Hello, I'm Abdulkhalek Muhammad

Full-StackSoftware Engineer.

I build high-performance systems and clean user interfaces with a focus on reliability and scalability. My work bridges the gap between complex backend architecture and seamless product experiences using Python, Go, and React.

10+
customers served: 4
production systems: Backend → UI
full-stack delivery

View Work GitHub Download CV

SIGNALING.GO

package signalingtype Hub struct {    mu       sync.RWMutex    sessions map[string]*Session    redis    *redis.Client    pubsub   *redis.PubSub}func (h *Hub) HandleOffer(ctx context.Context, req *OfferRequest) error {    session, err := h.GetOrCreate(ctx, req.RoomID)    if err != nil {        return fmt.Errorf("session: %w", err)    }    return session.Negotiate(ctx, req.SDP)}

Engineering Philosophy

Modular Architecture

I design systems with clear module boundaries and explicit contracts between components. Starting with the data model and working outward ensures every layer has a well-defined responsibility.

Clean Boundaries

Strict module separation, explicit interfaces, and dependency injection for testable, maintainable code.

API Contract First

OpenAPI specs and type-safe contracts before implementation. The interface drives the architecture, not the other way around.

Pragmatic Testing

Focused test coverage on business logic and integration points. Testing what matters, not chasing metrics.

psychology

The Mindset

01. Simplicity First

The best code is the code you don't write. I favor straightforward solutions, proven patterns, and boring technology over complex abstractions. Every line of code is a liability.

02. Own the Full Stack

Understanding both backend systems and frontend experiences leads to better architecture decisions. The best APIs are designed with the consumer in mind.

_tech_stack

System Components

My toolbox is selected for stability and ecosystem maturity. I don't chase trends; I choose tools that solve problems efficiently.

Languages

PythonDjango / FastAPI / Flask

GoBackend / Litestream

TypeScriptNode.js / React

PHPLegacy services

SQLPostgres / MySQL

Backend & APIs

Django / DRFPrimary backend

FastAPIAsync Python

Node.jsNestJS / Fastify / Express

REST / GraphQLAPI design

WebSockets / WebRTCReal-time

Data & Caching

PostgreSQLPrimary store

RedisCache / Pub-Sub / Lua

MongoDBDocument store

MySQLRelational

SQLiteEmbedded / WAL

Cloud & DevOps

AWSEC2 / S3 / RDS

DockerMulti-stage builds

NginxReverse proxy

LinuxUbuntu admin

GitHub ActionsCI/CD

Systems & Architecture

Modular MonolithArchitecture

Celery / asyncioBackground jobs

Redis Lua / Pub-SubAtomicity

OAuth2 / JWT / RBACAuth

PerformanceProfiling / N+1

_experience

Where I've Shipped

Recent commercial and freelance work — the systems behind the wins.

Build and maintain Django + PostgreSQL backends and REST APIs for client web products — schema design, auth flows, Pytest coverage, and Dockerized deployments.
Translate product requirements into reliable services in collaboration with PMs and designers across time zones.

Cut a critical page from 120s to 7s (~16× faster) on a system used by thousands of daily users — profiled hot paths, eliminated N+1 queries, and added strategic Postgres indexes.
Designed a high-throughput real-time location endpoint sustaining 1,000+ req/s by buffering writes through Redis and async-flushing batches to Postgres, keeping write latency low under sustained load.
Extended Litestream (Go) to support encrypted SQLite database and WAL files — learned Go on the job and shipped the modification end-to-end.
Architectural redesign of a legacy monolith — introduced a modular-monolith pattern and reusable boilerplate, cutting tech debt and accelerating subsequent feature delivery.
Designed a custom ASTM-over-TCP protocol for reliable bidirectional communication with lab/medical devices.
Customized OnlyOffice and InvenTree with native modifications and bespoke modules; built and maintained internal tooling in PHP/MySQL.

