About
Harshdeep Singh
Backend Engineer — Real-time Systems & AI
I'm a backend engineer working in TypeScript and Node.js, based in Punjab, India. I'm most interested in how systems behave underneath the interface: real-time communication, asynchronous processing, retrieval, and reliability across multiple processes.
The public evidence is two systems. Semantask is suggest-first work coordination on a real-time chat stack — HTTP persists, Socket.IO only transports, a Mongo outbox feeds leased workers. Knowledge Workbench is a research notebook with hybrid retrieval over Postgres full-text and Qdrant, and citations that reopen the source.
Both are open-source projects, not services operated with production user traffic.
01Now
Current focus
- SemantaskSuggest-first work coordination: outbox, leased workers, transport-only Socket.IO.More
- Knowledge WorkbenchHybrid retrieval with citation jump-to-source.More
- TanStack AIMerged pull requests on provider adapters, streaming errors and type safety.More
- Looking forBackend, real-time and AI infrastructure roles — full-time or internship, remote welcome.More
02How I work
Rules I keep coming back to
Each one comes from a decision — or a mistake — in Semantask.
- 01Pick one source of truth and make everything else derive from it
- 02Stateless processes scale; stateful processes page you at 3am
- 03Decoupling is not free — count the hops
- 04Fail closed on the things that matter, fail open on the things that don't
- 05At-least-once is the default; idempotency is the design work
- 06Make failure handling a first-class section, not an afterthought
- 07Bounded everything: timeouts, retries, iterations, history
- 08Write the limitation down the moment you take the shortcut
- 09Optimize for the next engineer reading the code under pressure
- 10Earn complexity; don't assume it
03Toolkit
What I build with
- Backend
- Node.js
- TypeScript
- Bun
- Express
- Next.js API routes
- REST
- Real-time
- Socket.IO
- WebSockets
- Redis pub/sub
- Presence
- Data & retrieval
- MongoDB
- Redis
- PostgreSQL
- Qdrant
- Hybrid retrieval
- AI systems
- LLM provider abstraction
- Leased task workers
- Tool calling
- Structured outputs
- Grounded streaming with citations
- Infrastructure
- Docker
- Docker Compose
- Turborepo
- pnpm
- AWS S3
- Caddy
- Frontend
- Next.js
- React
- TanStack Start
- Tailwind CSS
- Zustand
04Background
Education and availability
Education
Bachelor of Computer Applications
Rayat Bahra University, 2026
Most of the practical learning came from building projects and contributing to open source.
Open to
- Backend engineering
- Platform engineering
- AI infrastructure
- Real-time systems
- Open-source collaboration
- Startup environments
Remote: yes. Relocation: open to discussing for the right role.