@biswaviraj · India

Biswajeet Das

Lead Software Engineer

Currently building a realtime AI platform at Lightwork AI.

I'm happiest in the parts most people skip. Data layers, auth, cache invalidation. The wiring that decides whether a system actually works.

Let's work together

Experience

6 + years

Backend, SDKs & full-stack

Shipped at Novu

85 % smaller

@novu/js bundle · 157KB → 21KB

Profile

Orientation

Right now I'm Lead Product Engineer at Lightwork AI, building a realtime AI property-management platform on NestJS microservices and WebSockets behind a Next.js surface, scoping with the CEO and shipping from API to UI.

The throughline across six years is the backend and the wiring: data layers, distributed systems, auth, realtime. One chapter of that is Novu, the open-source notification infrastructure, where I architected parts of the core workflow engine and built the SDKs that ship it. The full record is logged below.

I also build and ship my own: Hexbench, EngineView, hour.zone, miny, plus open-source libraries. More in the work below.

Always looking for hard problems to solve and interesting people to build with.

Focus

Backend services
Distributed systems
SDK & DX
Developer tools
Realtime
Web performance
UI/UX

Range

React
Vue
SvelteKit
SolidJS
TypeScript
Node.js
Python
Go

Experience

June 2025 - Present
Lightwork AI (Remote)

Product Engineer (Lead)
- Architected and am leading a zero-trust security model across all microservices: each request carries a signed JWT, verified via JWKS, that downstream services authorize independently. A cross-team initiative spanning the data, AI, and DevOps teams, owned end to end from ADR and technical spec to design presentations.
- Built the realtime WebSocket layer end to end, backend and frontend: the NestJS gateway and the client that consumes it.
- Built backend services across the NestJS microservices stack: TCP transport between services, Google Pub/Sub events, Postgres and MongoDB, and Better Auth.
- Integrated voice AI agents to handle live calls, building the API and call-handling layer around the LLM.
- Co-led the migration from a legacy React Router app to a modern Next.js stack with Tailwind and shadcn.
- Scoped features with the CEO and Product, shipping from API to UI; set up feature flags and PostHog analytics.
- NestJS
- Node.js
- TypeScript
- Microservices
- WebSockets
- Google Pub/Sub
- PostgreSQL
- MongoDB
- Better Auth
- Zero-Trust Security
- Voice AI
- Kubernetes
- Next.js
- React
- Tailwind CSS
September 2022 - June 2025
Novu (Remote)

Software Engineer
- Architected parts of Novu's core workflow orchestration engine. The system walks a trigger through a multi-step pipeline across email, inbox, SMS, and chat, with subscriber-preference evaluation at every layer.
- Shipped the new Workflows API (NestJS, CQRS-style use-cases) replacing the legacy notification-templates system.
- Built the step-condition system end-to-end on react-querybuilder + JSON schemas (UI + backend), enabling arbitrary per-step rules across workflows.
- Designed the global subscriber preferences engine end-to-end (DAL → use-case → worker → headless and node SDKs).
- Hardened auth (rate limiting, account lockout, password policy), added cursor pagination and fixed cache invalidation in the DAL, and built the Twilio-backed Novu SMS provider with Gupshup DLT compliance.
- Created @novu/react and @novu/next from scratch. @novu/react overtook the legacy @novu/notification-center in npm weekly downloads within months of launch.
- Led architecture and build pipeline on @novu/js, cutting bundle size 85% (157KB → 21KB) and load time 86% vs the legacy @novu/notification-center. Also architected @novu/client and rewrote it off axios onto native fetch.
- TypeScript
- SolidJS
- React
- NestJS
- Node.js
- MongoDB
- WebSockets
- Tailwind CSS
March 2021 - August 2022
Capital Numbers (Remote)

Software Developer

Owned most of the frontend for Blink Payment, a fintech payment-gateway platform. Built the payment flows (virtual terminals, repeat payments) and integrated card processors Cardstream and SagePay. Deployed via AWS CodePipeline, CodeBuild, and CloudFront.
- React
- TypeScript
- Material UI
- Node.js
- AWS
January 2020 - January 2021
NetTantra Technologies (now Hyscaler)

Software Developer

Sole frontend engineer on ZipDJ, a Spotify-style streaming platform built for DJs. Owned the frontend end to end, including the custom music player at the heart of the product, and integrated ElasticSearch for fast search with eager-loading performance work. Also integrated Mega.nz cloud storage for Spinvault.
- React
- SCSS
- ElasticSearch
- Bootstrap
- Node.js