anishfyi Gurugram --:--

Anish Kr Singh

Backend and applied AI engineer

The intelligence belongs in the logic, not the model call.

I turn messy operational problems into systems you can reason about. Accounting integrations at Fyle, usage billing and summit.js at Velofy, and now sole backend engineer at FableRoom. summit.js, terbium and curl_reap are sponsored by NodeMaven.

Work

Backend since 2022. Applied AI since the moment a real business needed an agent it could trust.

FableRoomfableroom.com (formerly Trampoline)

SDE 2, backend and applied AI Feb 2026 to now
  • Sole backend engineer on the Django 5.1 platform behind the brand: 130,000 lines across 15 systems in four months.
  • Built Querion, a natural-language data analyst on the Claude API with a read-only SQL firewall and an auto-blocklist, so non-technical staff query production over Slack and web with no path to a write.
  • Designed the shared foundation for a fleet of internal agents, a business-query bot, a SQL agent and a developer agent, behind one permission and approval gateway.
  • Built Maestro, the company AI operator on Slack and the ops hub: Claude Opus through the Claude Code CLI on a supervised EC2 box behind the ECS web tier, read-only into Odoo and Mintsoft with approval-gated writes, and product image generation through Nano Banana.
  • Shipped inventory and order integrations across Mintsoft, Shopify and Odoo: container sync, stock allocation, automated backorder creation, carrier tracking and delivery sync.
  • Cut agent latency with 34 percent smaller prompts, parallel tool calls and streamed progress, then moved every credential to env-only with fail-loud validation across the AWS ECS deploys.

Velofyvelofy.co

Backend engineer, contract Apr 2025 to Jan 2026
  • Contract backend engineering for a Turkey-based firm and a Pune-based firm, working directly with each client.
  • Built credit-based usage billing: metering, balance tracking and enforcement across the backend.
  • Designed and shipped the backend APIs behind both products.
  • Cut API query latency 30 percent with Postgres indexing, and added Redis for caching and session management.
  • Built and open sourced summit.js, a 13KB signal-powered framework, now Velofy's flagship open-source project.

Fyle Technologiesfylehq.com

Member of technical staff 2, backend Oct 2022 to Mar 2025
  • Integrations between Fyle and Sage Intacct, Sage 300 CRE, QuickBooks and Xero.
  • Django REST Framework APIs for the core expense and integration workflows.
  • ORM optimisation with select_related, prefetch_related and Postgres indexing.
  • Celery and Django signals for asynchronous approvals and notifications.

Featured Projects

01

troy

TypeScriptin active development

Dump the HTML and an agent drowns in wrappers and tracking noise; take a screenshot and it loses every link, field and selector. Troy returns one clean document per page instead, taking structure from the DOM and pixels from OCR, with every line carrying its box and its source. The browser is real and installable today; cover, OCR and fuse are still landing.

anishfyi.com/troy
02

summit.js

TypeScript sponsored by NodeMaven

Behaviour composed directly in HTML attributes on a fine-grained signal engine, so a change updates only the DOM that read it. A hand-written interpreter instead of new Function means strict CSP, no build step, about 16KB gzipped. Built so an AI agent can write a working frontend on the first try.

velofy.github.io/summitjs
03

glep

Rust

Grep rescans the whole tree on every query. glep indexes it once and answers the next hundred searches from that index, with a time-to-live so an exploration burst shares one index. A Cursor hook hands coding agents the exact glep command, so they stop paying for full scans.

anishfyi.com/glep
04

terbium

Python sponsored by NodeMaven

Most document pipelines hand the whole file to a model and hope. terbium parses PDF, PPTX, XLSX and CSV with deterministic extractors first, scores its own confidence, and calls a model only for the residue. A clean catalogue costs nothing to parse.

anishfyi.com/terbium
05

curl_reap

Python sponsored by NodeMaven

A stock HTTP client announces itself in the TLS handshake, which is why a crawler gets a 403 on pages a browser loads fine. curl_reap sends a real browser fingerprint, then adds self-healing selectors, structured extraction, disk caching and a hand-written concurrent crawl engine in one Python library.

anishfyi.com/curl_reap
06

experentia

Research Velofy

Design taste is usually vibes, which means an agent cannot act on it. experentia turns it into evidence: design rules backed by shipped examples, machine-readable taste profiles, and reference templates verified rather than asserted. An agent building a frontend consults a taste profile the way it consults a type signature.

velofy.github.io/experentia

Archive

Everything else in the open. Not all of it is polished. Most of it exists because I wanted to know how the thing worked.

