Sarthak Kumar

I build software products, and I keep an honest record of what works.

CSE student at SRMIST, Kattankulathur, class of 2028. I build full systems, from the database rules to the release build: a live 3D globe of Earth-observation data, a private social app with end-to-end encrypted chat, an attendance planner for SRMIST students and a network for finding teammates. I work across full-stack, mobile, security and AI, and I'm a member of PLACVS, SRMIST's placement team.

Polaris globe showing the Americas with 451 natural events and earthquake markers, a layer rail on the left, an event feed on the right and a 7-day timeline below.

Now shipping: PolarisLive Earth-observation data on a 3D globe· last push 25 Oct 2026

Selected work

Four projects, each labelled with where it actually stands: live, in beta, or still being built.

Polaris

LiveWeb app · Geospatial

A world intelligence website: wildfires, storms, earthquakes, aircraft and satellites on a live 3D Earth, each with its source and the time it was observed.

Deployed on Vercel; stored history in PostGIS is the next phase

Next.js 16 · React 19 · TypeScript · CesiumJS · satellite.js (SGP4) · zod · Tailwind CSS · Vitest · Playwright · axe-core

Polaris globe showing the Americas with 451 natural events and earthquake markers, a layer rail on the left, an event feed on the right and a 7-day timeline below.

Vybe

BetaMobile app · Security

A private, Android-first social app: a live friends map with consent-based location sharing, private photo sharing and end-to-end encrypted chat.

APK 0.1.5 published 22 Oct 2026 with push; E2EE chat and push not yet confirmed on a physical phone

Expo SDK 58 · React Native · TypeScript · Kotlin · libsignal · Express 5 · Prisma 7 · PostgreSQL 17 · Firebase Cloud Messaging · Docker · Caddy

System diagram of Vybe, drawn from its architecture notes. Vybe system diagram: Android app with the libsignal module talks over HTTPS and WebSocket to Caddy, which proxies to the Express API and PostgreSQL on one VM.

Bunkr

BetaMobile app

Attendance and timetable for SRMIST students, with planners on top: how many classes you can skip, and what a leave, OD or ML costs.

The Academia sign-in and attendance parser have not yet been checked on a real phone and account

Expo SDK 57 · React Native · TypeScript · Supabase · Row Level Security · zod · Vitest

Repository is private
System diagram of Bunkr, drawn from its architecture notes. Bunkr diagram: the phone signs in to SRM Academia through SRM's own Zoho sign-in, parses attendance on the device, and syncs validated data to a Supabase account protected by row-level security.

Cross Campus

In progressWeb platform

A verified student collaboration network for finding teammates, hackathon partners and research groups, launching at SRMIST.

Built and tested locally; hosting, SMTP and Google OAuth are waiting on credentials

Next.js 16 · React 19 · TypeScript · Supabase · PostgreSQL · Row Level Security · Tailwind CSS · Vitest · Playwright · pgTAP

Read the case studyRepository is private
System diagram of Cross Campus, drawn from its architecture notes. Cross Campus system diagram: Next.js server components call a service layer, which talks to Supabase; Postgres row-level security and security-definer functions enforce authorization.

Bunkr's maths

The question every SRMIST student asks: how many more classes can I miss and stay above 75%? This runs the same functions as Bunkr, copied from its tested shared package.

Everything is integer maths with the threshold as a whole percent, so a value that lands exactly on 75% is never misjudged by floating-point error.

Current attendance 85%

75%

You can skip 5 more classes and stay at or above 75%.

Show the function
/** Largest N such that attended / (conducted + N) stays at or above the threshold. */
export function canSkip(conducted: number, attended: number, threshold: number): number {
  assertThreshold(threshold);
  return Math.max(0, Math.floor((100 * attended - threshold * conducted) / threshold));
}

About

I'm a second-year CSE student at SRM Institute of Science and Technology in Kattankulathur, graduating in 2028. Most of what I know I learned by building things people around me actually need: an attendance planner for my classmates, a place for students to find teammates, a private map for friends.

I like owning the whole system. In one project that meant writing database authorization rules, a Kotlin bridge to libsignal and the server that deploys behind Caddy on a cloud VM. I keep status files in every repo that separate what has been tested from what has only been written, and this site reports my work the same way.

Outside the code I'm a member of PLACVS, SRMIST's placement team, in the corporate domain, and I take part in hackathons whenever I can.

Studying
B.Tech, Computer Science and Engineering, SRM Institute of Science and Technology
Campus
Kattankulathur (KTR)
Graduating
Aug 2024 – 2028 (expected)
Campus involvement
PLACVS SRMIST, Corporate Domain
Learning right now
  • End-to-end encryption with the Signal protocol
  • Postgres row-level security as an authorization layer
  • Native Android builds and signed over-the-air updates
Interested in
Full-stack development, AI / ML and generative AI, Cybersecurity, UI / UX, Software engineering, Cloud and DevOps
Sarthak Kumar on a rooftop, looking out over a lake and hills under a cloudy sky

Skills

Only what I have shipped or studied, each with where I used it. No percentage bars.

Languages

  • TypeScriptPolaris, Vybe, Bunkr, Cross Campus
  • JavaScriptWeb projects and coursework
  • SQLCross Campus, Vybe
  • KotlinVybe's libsignal module
  • PythonML coursework
  • C++, C and JavaCoursework

Frontend

  • ReactEvery project
  • Next.jsPolaris, Cross Campus
  • React Native and ExpoVybe, Bunkr
  • CesiumJSPolaris's 3D globe
  • Tailwind CSSPolaris, Cross Campus

Backend

  • Node.js and ExpressVybe
  • Next.js route handlersPolaris's data collectors
  • SupabaseCross Campus, Bunkr
  • PrismaVybe
  • WebSocketsVybe
  • zod validationPolaris, Bunkr, Cross Campus

Databases

  • PostgreSQLVybe, Cross Campus, Bunkr
  • Row Level SecurityCross Campus, Bunkr
  • SQLite / SQLCipherVybe (on device)

Security

  • Signal protocol (libsignal)Vybe's end-to-end encrypted chat
  • Auth: argon2id, rotating refresh tokensVybe
  • Database-level authorizationCross Campus, Bunkr

Infrastructure and testing

  • Docker ComposeVybe, Bunkr
  • Caddy and Linux VMsVybe on Oracle Cloud
  • VercelPolaris
  • Vitest, Jest, PlaywrightPolaris, Vybe, Bunkr, Cross Campus
  • Git and GitHubEvery project

Activities

  1. Feb 2025 – present

    PLACVS, SRMIST

    Member, Corporate Domain

    Volunteered across 20+ campus placement processes, supporting workshops, seminars and placement activities with a student team.

  2. Jul 2026

    Navjyoti India Foundation, Bawana

    Intern

    One-week community education internship on the 'Classroom Engagement & Success Story of Alumni' project.

  3. Jun 2026

    Project Zenith: The Celestial Eye

    Round 1 submission

    Submitted Zenith Quest, a real-time sky guide.

  4. Apr 2026

    Ossome Hacks, GitHub Community SRMIST

    Participant

    Hackathon participation.

  5. 2026

    HACK NOVA 3.0

    Team Cognitive Coders

    Planned LexiLearn, a dyslexia screening and learning-support platform, with three teammates.

  6. 2025

    Smart India Hackathon

    Shortlisted at university level

    University-level shortlist.

  7. Ongoing

    Computer Society of India, SRM KTR

    Member

    Helped organise tech events and workshops. Also an NSS outreach participant (education).

Contact

Internships, hackathon teams, or a project you want a second pair of hands on: email is the fastest way to reach me.