FictionShort Story
The Dawn After Dashami
Dashami night in the Dooars hills. Three friends, a cottage made of glass, and at 4:53 AM, two tigers. One is in the Forest Department's records. The other isn't.
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A house on the internet
Somebody is always home.
A machine in Virginia that has been thinking about prime numbers since July, a library of engineering post-mortems and Bengali short stories, and a workshop of tools you can pick up and use. Wander in.
Bitan SarkarKolkata, India
~/bitan, livelive
$ whoami bitan-sarkar
$ stack Java · Spring WebFlux · AWS
nth prime
connecting…
—
biggest twin prime
(p, p+2)
—
Collatz · no loop ≤
searching for a counterexample
—
longest Collatz
record holder
— steps
your address
resolving…
—
your speed
a few MB, about five seconds
this box never sleeps
Computing right now, and has been for months
The Lab
Where I write things down
Engineering deep-dives and post-mortems from real builds, and short fiction. Different muscles, same notebook.
BengaliShort Story
দশমীর পরের ভোর
দশমীর রাতে ডুয়ার্সের পাহাড়ে একটা কাচের কটেজ, তিন বন্ধু, আর ভোর চারটে তিপ্পান্নয় দুটো বাঘ। একটা বনদপ্তরের খাতায় আছে। আরেকটা নেই।
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JavaSpring
I Thought sync = true Protected My Cluster
Twelve pods, one Redis, and sync = true on the method. I read that as a protected endpoint, but it coordinates one JVM, so a cold key is still twelve calls to the same slow dependency. Why the clustered version is not on Maven Central, what it took to build one, and the case where it makes things worse.
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Devtools
Tools I built because I needed them
Free, no sign-up, no upload. The decoders, formatters and generators run entirely in your browser; nothing you paste leaves the tab.
Paste a production JWT into the decoder; it is parsed in the tab and never reaches the server.
Under the hood
This site is the case study
No WordPress, no Contentful, no database. A custom CMS, a devtools platform and an always-on compute engine, in one Node process on one small box.
- databases
- 0
- Node process
- 1
- JSON files hold it all
- 7
- CMS licence
- $0
Everything you are reading, the copy, the projects, the posts, the timeline, is served from flat JSON and Markdown that I edit through an admin panel I wrote. Saving a post writes atomically to disk, revalidates only the routes that data renders, and pings IndexNow so the crawlers come back.
The interesting part is not that it works. It is which trade-offs it makes, and where they stop being the right ones.
client
Browser
- SSR first paint
- no data fetch on load
- HTTPS
edge
nginx
- TLS
- security headers
- alias /uploads/
- proxy_pass → 127.0.0.1:3002
gate
Middleware
- per-IP + global budget
- jose HS256
- static assets excluded
- NextResponse.next()
app
Next.js standalone · pm2 · one fork
(site)
/admin
/api
engine
sandbox
- server actions
- revalidatePath
- instrumentation hook
- one run at a time
- fs read / atomic write
data
DATA_DIR
content.json
projects · skills · timeline
posts.json + posts/*.md
engagement.json
- tmp + rename()
- survives deploys
- git-diffable