AI engineer · Dhaka, Bangladesh (UTC+6)

I build LLM tools with the guardrails already in them.

I build LLM systems and the tooling around them, in Python and TypeScript. Three are installable from public registries. One is deployed, monitored and alerting right now. Three of them exist because I measured something and the measurement disagreed with my design.

Available for remote junior and intern AI engineering roles, and for scoped contract builds.

Public distribution channels

Four public checkpoints, each one cleared by somebody else: a registry accepted the package, a marketplace reviewed and listed the action, a platform hosts the Space, and an independent monitor reports the service up.

Approach / 01

What I build

Guardrails, mostly.

Three separate projects where the contribution is the thing that stops something bad happening: a CLI that intercepts destructive Git operations before they execute, a CI action that blocks non-compliant merges, and a daily gate that fails the build when the data stops making sense.

The other half is measurement — evaluation harnesses and query plans that tell you whether a system actually works, rather than whether it looks like it does.

01

Agents that can act, with limits

Tool-calling agents where the interesting part is the interception layer — what the model is not permitted to do. Git Sensei blocks destructive repository operations before they execute rather than warning after.

02

Retrieval over written policy

RAG where the basis for a decision is an authoritative document, not a regular expression. The Data Guardian judges whether support-ticket content is sensitive by retrieving over the written data-governance policy, and logs every redaction to an ES|QL dashboard so the decision can be audited afterwards.

03

Measurement that can disagree with me

Three projects exist because I measured something and the result contradicted the design I had already written. retrieval-eval scored seven retrievers and published three negative results. guardian-analytics built, measured and dropped three candidate indexes. llm-lab disproved its own core hypothesis, then corrected its own headline number when a better measurement contradicted it.

All three, below

Evidence / 01

Shipped work

Eight projects, all public, all licensed. Three install or run from a public registry without cloning anything, and one is deployed right now with a status page you can check.

/01

guardian-analytics

PostgreSQL · Fastify · deployed and operated

Live service · public status page

A five-table PostgreSQL model of a compliance-audit domain, filled by a dependency-free deterministic generator with 201,619 synthetic violations across 18 months. It answers six questions a flat search index cannot: repeat-offender intervals, month-over-month trends, top-N per department, p95 scan duration, a flagged-but-never-actioned anti-join, and cumulative load. Index choices are measured, not assumed — EXPLAIN (ANALYZE, BUFFERS) before and after, medians of five runs, and three candidate indexes built, measured and dropped with the numbers that disqualified them.

Deployed and operated as a read-only API

  • Liveness and readiness endpoints, with structured JSON logs
  • Uptime alerting and a public status page
  • A CI gate asserting all six query counts against the live database on every push
  • A daily job running 26 exact data-quality checks behind a heartbeat dead-man’s switch

All load is synthetic — a scheduled generator, CI and the uptime monitor. No real users.

PostgreSQLFastifyRendermanaged Postgresstructured logging

The interesting part

Both alarms were proven by drill rather than assumed. An induced anomaly fired the alert and recovered. Dropping a measured index regressed the repeat-offender query from 424 ms to 592 ms — its window sort lost the pre-sorted input and spilled 5,144 kB to disk. Diagnosed from the query plan, restored, and written up as a post-mortem.

/02

llm-lab

Exact Mixture-of-Experts inference · measured on commodity hardware · MIT

The core hypothesis was measured and disproved

An exact Mixture-of-Experts inference pipeline, built to prove that a cheap, GPU-less PC — AMD Ryzen 5 5600G (6 cores, no discrete GPU), ~16 GB RAM, PCIe-3 NVMe — could run models far larger than its memory by streaming weights from disk. Careful measurement disproved the premise: the binder is compute and RAM bandwidth, not disk.

What survives

  • A bit-exact MoE oracle and a byte-identity layout proof
  • A provably lossless expert-contiguous repack — 18,432 slices, all byte-for-byte identical before and after
  • Routing traces
  • Pre-registered decision gates — one of which caught a false positive in favour of the outcome I wanted

Streaming here is dormant, not dead: it would bind on a larger MoE or a higher-bandwidth tier. Findings are scoped to this box, this model, these workloads. Every number above traces to a committed command and its output.

llama.cpp / GGUFQwen3-30B-A3B-Q4_K_MPythonquantization and memory-hierarchy analysis

The interesting part

Then a better measurement disproved my own headline number. 4.3 tok/s turned out to be a per-invocation cold-load artifact — each fresh process re-faulted the ~14 GB working set. Warm, sustained, in-process decode is ~9.2 tok/s, and during it the drive sits idle while all six worker threads peg. A prior-art check then closed the follow-on idea on evidence.

/03

Git Sensei

Python CLI · published on PyPI · GPL-3.0

A natural-language Git assistant. You describe the outcome you want; it translates that into shell commands — and a guard layer intercepts destructive repository operations before they execute. Python with the OpenRouter API, packaged for PyPI so it installs with a single pip command.

PythonOpenRouter APIPyPI packaging

The interesting part

The interception is the point, not the translation. “What stops the agent doing damage?” is the hardest question about LLM tool use, and it deserves a mechanism rather than a warning dialog.

/04

Baseline Guardian

GitHub Action · published on the GitHub Marketplace · MIT

Built for the Chrome Baseline Tooling Hackathon

A CI action that scans CSS against MDN Baseline compatibility data, posts an actionable policy report on every pull request, and blocks merges that break web-compatibility policy.

Node.jsTypeScriptGitHub ActionsMDN Baseline data

The interesting part

It is policy as code, in the merge path where it cannot be skipped. Structurally the same thing as an eval gate in an ML pipeline — take an external spec, turn it into a rule a machine enforces, then put the machine somewhere a human can’t wave it through.