_selected_works

Production Architecture

view_all_on_github()

BackendE-CommerceProduction

Original Software — Backend

Production Django 5.2 / DRF backend for a digital-license e-commerce platform serving 100k+ customers across 11 domain apps (~21k LOC). Strict HackSoft service / selector / API layering, Celery workers + beat for fulfillment and notifications, PostgreSQL + Redis, full Docker stack, and CI-enforced typing, linting, and tests.

The Challenge

Keeping a fast-growing domain (catalog, cart, orders, payments, coupons, shipping, reviews, resellers, notifications) maintainable without business logic leaking into views or models. Solved by enforcing service / selector boundaries, atomic transactions on every write, optimized selectors with select_related / prefetch_related, and Celery-driven fulfillment for license delivery.

Open SourceTypeScript / Node.js

FluxCore

Discord bot platform and admin dashboard with a graph-based automation engine, encrypted-token RBAC, and a two-process state-sync layer. Designed to run as a single Postgres + two Node processes — no Redis, no extra brokers — so the deploy stays minimal while latency stays sub-second.

The Challenge

Keeping bot and dashboard state coherent without introducing a message broker, while running user-defined action / condition / delay DAGs safely. Solved with a monotonic-cursor Postgres invalidation queue plus a low-latency HTTP push channel, a 13-operator condition evaluator behind a hot in-memory cache, and AES-256-GCM-encrypted OAuth2 tokens with sliding two-tier sessions and hierarchical wildcard permissions.

Real-TimeWebRTC

GoRing

A production-ready WebSocket signaling server for voice calling with Redis-backed state management. Supports horizontal scaling via Redis pub/sub, JWT auth, and atomic session management using Lua scripts.

The Challenge

Ensuring race-condition-safe call state transitions across multiple server instances. Solved using Redis Lua scripts for atomic operations and pub/sub for cross-instance messaging.

Desktop AppC++ / Qt

PriceBell

A cross-platform desktop price tracker that monitors products on Steam, Udemy, Amazon, and custom sources. Background polling, system-tray notifications, alert history, a plugin system (native .so/.dll plus JSON-config sources), and i18n (EN / AR / FR) — all persisted locally in SQLite with versioned migrations.

The Challenge

Designing a long-running native app that polls heterogeneous price sources without blocking the UI, survives restarts, and stays extensible. Solved with a per-product polling scheduler, an IPlugin2 contract for source extensions, and migration-aware SQLite repositories.

AI/MLDesktop App

Transcripty

A voice recorder application with built-in AI transcription powered by OpenAI Whisper. Records audio from any device and converts speech to text with high accuracy.

The Challenge

Integrating real-time audio recording with on-device ML model inference while maintaining a responsive UI. Handled using async processing and efficient audio buffering.

_services

Freelance & Consulting

Web Application Development

Full-stack web applications, REST APIs, database design, authentication, payment integration, deployment pipeline.

6-12 Weeks

Backend Architecture & API Design

System design document, database schema, OpenAPI specification, tech stack recommendation, scalability plan.

2-4 Weeks

Real-Time Systems

WebSocket/WebRTC implementations, signaling servers, real-time data pipelines, pub/sub architectures.

3-6 Weeks

Full-StackSoftware Engineer.

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Languages

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Clean Boundaries

API Contract First

Pragmatic Testing

01. Simplicity First

02. Own the Full Stack

System ComponentslinkCopied

Languages

Backend & APIs

Data & Caching

Cloud & DevOps

Systems & Architecture

Where I've ShippedlinkCopied

Etqan AgencylinkCopied

Native CodelinkCopied

Production ArchitecturelinkCopied

Original Software — BackendlinkCopied

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Tech Stack

FluxCorelinkCopied

The Challenge

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GoRinglinkCopied

The Challenge

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The Challenge

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TranscriptylinkCopied

The Challenge

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Freelance & ConsultinglinkCopied

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Real-Time Systems

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Etqan Agency

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Original Software — Backend

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Modular Architecture

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Where I've Shipped

Etqan Agency

Native Code

Production Architecture

Original Software — Backend

FluxCore

GoRing

PriceBell

Transcripty

Freelance & Consulting