall defend, to the death, your right to say it."
When the administration moved against the protesters, Singh reportedly intervened. Years later, then Vice-Chancellor B.B. Bhattacharya recalled the Prime Minister's message to him. "Please be lenient, Sir."
What stands out is not that a Prime Minister defended the right of students to protest against him. What stands out is that we now regard such conduct as exceptional when it should be the minimum standard in a constitutional democracy.
Listen to what Professor Nandita Narain, legendary Maths teacher of DU & former President DUTA is saying about what ails University education today & why she joined the Cockroach Janta Party protest at Jantar Mantar
@augmentcode email support is not available and I cannot login on support portal. Can you please help with ticket - TKT-65222
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Suhel Seth wrote a wonderful article on Indians. My take on it -
A superb article. The problem is not money, infrastructure, or GDP. It is a lack of values.
Indians got rich faster than they got civilized. We built airports, malls, gated communities, and expressways - but forgot to build respect, courtesy, and consideration for others.
A nation’s character is revealed not by its tallest skyscraper, but by whether its people stand in line, refrain from littering, respect public spaces, and treat strangers with dignity.
Development without values is merely wealth wrapped around disorder.
This is not 2011. It takes enormous courage and grit to hit Delhi streets and protest against this govt. More power to Gen Z, to CJP, to this moment. ✊🏽
While coming from my Norway trip ,
At Schiphol Airport I noticed citizens of the US, Canada, EU countries, Japan, South Korea, Singapore and even Malaysia walking straight through automated eGates.
No queues. No officer. No questions.
India was missing from that list.
We stood at least an hour before our turn came to see the officer.
It was a small reminder that GDP headlines and geopolitical chest-thumping are one thing.
Global trust in a country’s documents, institutions and migration profile is another.
A passport is not just a travel document.
It is a report card of how much the world trusts the systems behind it.
This is iconic 👏
Shekhar Suman just narrated the story of a Cruel King.
He didn’t name anyone but this fits perfectly on a man we all know.
Must- Must Watch.
Landed.
Looking forward to meet you all at Jantar Mantar. Do not forget to carry a book and our Tiranga!
Offer flowers to policemen as a gesture of compassion & gratitude.
We have to lead this movement with love and peace!
This is either brilliant or scary:
Anthropic accidentally leaked the TS source code of Claude Code (which is closed source). Repos sharing the source are taken down with DMCA.
BUT this repo rewrote the code using Python, and so it violates no copyright & cannot be taken down!
Forget demographic dividend. We will soon face a demographic nightmare. In the last 10 years:
1. 93000 schools closed down.
2. Enrolment in schools fell 2.41 Crores
3. Population shot up by 15.4 Crores.
In 2015, India had 20.7% people enrolled in schools. In 2025, we have 16.8% enrolled in schools. We saw a 19% drop in school enrolment in proportion to population in a decade.
All this is UDISE data, which is government data.
🇮🇳 Good morning India! A lot of you asked for full-length mock JEE Main tests in @GeminiApp at no cost - done! Good luck on your prep!
Last week, SAT. This week, JEE.
What other global exams would be most helpful?