/05

SessionSolve

Multimodal debugging agent · deployed on Hugging Face Spaces · MIT

Built for the Gemini 3 Hackathon

Give it a screen recording of a bug and the repository the bug lives in. It uses vision and a long context window to localise the fault, proposes a patch, and generates a Playwright regression test that verifies the fix visually.

PythonStreamlitGemini (vision + long context)Playwright

The interesting part

Most demos stop at “proposes a patch”. This one closes the loop — perceive, localise, act, and then produce evidence the action worked.

/06

The Data Guardian

Privacy agent · MIT

Built for the Elastic Search AI hackathon

Detects and redacts personally identifiable information in live support tickets. It judges sensitivity by retrieving over the written data-governance policy rather than pattern-matching alone, and logs every redaction to an ES|QL dashboard for audit.

Elastic Agent BuilderElastic Cloud ServerlessES|QLKibana + LensRAG

The interesting part

Grounded decisions plus provenance. If you can’t show why something was redacted, you don’t have a compliance tool — you have a filter. The retrieval claims in this design are the ones retrieval-eval went on to test, and partly disprove.

/07

retrieval-eval

Offline retrieval evaluation · three negative results · MIT

Runs locally on ONNX Runtime · the-data-guardian/retrieval-eval

An evaluation harness written to test retrieval claims that The Data Guardian’s design had asserted without a measurement behind them. A 300-document corpus from the public-domain NIST SP 800-53 Rev 5 OSCAL catalog, 36 graded queries across keyword, paraphrase and multi-document shapes, frozen before any retriever ran, and seven retrievers scored on nDCG@10, Recall@10 and MRR@10.

The useful output is the three things that did not work

  • Title boosting came out bit-identical to the baseline on paraphrase, which doubles as evidence that the anti-leakage rule holds.
  • RRF hybrid fusion landed strictly between its two legs on every subset, because rank-only fusion imports a starved lexical candidate list at full weight.
  • Cross-encoder re-ranking was net flat over dense retrieval — 0.622 against 0.623 nDCG@10 — and cost recall, while clearly helping the weaker lexical stage. It scores the best-judged control negative on 24 of 35 queries: domain mis-calibration, not wiring.

Nothing deployed, no users. The point was the measurement.

PythonONNX RuntimenDCG / Recall / MRR

The interesting part

Most portfolios show only what worked. These three results contradicted a design I had already written, which is exactly why they were worth publishing.

/08

Teletext Zero

“Slow web” browser · live demo · GPL-3.0

Renders live news and weather inside a strict 40×24 Teletext grid, with CRT shaders.

TypeScript

The interesting part

The aesthetic isn’t the problem — fitting arbitrary live content into a fixed 40×24 cell budget is. It’s a constraint-satisfaction engine wearing a UI costume.

Approach / 02

Working together

I'm looking for three things, in this order.

  1. 01

    A junior AI/LLM engineering role or internship, fully remote. What I want most from a first job is real users and day-to-day code review.

  2. 02

    Scoped contract builds — a defined deliverable with a defined end. The work I’m best at is turning a manual workflow into a tool that runs on its own.

  3. 03

    Open-source collaboration. I contribute upstream as well as publish. Patches of mine are merged and shipped in an open-source developer CLI I use daily: a regression test across seven document templates, and a rendering feature that started as a one-word layout bug I hit myself. If something I’ve built is useful to you and it’s missing a feature, open an issue and I’ll read it.

Profile / 01

About

Based in
Dhaka, Bangladesh
Publishing since
September 2025
Status
Undergraduate
Work mode
Fully remote

I'm Md. Rafi, a software engineering undergraduate in Dhaka, Bangladesh.

I started shipping LLM tooling in September 2025, and decided early that publishing to a registry — where installation is one command and anyone can read the source — is a different discipline from building a demo. It forces decisions you can skip otherwise: what happens on bad input, what the tool refuses to do, whether a stranger can run it without you in the room.

Four of these eight projects began as hackathon entries. The deadline is a feature: it's the constraint that decides what the project actually is.

I plan to transfer to Universiti Tun Abdul Razak in Kuala Lumpur in late 2026, pending visa. My location changes; my availability doesn't. That's why the work I'm looking for is remote.

“Rafi Automation Systems” is the name I publish my work under. It's a name for the work, not a company with staff.

Record / 01

Credentials

Education

Daffodil International University — Dhaka, Bangladesh

B.Sc. Software Engineering · in progress · first year completed (3 semesters)
Continuing from the first year at Universiti Tun Abdul Razak, Kuala Lumpur (Q4 2026 intake)

Uttara High School and College — Dhaka, Bangladesh

Higher Secondary Certificate (Science) · October 2024 · GPA 4.92 / 5.00

Certifications

Cambridge Linguaskill (English)

Cambridge University Press & Assessment, 2026
Overall 186, CEFR level C1

Learn C Skill Path & Python 3 Course

Codecademy, 2025

Honors

Bonus Blog Prize — Code with Kiro Hackathon

Kiro AI, Devpost, 2025.

Competitor — CodeTrap Programming Contest

DIUSEC, Daffodil International University, 2025 · 5th overall, 4 problems solved

Spoken languages

Bengali

Native

English

Cambridge Linguaskill, overall 186 (CEFR C1)

Technical skills

Languages
Python · TypeScript · JavaScript · C · SQL
AI & LLM
Retrieval-augmented generation · agent architecture · tool calling · prompt engineering · LLM output evaluation · Gemini API · OpenRouter
Search & data
Elasticsearch · ES|QL · Plotly
Infrastructure
GitHub Actions · CI/CD · Playwright · Streamlit · Node.js · React · Next.js · Git