# Rohosen Bhattacharya

> Roho is a senior full-stack engineer based in India, ex Senior Founding Engineer at Periskope, ex Senior Engineer at Fireflies AI with heavy domain knowledge in payments infra and AI agents. M.Sc. in Human-Computer Interaction from the University of Nottingham.

## Experience

- Senior Full-Stack Engineer @ Payments Team, Fireflies AI (2026): Scaling the payments infrastructure with 20+ million monthly active users.
- Senior Founding Engineer, Periskope (2026): Building the AI Agents and Automations for WhatsApp at Periskope
- Full-Stack Developer, Periskope (2023 - 2025): One of the first 5 employees. Owned large features end to end.
- Full-Stack Developer, SimpliML (2023): Built the foundation of the product from ground up.
- UI/UX Designer, Frenzopay (2022 - 2023): Solo designer. Built the entire product design from scratch.

## Education

- M.Sc. Human-Computer Interaction, University of Nottingham (2023 - 2024), Distinction
- CS50x: Introduction to Computer Science, Harvard University (2023), Certificate
- B.Sc. Neuroscience, Amity University Noida (2020 - 2023)

## Skills

- Frontend: React, Next.js, Shadcn, Tailwind
- Backend: Node.js, NestJS, Express, PostgreSQL, Firebase, MongoDB
- Tools: Stripe, Chargebee, Clickhouse, Claude, Codex, Devin, Unity
- Languages: Typescript, Javascript, Python, SQL, C#
- Design: Figma, After Effects, Illustrator

## Contact

- Email: rohosen2@gmail.com
- https://github.com/roho7
- https://www.linkedin.com/in/rohosen-bhattacharya-9311611aa/
- https://x.com/Rohosen_

## Projects

- [Office Paglu](https://roho.live/project/office-paglu) (Side Projects, 2026): Office Paglu is a print-on-demand merch brand for Indian corporate life,. I built this brand with my girlfriend. Office Paglu runs on a custom Next.js storefront, an Express and Supabase backend that routes orders to print vendors, WhatsApp order tracking and cart recovery, and an AI pipeline for product and ad imagery.
- [Yapn](https://roho.live/project/yapn) (Side Projects, 2026): A local, context-aware dictation app for the Mac that speaks developer. Hold Right Option, talk, let go.
- [Jammune](https://roho.live/project/jammune) (Side Projects, 2026): A browser instrument for jamming with friends. Pick a key, hit a pad, play chords.
- [AI Chat Assistant with Voice Input](https://roho.live/project/periskope-chat-assistant) (AI Engineering, 2026): Built a context-aware AI assistant for Periskope using Gemini and SSE, enabling support agents to automate CRM actions and summarize WhatsApp chats via real-time streaming and voice.
- [Periskope KB + Self Learning](https://roho.live/project/periskope-ai-self-learning-training) (AI Engineering, 2026): I built an automated AI training pipeline for Periskope that extracts knowledge from successful WhatsApp conversations, keeping the AI's knowledge base fresh without manual data labeling.
- [Apex Iconic Website](https://roho.live/project/apex-iconic) (Development, 2026): Developed a landing page for a Real Estate company in Dubai. Complete with custom assets from Higgsfield and a Resend integration to receive registration emails in the company mailboxes.
- [Periskope AI Agent](https://roho.live/project/periskope-ai-agent) (AI Engineering, 2025): An AI Agent that can be trained auto respond to important queries on Whatsapp and raise tickets and communicate with internal team members
- [RAG Pipeline for Periskope AI](https://roho.live/project/periskope-rag-knowledge-base) (AI Engineering, 2025): I engineered a high-precision RAG system for Periskope, grounding WhatsApp AI agents in verified business data using Gemini embeddings, pgvector, and automated document ingestion pipelines.
- [Periskope MCP Server](https://roho.live/project/periskope-mcp-server) (AI Engineering, 2025): I transformed Periskope into an AI-native WhatsApp platform by implementing the Model Context Protocol (MCP), exposing 82 core tools to external LLMs like Claude and Cursor.
- [Serotonin](https://roho.live/project/serotonin) (Development, 2025): For my Master's thesis in Human Computer Interaction at the University of Nottingham, I developed Serotonin, a cross-platform application for tracking and managing mental workload. This app uses synchronizes with your Google Calendar and uses AI to track and accurately measure your mental workload patterns. It also provides feedback and clean visualizations to help users optimize their cognitive resources. This was a single man project that was completed in 3 months.
- [Mathscape](https://roho.live/project/mathscape) (Development, 2024): In the spring semester of 2024, for my Software Engineering Management module, I led the development of "Math Quest Adventure," a 2D educational platformer game targeting 6-14 year-olds. This was a pr
- [Beebo](https://roho.live/project/beebo) (Design, 2021): Beebo is a character that I built based on my favourite TV shows. He is a complete character rig made with Joysticks and Sliders on After Effects.

## Optional

- [Full case studies](https://roho.live/llms-full.txt): every project write-up as plain text