Sabbir MahmudFull-Stack Engineer & Solutions Architect

Backend systemsthat hold under load.

I design and ship distributed backends, real-time message pipelines and the cloud infrastructure under them. Django and Node at the core, React and Next.js on the surface.

See selected workGet in touch
Years shipping production systems
0+
Systems deployed to production
0+
Uptime maintained
0%
Languages in a dubbing pipeline
0+
Dhaka, Bangladesh · Open to new work
01 — Experience

Four years of systems built to stay up.

High-throughput education platforms, real-time restaurant operations and automated media pipelines — each one designed for the day traffic doubles.

  1. Active Questions Base
    0k+
    Routine Sync Accuracy
    0%
    Admin Task Reduction
    0%
    • Architected a multi-repo educational platform composed of Next.js 16 (App Router) client portals, Next.js administrative dashboards, an Expo-powered React Native mobile application (Expo Router & Reanimated), and a Node.js/TypeScript Express API backend.
    • Designed and implemented a scalable database schema using MongoDB and Mongoose ODM, integrating Connect-Mongo session storage, JWT auth security, and custom middleware handlers.
    • Engineered a high-throughput question engine on the mobile app leveraging Shopify Flash-List for virtualized list performance and MathJax/WebView wrappers to dynamically typeset complex math equations.
    • Developed a modular, multi-step exam builder using React Hook Form, Redux Toolkit, and Radix UI dialogs, supported by a backend compilation pipeline utilizing PDFKit and Puppeteer to generate high-fidelity PDF exam prints.
    • Integrated Jodit React WYSIWYG editors and KaTeX math typesetting inside the moderator dashboards, enabling administrators to easily draft, categorize, and audit curriculum-aligned question sheets.

    TypeScript / Next.js / React / React Native / Node.js / Express / MongoDB / Mongoose / Redux Toolkit / Radix UI / MathJax / KaTeX / PDFKit / Puppeteer

    Shikhoni(opens in a new tab)

  2. Client Growth
    0%
    Retention Boost
    0%
    Reduced Losses
    0%
    • Integrated the Otter API aggregation gateway with custom Django polling and webhook systems to sync real-time restaurant orders across multiple providers, enabling 35% client expansion.
    • Implemented real-time bi-directional menu tracking and push notifications using Django Channels, WebSockets, and Redis Pub/Sub, boosting customer retention by 30%.
    • Built a synchronization connector between Clover POS OAuth2 APIs and the local SQL database schema to automate ledger auditing and streamline cash management, reducing revenue leakage by 10%.
    • Optimized background worker pipelines and scheduled tasks using Celery, Redis queue limits, and PostgreSQL query optimization, cutting server overhead by 5%.
    • Developed reactive delivery dispatch maps using React/Redux, Google Maps, and Mapbox APIs with live coordinate interpolation, reducing routing overhead by 10%.

    Python / Django / Django Rest Framework / Django Channels / AWS / Nginx / PostgreSQL / Redis / Celery

    Remote Kitchen Inc(opens in a new tab)

  3. Revenue Contribution
    0%
    Efficiency Increase
    0%
    Languages Dubbed
    0+
    • Architected a secure real-time bidding auction system using Ethereum smart contracts (Web3.js) and Next.js SSR to ensure immutable transaction logs, driving 50% of annual corporate revenue.
    • Integrated global payment flows using Razorpay Webhooks, Stripe Elements, and PCI-compliant Express backend APIs to manage recursive SaaS subscriptions.
    • Engineered multi-threaded Python Celery workers and async Node.js middleware to handle heavy file operations without blocking the event loop, boosting throughput by 35%.
    • Designed an automated translator dispatch algorithm and a collaborative React vetting dashboard with atomic state management (Redux), boosting translation vetting accuracy by 20%.
    • Orchestrated cloud pipeline workflows with speech-to-text (Whisper/Azure), neural translation, and text-to-speech APIs from AWS Polly and Google Cloud to automate video dubbing across 114 languages.

    Python / Django / Django Rest Framework / JavaScript / TypeScript / Next.js / Redux / React Native / AWS / Nginx / PostgreSQL / Redis

    My Next Film(opens in a new tab)
02 — Selected work

Things I've built and shipped.

Open-source libraries, developer tooling and backend systems — each one answering a concrete architectural problem.

6 projects · 3 npm packagesMore on GitHub
01  Custom IDECustom VS Code Build

Black AI IDE (opens github.com in a new tab)

A custom, telemetry-free distribution of VS Code featuring a built-in AI coding assistant and agentic loop engine, optimized for secure and private offline development workflows.

  • Built-in AI coding assistant and agentic loop engine living in the activity bar
  • 100% telemetry-free by default with all tracking endpoints completely patched out
  • Security-hardened build with command filter capabilities and custom branding
  • Automated cross-platform build pipeline (macOS, Linux, Windows) using VSCodium build system
  1. Developer input
  2. Agent loop
  3. Local sandbox
  4. AST patch
Built with VS Code, VSCodium, AI Agent, Electron, TypeScript, Node.js
02  NPM Packagev1.0.3

BDPayments (opens npmjs.com in a new tab)

One API for charges, refunds and lookups across Stripe, SSLCommerz, bKash and Nagad.

