Open to Software / Backend / DevOps / AI Engineering conversations

Badda, Dhaka, BangladeshAsia/Dhaka (UTC+6)

Md. Musfiqur
Rahaman

I work as aFull Stack Software Engineer

Roles: Full Stack Software Engineer, Backend Engineer, AI Engineer, DevOps Engineer, Software Engineer.

I design the systems underneath the product - multi-tenant SaaS platforms, distributed crawlers, streaming pipelines and the AI layers on top of them - and I stay responsible for them all the way to the container running in production.

3+
years shipping production systems
10k+
daily active users supported
4
platforms designed end to end
5
engineering disciplines covered
Md. Musfiqur Rahaman, Full Stack Software Engineer, working on a laptop
fig 01 - the engineer
  • Full StackDjango · DRF · FastAPI
  • BackendPython · Django · DRF
  • AILangChain · LangGraph · CrewAI
  • DevOpsDocker · GitHub Actions · Traefik
  • EngineeringPython · TypeScript · C++

Core stack: Python, Django, FastAPI, PostgreSQL, Redis Streams, Celery, pgvector, Docker, Traefik, AWS, Next.js, React Native, LangGraph, Scrapy, Playwright, Prometheus, Grafana, Cloudflare, PgBouncer, WebSocket.

01 / Capability console

Five roles, one engineer

Job titles slice the same work differently. Pick the lens you are hiring for - the diagram, the evidence and the stack all re-focus around it.

Live systemA request through the stack I build, operate and debug
Architecture diagram of the systems Md. Musfiqur Rahaman buildsClients reach a Cloudflare and Traefik edge, which routes to a Django and FastAPI API. The API uses a Redis cache and PgBouncer pool, and enqueues onto a Redis Streams plane feeding Scrapy and Playwright workers and an LLM and embedding model layer. Results are committed to PostgreSQL with schema-per-tenant isolation and to a pgvector semantic index, with Prometheus and Grafana observing the workers.ClientsWeb · Mobile · APIEdgeCloudflare · TraefikAPIDjango · FastAPICache & LocksRedis · PgBouncerStream PlaneStreams · CeleryWorkersScrapy · PlaywrightModel LayerLLM · BGE-M3PostgreSQLschema-per-tenantpgvectorsemantic searchObservabilityPrometheus · Grafana

Hover a nodeEach block is something I have built, broken and fixed in production.

One person, the whole vertical slice.

I take a feature from an ambiguous requirement to a deployed, observable slice - schema, API, UI state, background jobs and the release that carries it. Three products in production, two of them multi-tenant SaaS with a web app and a mobile client on the same API.

  • 3production platforms owned end to end
  • Web + Mobileclients served from one Django API
  • 10k+daily active users supported
  • Django
  • DRF
  • FastAPI
  • React
  • Next.js
  • React Native
  • TypeScript
  • PostgreSQL
  • WebSocket
  • 01

    Product-shaped API design

    RESTful resources modelled on the domain, not the ORM - versioned, paginated, permission-aware, and documented well enough that the frontend team never has to read my code.

  • 02

    React & Next.js front ends on my own contracts

    Dashboards, onboarding flows and admin surfaces in React, Next.js and React Native, wired to WebSocket channels for live state instead of polling.

  • 03

    Requirement → architecture → delivery

    I sit in the requirements conversation, translate it into a data model and a delivery plan, then own it end to end. That loop is why I lead junior engineers today.

Correctness under concurrency is the whole job.

Most of my hardest work lives below the API: lease-based work queues, at-least-once stream processing, schema-per-tenant isolation, and the transactional edges where those meet. I reach for Postgres primitives before I reach for another service.

  • SKIP LOCKEDlease-based frontier, no external queue
  • 4-stagededuplication pipeline that short-circuits
  • Schema/tenantisolation with custom domains
  • Python
  • Django
  • DRF
  • FastAPI
  • PostgreSQL
  • Redis Streams
  • Celery
  • RabbitMQ
  • pgvector
  • WebSocket
  • 01

    Distributed work coordination

    A crash-safe URL frontier on PostgreSQL using FOR UPDATE SKIP LOCKED - priority scheduling, exponential backoff, lease expiry and reaping, so a worker dying mid-fetch costs one lease instead of the queue.

  • 02

    At-least-once messaging that actually holds

    Redis Streams with consumer groups, delayed retries, dead-letter queues and stale-message reclaim across cleaning → LLM → embedding stages. Idempotent handlers, because at-least-once means duplicates are a certainty.

  • 03

    Multi-tenant data isolation

    Schema-per-tenant Postgres with custom domains, plus branch-level scoping inside each tenant and RBAC that resolves against plan, role and resource together.