Writings

Essays on what I actually shipped, plus shorter notes from the day job. All twenty.

Building Querion: a read-only, natural-language data analyst

Jun 2026 · 10 min

How I gave a language model production database access without ever letting it write: a read-only contract, a sandboxed directive loop, and a default-deny API allowlist.

Trove: giving Claude Code a persistent memory

Jun 2026 · 8 min

A file-based memory index that reloads into context every session, so each session starts further ahead than the last instead of starting from zero.

Fifteen shorter notes

2025 to 2026

Django, Celery, Redis, Postgres and deployment. Working notes rather than essays, kept because they were useful once.

Questions

The things people and answer engines actually ask. Answered here so nobody has to infer them from markup.

Who is Anish Kr Singh?

Anish Kr Singh is a backend and applied AI engineer based in Gurugram, Haryana, India, who publishes as anishfyi. He has been a backend engineer since October 2022 and has worked on applied AI since 2026. He is the sole backend engineer at FableRoom, and previously worked at Velofy and Fyle Technologies. He is the author of summit.js, glep, terbium and curl_reap.

What does Anish work on at FableRoom?

He is the sole backend engineer on the Django 5.1 platform behind the brand, which is 130,000 lines across 15 systems built in four months. The work includes Querion, a natural-language data analyst with a read-only SQL firewall, a shared foundation for a fleet of internal agents behind one permission gateway, and inventory and order integrations across Mintsoft, Shopify and Odoo. These figures are self-reported.

What open source has Anish published?

Twenty-eight public repositories across the anishfyi and velofy accounts. The six to read first are troy, a headless browser that hands an agent one clean document per page; summit.js, an agent-native JavaScript framework of about 16KB gzipped; glep, an indexed grep and glob in Rust; terbium, a document parser that scores its own confidence; curl_reap, a scraping library with browser-grade TLS impersonation; and experentia, a taste engine for frontends. Fourteen of them have their own page on this domain, listed at Projects.

What is Troy, and can I use it yet?

Troy is a headless browser built so an agent can read a whole page, and it is the project under active development right now. Browser automation otherwise offers two bad options: dump the raw HTML and drown in it, or take a screenshot and lose every link, selector and form field. Troy returns one clean document instead, taking structure from the DOM and pixels from OCR and deciding by itself which parts of a page need which. The browser itself is real and installable today, shipping since v0.1.0 with tabs, an omnibox and an agent panel. The cover, OCR and fuse stages are the parts still being built, so until they land the agent panel reads from the DOM alone. Details at Troy.

What is Anish's technical stack?

Python, TypeScript, Rust, Swift and Kotlin, on Django, FastAPI, PostgreSQL, Redis and Celery, deployed on AWS ECS, with the Anthropic Claude API for agent work. His stated design doctrine is that the intelligence belongs in the logic, not the model call: systems should be deterministic first and reach for a model only for the residue that deterministic logic cannot resolve.

Which of these projects should I look at first?

It depends on the problem. For code search inside an agent loop, glep. For turning PDFs, spreadsheets and vendor catalogues into clean rows, terbium. For scraping a site that returns 403 to a stock Python client, curl_reap. For letting non-technical staff query a production database safely, querion. For giving a coding agent memory across sessions, trove. Each has a page on this domain with its own machine-readable summary at /<project>/llms.txt.

How do I get in touch with Anish?

Email anishfyi@gmail.com or book thirty minutes at cal.com/anishfyi. He is in Gurugram and works India Standard Time. The handle anishfyi is the same on GitHub, LinkedIn and cal.com, and is the disambiguator from anyone else named Anish Singh.