  1. Charge request
  2. Provider resolution
  3. Lazy adapter
  4. Normalized callback
Built with Node.js, TypeScript, Stripe, SSLCommerz, bKash, Nagad
03  NPM Packagev1.0.0

BDDeliveries (opens npmjs.com in a new tab)

One API to create, track and cancel parcels across Pathao, Steadfast and Paperfly.

  1. Consignment
  2. Gateway dispatch
  3. Courier webhook
  4. State sync
Built with Node.js, TypeScript, Pathao, Steadfast, Paperfly
04  NPM Package2.5k+ Installs

Express Controller Sets (opens npmjs.com in a new tab)

Validated Express CRUD routes generated straight from a Mongoose model.

  1. Mongoose model
  2. Controller set
  3. Sanitizer
  4. Express routes
Built with Node.js, Express, Mongoose, MongoDB, S3 Uploads
05  Automation ToolActive Tool

Python Advanced Invoice Generator (opens github.com in a new tab)

Jinja2 templates compiled into high-fidelity, multi-currency PDF invoices.

  1. JSON schema
  2. Jinja2 template
  3. wkhtmltopdf
  4. S3 stream
Built with Python, Django, Pdfkit, Jinja2, Wkhtmltopdf
06  Enterprise Solution18+ Stars

ISP Billing System (opens github.com in a new tab)

Billing and network automation for ISPs, wired into Mikrotik RADIUS and three payment gateways.

  1. Mikrotik API
  2. RADIUS profiles
  3. Celery
  4. Auto-reconcile
Built with Python, Django, Mikrotik API, Redis, Celery, PostgreSQL
03 — Principles

Decided before the first line of code.

The constraints I design against, so a system stays predictable, cheap to operate and boring at 3 a.m.

01  Systems reliability99.9% Uptime

Fault Tolerance & Circuit Breaking

Distributed networks fail unpredictably. I design services with localized circuit breakers, exponential backoff retries, and decoupled asynchronous job queues (Celery/Redis) so single-service degradation never cascades into global downtime.

  • Idempotent API endpoint design
  • Redis Pub/Sub & Celery task rate-limiting
  • Dead letter queues for unrecoverable payloads
02  Real-time scale< 80ms P99

High-Concurrency & Event Streams

Handling thousands of concurrent live streams requires non-blocking runtimes. Whether it is bi-directional restaurant dispatch coordinates or dynamic exam syncs, state synchronization is orchestrated via lightweight event loops and WebSockets.

  • Bi-directional WebSockets via Django Channels & Node
  • Stateful connection pooling & memory leak prevention
  • Event-driven coordinate interpolation over Mapbox/Google APIs
03  Data architectureZero Lockup

Query Cost & Schema Integrity

A fast API is worthless if the database locks under peak writes. I profile SQL execution plans, implement composite index coverage, optimize Mongoose schema aggregation pipelines, and enforce strict caching layers with Redis TTL strategies.

  • PostgreSQL index profiling & partition pruning
  • MongoDB document schema normalization
  • Cache-aside and write-through caching invalidation
04  Contract integrity100% Validated

End-to-End Type Safety & Contracts

Fragile interfaces cause runtime crashes. I enforce strict contract boundaries across client and server with TypeScript, OpenAPI schema generators, and schema validation middleware before requests ever reach business handlers.

  • Next.js App Router server/client boundary safety
  • Runtime request validation and payload sanitization
  • Automated TypeScript typing from database schemas
04 — Stack

Tools, grouped by the layer they hold up.

Everything here has run in production under real traffic. Expert: a daily driver. Advanced: shipped to production with confidence.

Languages

Day-to-day, in production

  • PythonExpert

    Async services, Celery pipelines, scripting

  • TypeScriptExpert

    Type-safe client and server business logic

  • JavaScriptExpert

    The runtime underneath all of it

Backend

Where most of my time goes

  • DjangoExpert

    DRF, Channels, ORM tuning, auth

  • Node.jsExpert

    Event-driven APIs, non-blocking workers

  • FastAPIAdvanced

    High-throughput async REST surfaces

  • ExpressExpert

    Routing, middleware, request pipelines

Frontend

Interfaces over those systems

  • ReactExpert

    Component state, data flow, virtualization

  • Next.jsExpert

    App Router, RSC, SSR and caching

  • React NativeAdvanced

    Expo Router, Reanimated, FlashList

Data

Schema design and query cost

  • PostgreSQLExpert

    Indexing, partitioning, transaction control

  • MongoDBExpert

    Document modelling, Mongoose ODM

  • RedisAdvanced

    Pub/Sub, queues, cache invalidation

Infrastructure

Getting it running and keeping it up

  • DockerAdvanced

    Containerized deploys, service isolation

  • NginxExpert

    Reverse proxy, load balancing, TLS

  • AWSAdvanced

    EC2, S3, VPC networking

  • LinuxExpert

    Host configuration and shell automation

  • CI / CDAdvanced

    GitHub Actions, automated release pipelines

05 — Contact

Have a system that needs to hold under load?

Available for distributed backend architecture, high-load API design and senior full-stack work. I usually reply within about four hours.

  • NDA friendly
  • Async or sync
  • Direct technical communication