  • 04

    Integration surface

    SSLCommerz, Stripe, Twilio, Google OAuth, AWS SES webhooks and ZKTeco biometric hardware - each behind an interface so the vendor stays swappable.

LLMs are unreliable subsystems. I engineer around that.

My NLP background is academic - a Bengali↔English word alignment thesis on multilingual BERT - but my LLM work is operational: schema-validated extraction, provider fallback, cost tracking, versioned embeddings and semantic search that has to answer in production latency.

  • BGE-M3versioned embeddings + pgvector search
  • Bangla + ENmultilingual extraction pipeline
  • Geminiagentic contact management
  • LangChain
  • LangGraph
  • CrewAI
  • Gemini API
  • Ollama
  • BGE-M3
  • pgvector
  • Scikit-learn
  • Pandas
  • NumPy
  • 01

    Schema-validated extraction

    Every model call returns against a declared schema. Invalid output is a retry with repair context, not a 500 - and never an unchecked write to the database.

  • 02

    Provider fallback & cost accounting

    Multi-provider routing with automatic failover and per-call token/cost tracking, so a rate limit degrades quality instead of taking the pipeline down.

  • 03

    Semantic search on pgvector

    Versioned BGE-M3 embeddings served through pgvector, with SimHash banding in front so the expensive semantic comparison only runs on genuine near-duplicates.

  • 04

    Agentic interfaces with guardrails

    Gemini-powered contact management driven by natural language and voice, where the agent proposes structured operations and the application layer validates and executes them.

  • 05

    Multilingual by design

    Bangla and English through the same pipeline - tokenisation, dedup thresholds and embeddings all chosen to survive script and morphology differences.

If I built it, I can deploy it, watch it and roll it back.

I own the path from a merged commit to a running container behind Traefik and Cloudflare - multi-tenant provisioning included. Zero-downtime is a deployment property I design for, not a thing I hope for.

  • Zero-downtimedeploys behind Traefik + Nginx
  • Multi-tenantCI/CD provisioning pipelines
  • Prometheusmetrics on every pipeline stage
  • Docker
  • GitHub Actions
  • Traefik
  • Nginx
  • Cloudflare
  • AWS
  • Redis
  • PgBouncer
  • Prometheus
  • Grafana
  • Linux
  • Bash
  • 01

    Multi-tenant CI/CD

    GitHub Actions pipelines that provision, migrate and release per tenant across VPS, AWS and other cloud targets - so onboarding a customer is a pipeline run, not an afternoon.

  • 02

    Zero-downtime releases

    Rolling container swaps behind Traefik and Nginx with health gating, so a bad build never becomes a bad request.

  • 03

    Capacity engineering

    PgBouncer for connection pressure, Redis for read amplification and hot state, and query-level work before hardware - 10k+ DAU held without over-provisioning.

  • 04

    Observability

    Prometheus and Grafana wired to the queue depths and stage latencies that actually predict incidents.

  • 05

    Release automation for packages

    Tag-driven semantic versioning with generated changelogs, publishing to PyPI, GitHub Packages and Docker Hub from one workflow.

The part that outlives the sprint.

Reusable abstractions, written-down architecture, tests where they earn their keep, and mentoring so decisions survive me. A Master's in IT alongside full-time delivery, and an open-source package on PyPI that forced me to take versioning seriously.

  • PyPIpublished open-source package
  • Mentoringjunior engineers across two companies
  • Master'sin IT, University of Dhaka
  • Python
  • TypeScript
  • C++
  • Git
  • TDD
  • Agile
  • SDLC
  • Poetry
  • Jira
  • GitHub Projects
  • 01

    Abstractions that get reused

    Shared components and common layers extracted across projects - the reason feature three in a codebase costs less than feature one.

  • 02

    Technical leadership

    Leading junior engineers, reviewing designs before code, and running knowledge-sharing so the architecture lives in more than one head.

  • 03

    Documentation as infrastructure

    Architecture docs and decision records maintained alongside the code - onboarding time is a measurable engineering output.

  • 04

    Open source discipline

    Data Preprocessors on PyPI: semantic versioning, automated changelogs, reproducible Poetry builds, published to three registries.

02 / Selected work

Systems, not screenshots

Platforms where the interesting part was never the UI. Each case study is written the way I would explain it in a design review.

Read the Sortorium case study
Full Stacklive2025 - Present

Sortorium

Multi-tenant POS and ERP SaaS with an offline-first desktop till that keeps selling when the internet does not.

