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Backend Engineer · Rust · Kafka · PostgreSQL

Sidharth Singh builds backends that stay correct under load.

Event-driven services, Kafka pipelines and Rust on the hot paths, for platforms that move physical goods. Backend engineer at 1buy.ai in Delhi, learning PostgreSQL internals and Kafka from first principles, in public.

View workResumeGitHub

Open to conversations about distributed backends and hard infrastructure problems.

years in productionRust, TypeScript, Python
2+
documents indexedMongoDB pipelines for real-time discovery
100M+
LLM mail agentsanchor, classify, act
16
place, hackathon 2025across all engineering teams
1st

Now

Right now

A live snapshot of what I am building, learning and writing, pulled from the same files that power the rest of the site.

Now page
NowUpdated 28 Oct 2026
Building
Inbound mail agents: anchor, classify, act
Learning
PostgreSQL internals course · Kafka mastery in Rust
Based in
Delhi, India
Building1buy.ai

Inbound mail agents: anchor, classify, act

An LLM-assisted pipeline that reads every email the fulfilment platform receives, works out which order or shipment it belongs to without trusting the model to decide, routes it to one of 16 plug-in handlers, and dispatches the resulting action through a transactional outbox.

In progressPythonFastAPIPostgreSQLMicrosoft Graph
LearningUpdated 27 Oct 2026

PostgreSQL internals course

Eight-week, internals-first course with weekly assignments, lab experiments on a local Postgres 18 container, and notes written in my own words.

Progress10%

Next: Phase 0 · Lab setup and system catalogs

Writing27 Oct 2026

Building this site in public

The site you are reading is a pilot built in an afternoon. This post is the changelog, the decisions, and what is still rough.

1 min read · #meta #nextjs

Selected work

Featured work

Systems I owned end to end. Each one has the constraints, the approach and what actually shipped.

View all
1buy.ai
Shipped

Concurrent job scheduler in Rust

Rewrote a background job scheduler on Tokio with semaphore-bounded worker pools, so several instances can process jobs concurrently without thread contention or double execution.

  • Rust
  • Tokio
  • MongoDB
1buy.ai
Shipped

One pricing formula, two runtimes: Rust to WebAssembly

Wrote the shared pricing and formula logic once in Rust and compiled it to WebAssembly, so the TypeScript and Rust codebases stopped drifting apart on the numbers that matter most.

  • Rust
  • WebAssembly
  • TypeScript
  • NestJS
1buy.ai
In progress

Inbound mail agents: anchor, classify, act

An LLM-assisted pipeline that reads every email the fulfilment platform receives, works out which order or shipment it belongs to without trusting the model to decide, routes it to one of 16 plug-in handlers, and dispatches the resulting action through a transactional outbox.

  • Python
  • FastAPI
  • PostgreSQL
  • Microsoft Graph
1buy.ai
In progress

Order-fulfilment backend: purchase order to customs

An event-driven fulfilment service on FastAPI, PostgreSQL and Kafka that carries a purchase order through shipment and customs, with DHL carrier integration and Claude parsing the trade documents.

  • Python
  • FastAPI
  • PostgreSQL
  • Kafka

Writing

Recent writing

Notes from learning in public: databases, concurrency, and the occasional post about this site.

View all

Building this site in public

The site you are reading is a pilot built in an afternoon. This post is the changelog, the decisions, and what is still rough.

Article1 min read#meta#nextjs

Why I am learning Postgres from the inside out

I have shipped on MongoDB for two years. Postgres is now in my daily work, and I decided to learn it internals-first rather than syntax-first. Here is the plan and the reasoning.

Article1 min read#postgres#learning-in-public

Expertise

What I reach for

The tools I ship with every week. The full matrix on the about page is an honest self-rating, including what I am still learning.

Full matrix

Daily driver

How I work

Working principles

Lines from the project write-ups, not a manifesto. Each one cost something to learn.

  1. 01

    Correct under load first, then fast.

  2. 02

    Backpressure is a permit count, not a thread count.

  3. 03

    Facts we already have beat facts a model infers.

  4. 04

    Return nothing when unsure; the gap stays visible.

  5. 05

    Every number verifiable, every status honest.

  6. 06

    One layer deeper than the job requires.

Contact

Let's talk.

Open to conversations about distributed backends and hard infrastructure problems. Email is the fastest way to reach me.

sidharthsingh7111@gmail.comLinkedIn