Hey.
I'm Paritosh — a senior full-stack engineer

who owns outcomes, not just code. Five years in, most recently Head of Engineering at Fhynix.

↳ 1,000+ days on LeetCode. not one missed.
scroll to meet me ↓
Paritosh Batish
a bit about me

Nice to meet you

I'm a full-stack engineer based in Chandigarh, India, with 5+ years building products end to end. Most of my recent work is React Native — but the backend is just as real. I care about the systems under the UI, and the cost of running them. Lately that includes AI: RAG pipelines and tool-calling agents in Python.

I tend to own the whole thing. I shipped an Android platform in ~3 weeks against a 3-month vendor quote, took an LLM assistant to production for about $10/month, and designed the recurrence engine the entire product is built on. My arc has been SDE Intern → SDE 1 → SDE 2 → Lead → Head of Engineering — steadily more ownership.

I hold every claim to one standard: would it survive an engineer asking me about it in an interview?

5+
YEARS
EXPERIENCE
3
COMPANIES
INTERN → HEAD OF ENG
Education
B.E., Chitkara University
Patiala, Punjab · 2018–2022 · 9.21 GPA
the quiet part

I show up.

Three-plus years on LeetCode without missing a single day — through jobs, side projects, and everything in between. The same habit shows up in the work I ship.

the road so far

Where I've worked

DEC 2023 — AUG 2026 · MUMBAI, INDIA
Fhynix
Calendar productivity app · React Native · hundreds of active users

Head of Engineering

MAR 2025 — AUG 2026
  • ✶Built an LLM-powered AI assistant from a 2-day MVP to the flagship feature, turning voice, image and text into structured tasks — entirely on the frontend, no AI server — for about $10/month in model costs across hundreds of active users.
  • ✶Designed an RRULE-based recurrence engine, replacing per-instance storage of hundreds of rows per recurring task, with a live, backward-compatible migration — the core system every other feature is built on.
  • ✶Architected a unified task data layer (windowed store + cache + API, one read/write path) that cut production issues from weekly to monthly.
  • ✶Shut down a spam attack that was spiking AWS costs and crashing the service, with rate limiting, request filtering and WAF rules.
  • ✶Built reminder workflow automation: WhatsApp reminders and daily summaries on a Bull queue, plus silent-push notification syncing.
  • ✶Built a self-managed subscription system on App Store / Play IAP using webhooks and reconciliation polling, with no billing SDK; led a small team with a planning-first culture and strict PR reviews.

Lead Engineer (Contract)

DEC 2023 — MAR 2025
  • ✶Shipped the app's entire Android platform — the app was iOS-only — in ~3 weeks of core work, against a vendor's 3-month quote, from core bug fixes through Play Store launch.
  • ✶Cleared a major feature and bug backlog, bringing an inherited codebase to its first production-ready state.
MAY 2021 — NOV 2023 · HYDERABAD, INDIA
CAW Studios

SDE Intern → SDE 1 → SDE 2

Product engineering studio
  • ✶Co-developed a meta-driven no-code UI engine (form + list, React + TypeScript), cutting UI development time by 30%.
  • ✶Built a shared component & service library for web and mobile in an NX monorepo (dependency injection, atomic design) — including an auto-generated API SDK and a unified Redux store.
  • ✶Built ~80% of the frontend for the product that later became the Fhynix app — which I went on to lead.
AUG 2020 — MAR 2021 · CHANDIGARH, INDIA
Anukai Solutions

SDE 1

Civic-tech startup tackling road-traffic safety
  • ✶Built real-time systems with Sockets for the Patiala Foundation — a scalable Node.js REST API with live inventory for a helmet-rental service.
  • ✶Built multi-blackspot accident-area identification with real-time insights using Google Maps, in collaboration with Punjab Police.
  • ✶Digitised end-to-end case filing: role-based workflows (RBAC), approval mechanisms, and automated PDF generation.
the toolbox

What I work with

AI & LLMs
← the new depth
OpenAI API Gemini Amazon Bedrock RAG LangChain ChromaDB Hugging Face embeddings Tool calling Multi-agent orchestration MCP Prompt engineering
Languages & Frontend
JavaScript TypeScript React Next.js React Native Redux Storybook
Backend & Systems
← the real depth
Node.js Express Python FastAPI REST Sockets Webhooks BullMQ MongoDB SQL JWT RBAC rrule
Architecture & Practice
NX Monorepo Dependency Injection MVC Atomic Design Caching layers Cost-aware design
UI Libraries & Tooling
Material UI Chakra UI Styled-components react-native-paper Sentry CleverTap AWS Docker · compose
things I've built

Selected work

FLAGSHIP2023 — 2026

Fhynix — AI Calendar App

A React Native calendar productivity app on iOS + Android, serving hundreds of active users. As Head of Engineering I owned the whole stack — and built its three hardest pieces: an LLM assistant (no AI server, ~$10/month), an rrule recurrence engine with live migration, and a self-built IAP subscription system.

React Native Node · MongoDB Gemini Flash BullMQ · IAP
Fhynix — AI calendar app marketing image
Agentic AI — built in Python
RAG

Chat with PDF

Upload a PDF and ask it questions. Retrieved chunks are reranked with a cross-encoder, and answers from GPT-4o-mini cite page numbers. Gradio UI.

LangChain · ChromaDB HF embeddings Gradio
AI AGENT

InterviewIQ

A tool-calling mock-interview coach with a hand-written agent loop (no framework), retries, a session scorecard that finds your weakest area, and a two-agent mode.

OpenAI API · Groq Tool calling Gradio
AWS · BEDROCK

Travel Assistant

A multi-step planning agent that chains weather, packing and cost tools on its own, then checks the plan against your budget.

Amazon Bedrock Strands Agents SDK
Earlier — things I built exploring
Chandigarh Police social complaints monitor
2019 · CIVIC-TECH

Chandigarh Police — Social Complaints Monitor

A real-time portal that watches Twitter for complaints tagged to Chandigarh Police (#chandigarhpolice, #crime, #pcr) and surfaces them for action. Built in a 36-hour hackathon — recognized by Chandigarh Police.

Python · Flask MongoDB
Public bus location tracking
PROOF OF CONCEPT

Public Bus Location Tracking

Real-time location tracking for public buses to cut waiting times — buses POST their location and the server broadcasts to riders live. My most-developed personal repo.

Express · Socket.IO MongoDB
Google Maps reviews scraper
UTILITY

Google Maps Reviews Scraper

A small Python scraper that pulls reviews from a Google Maps link and saves them to an XLSX file for analysis. Built for educational purposes.

Python XLSX
a few highlights

Wins & recognition

★
Winner — National-Level Hackathon (OWASP)
Thapar University
★
2nd Place — CODATHON 2020
Competitive coding placement
✓
Certificate of Appreciation — Patiala Foundation
For the Helmet Bank project · 2020
✓
Recognized — Chandigarh Police Hackathon 2019
Appreciated for the social-complaints idea (team of 3)
get in touch

Say hi.

Always up for a good engineering conversation — whether it's about systems, cost, or something you're building. Drop me a line.

Paritosh Batish Hand-drawn & built by Paritosh · Chandigarh · 2026