  • Schema/tenantPostgreSQL isolation
  • Offline-firstTauri desktop till
  • Idempotentcheckout replay
  • Python
  • Django
  • DRF
  • PostgreSQL
  • django-tenants
  • +8
Read the case studyLiveBackendFrontendDesktop
Read the FitsSort case study
Full Stacklive2024 - Present

FitsSort

Multi-tenant, multi-branch SaaS for health and fitness businesses - web, mobile and turnstile.

  • 10k+daily active users
  • 1 schemaper tenant
  • 3clients on one API
  • Python
  • Django
  • DRF
  • PostgreSQL
  • React
  • +9
Read the ECamp case study
AIlive2025 - Present

ECamp

Agentic multi-tenant SaaS for bulk email campaigns and deliverability intelligence.

  • 2interchangeable providers
  • 3-layerrate limiting
  • Pause/Resumemid-campaign
  • Python
  • Django
  • DRF
  • Celery
  • Redis
  • +9
Read the case studySourceLive
Read the ZKTeco LAN Agent case study
DevOpsmaintained2025 - Present

ZKTeco LAN Agent

A LAN-side bridge that makes non-ADMS biometric terminals look like cloud-capable ones.

  • Non-ADMSdevices made cloud-capable
  • 1 pathserver-side ingest
  • At-least-oncepunch delivery
  • Python
  • Poetry
  • PyPI
  • ZKTeco SDK
  • ADMS HTTP
  • +4
Read the case studySourcePyPI
03 / Track record

Where the experience came from

Four years climbing the same ladder from a different rung each time - intern, associate, engineer, senior.

Currently

Senior Full Stack Software Engineer

TechForing Ltd.Jan 2026 - Present

Technical leadership on a multi-tenant SaaS platform: breaking a monolith into services, automating tenant provisioning, and bringing AI into the internal development loop.

  • Provided technical leadership to junior engineers and drove delivery of scalable SaaS platform capabilities.
  • Migrated legacy monoliths into modular microservices, improving reusability, scalability and maintainability.
  • Integrated AI-driven workflows into internal systems, accelerating development and improving team productivity.
Full résumé
  1. Full Stack Software Engineer

    Jan 2025 - Dec 2025

    TechForing Ltd.

    Owned the communication and attendance surfaces of the product line, plus the third-party integrations everything else depended on.

  2. Software Engineer

    May 2024 - Dec 2024

    Nimusoft Technologies Ltd.

    Moved from executing tickets to shaping systems - requirements with leadership, architecture decisions, and end-to-end ownership across several products.

  3. Associate Software Engineer

    Jan 2024 - Apr 2024

    Nimusoft Technologies Ltd.

    Django application work with a deliberate bias toward shared, reusable building blocks.

  4. Software Engineer Intern

    Jul 2023 - Dec 2023

    NSU StartUps Next

    Built the incubator's own platform while advising the startups inside it - a fast lesson in shipping against requirements that change weekly.

04 / Writing

Notes from inside the systems

Long-form engineering write-ups on the decisions that actually mattered - concurrency, isolation, delivery guarantees and where LLMs belong.

Read Selling With the Wi-Fi Down: An Offline-First POS in Tauri 2.0
Full stack12 min

Selling With the Wi-Fi Down: An Offline-First POS in Tauri 2.0

A till that stops working when the internet does is a till that loses money. Here is the outbox-plus-idempotency contract that lets a Tauri desktop POS sell offline and replay safely into a Django backend - without double-charging anyone.

  • Tauri
  • React
  • SQLite
  • Django
Read
Read Decomposing a Monolith Without a Rewrite
Architecture10 min

Decomposing a Monolith Without a Rewrite

Seams before services. How to extract modular services from a legacy monolith incrementally - with the data ownership rule, the strangler pattern, and an honest list of what you give up the moment a function call becomes a network call.

  • Architecture
  • Microservices
  • Django
  • Refactoring
Read
Read Leases Over Locks: A Crash-Safe Work Queue in PostgreSQL
Distributed systems9 min

Leases Over Locks: A Crash-Safe Work Queue in PostgreSQL

How FOR UPDATE SKIP LOCKED plus expiring leases gives you a distributed, crash-safe work queue without adding a broker to your architecture - with the reaper, backoff and priority scheduling that make it production-grade.

  • PostgreSQL
  • Distributed Systems
  • Queues
  • Python
Read
Open to work

If you are building something that has to stay up, let's talk.

Senior backend, platform, or AI engineering - full time or contract. I reply to everything, usually within a day.

Based in
Badda, Dhaka, Bangladesh
Timezone
Asia/Dhaka (UTC+6)
Working with
Distributed teams across time zones
Languages
English, Bangla