Siraj Abdul Raheem

Senior Full Stack Developer

Islamabad, Pakistan | zlaam.dev@gmail.com | +92 (336) 4684500 https://github.com/mr-zlaam | https://blacksky.norvexiq.com

Summary

Accomplished Senior Full Stack Developer with 5 years of progressive experience specializing in MERN/PERN stack (MongoDB/PostgreSQL, Express.js, React, Node.js) and scalable application architecture. Demonstrated expertise in microservices design, real-time systems, VoIP infrastructure, and cloud infrastructure with a proven track record of delivering high-performance web and mobile applications. Adept at leading technical initiatives, modernizing legacy systems, and implementing robust DevOps practices in Agile environments.

Core Technical Competencies

Backend Development

Node.js Ecosystem: Express.js, Fastify, Nest.js with extensive middleware development and RESTful API design
Microservices Architecture: Event-driven systems using RabbitMQ, message queuing, service discovery, and container orchestration
Real-time Systems: WebSocket implementations with Socket.IO, LiveKit, real-time data synchronization, and push notification systems
API Development: REST API design with OpenAPI/Swagger documentation, rate limiting, and authentication strategies

Frontend Development

React Ecosystem: React 18+, Next.js 14+ with App Router, Server Components, and optimized rendering strategies
State Management: Redux Toolkit, React Context API, Zustand, and TanStack Query for efficient data fetching
UI/UX Development: Tailwind CSS, Shadcn UI, Material-UI, and custom design systems with accessibility compliance
Performance Optimization: Code splitting, lazy loading, bundle optimization, and Core Web Vitals improvement

Mobile Development

React Native: Cross-platform mobile development with CLI, navigation (React Navigation), React Native Expo and native module integration
Mobile Architecture: Clean architecture patterns, offline-first design, and performance optimization for iOS/Android
Mobile DevOps: Play Store deployment, CI/CD for mobile, and automated testing pipelines

Database Management

SQL Databases: PostgreSQL and MySQL with complex query optimization, stored procedures, and database migrations
MongoDB: Advanced query optimization, aggregation pipelines, indexing
In-Memory Databases: Redis for caching strategies, session management, and pub/sub messaging systems
ORM/ODM: Prisma, Drizzle, Mongoose with type-safe queries and database schema management

Cloud & DevOps

AWS Services: EC2 instance management, S3 bucket configuration, RDS administration, Vercel Edge functions
Containerization: Docker container development, Docker Compose for multi-service applications, and image optimization
CI/CD Pipelines: GitHub Actions, automated testing, and deployment strategies

Architecture & Design Patterns

System Design: Microservices vs monolithic architecture decisions, event sourcing, CQRS, and domain-driven design
Security Implementation: JWT authentication, OAuth 2.0, role-based access control, and security best practices
Performance Engineering: Load balancing, database indexing, query optimization, and caching strategies

Professional Experience

Full Stack Developer | Accotech, Islamabad

April 2026 – Present | Technologies: Nest.js, Next.js, TypeScript, PostgreSQL, Prisma, Tailwind CSS, Redis, Docker

Platform Migration & Architecture

Leading the migration of Remindoo — a practice management platform for accounting firms — from a no-code platform to a full code stack using Nest.js for backend and Next.js for frontend
Designing a modular monolith backend architecture with Nest.js, establishing clear service boundaries and dependency injection patterns to replace fragmented no-code workflows
Building a type-safe data access layer with Prisma ORM and PostgreSQL, implementing database schema design, migration strategies, and query optimization from scratch
Architecting the frontend with Next.js App Router, leveraging Server Components, streaming SSR, and incremental static regeneration for optimal page performance
Establishing comprehensive CI/CD pipelines with GitHub Actions for automated testing, linting, type-checking, and deployment workflows

Core Feature Rebuild

Rebuilding task management and workflow automation modules with configurable templates, recurring job scheduling, and automated deadline tracking previously handled by no-code automations
Implementing robust role-based access control (RBAC) system with granular permissions for firm owners, staff accountants, and client users
Developing real-time work-in-progress dashboards with live status updates, workload visualization, and capacity planning indicators
Building secure document management with client portal access, file upload handling, and audit trail logging
Implementing integrated time tracking that captures billable hours within task workflows and routes data directly into invoicing modules

Performance & Infrastructure

Implementing Redis caching layer for frequently accessed data patterns, reducing database query load for repeated operations
Containerizing the full development environment with Docker Compose for consistent local development and streamlined onboarding
Setting up comprehensive error tracking, logging aggregation, and performance monitoring for both frontend and backend services
Conducting code reviews, establishing coding standards, and mentoring team members on best practices for the migration effort

Senior Backend Engineer | Tumarms, Islamabad

October 2025 – March 2026 | Technologies: Node.js, TypeScript, LiveKit, WebRTC, Twilio, Telnyx, Redis, PostgreSQL, Docker

VoIP & Real-time Communication Infrastructure

Architected and built a multi-tenant VoIP backend using LiveKit and WebRTC, enabling high-quality audio/video calling for thousands of concurrent users
Implemented BYOK (Bring Your Own Keys) integration layer, allowing customers to seamlessly connect their existing Twilio and Telnyx accounts to the platform
Designed an automated provisioning system for phone numbers, SIP trunks, and API credentials across multiple telephony providers, reducing manual setup time from hours to minutes
Developed signaling and media server orchestration, ensuring sub-100ms latency and automatic failover for mission-critical voice sessions

AI-Powered Voice Agent System

Built an AI agent framework that answers customer calls, understands intent, and takes real-time actions (account lookup, booking, form filling) using speech-to-text, NLP, and text-to-speech pipelines
Integrated the agent with business logic APIs, enabling it to perform transactions, update records, and escalate to human agents when necessary
Implemented stateful conversation management with Redis, supporting multi-turn dialogues and context-aware responses
Designed fallback and clarification handling, achieving a 75% successful self-service rate in pilot deployments

Backend Infrastructure & BYOK Key Management

Created a secure key management service for storing, rotating, and auditing customer telephony API keys with envelope encryption using AWS KMS
Built a dynamic routing engine that directs calls and messages through the appropriate customer-owned provider account based on real-time health and cost metrics
Developed comprehensive webhook and event relay systems to normalize call events from Twilio and Telnyx into a unified internal format for downstream services
Deployed the entire stack on Dockerized microservices with health checks, logging aggregation, and automated scaling policies

Software Developer | Veevis, Islamabad

April 2025 – September 2025 | Technologies: Node.js, Nest.js, Django, RabbitMQ, Socket.IO, Redis, React Native, AWS, Docker

Microservices Architecture & System Integration

Designed and implemented a unified microservices architecture integrating two disparate systems (Django/PostgreSQL and Nest.js/MongoDB) through event-driven communication
Configured RabbitMQ with multiple exchange types (direct, topic, fanout) and implemented dead-letter queues for message reliability, reducing message loss by 95%
Developed service discovery patterns and API gateway routing for 15+ microservices, improving system scalability and maintainability
Implemented distributed tracing with OpenTelemetry and centralized logging using ELK stack for system monitoring

Real-time Communication System

Engineered a full-duplex WebSocket communication layer using Socket.IO with Redis adapter for horizontal scaling across 5+ server instances
Implemented room-based messaging, presence tracking, and real-time notifications serving 5,000+ concurrent connections
Developed message persistence layer with MongoDB and implemented read receipt functionality with 99.9% reliability
Optimized WebSocket payload compression reducing bandwidth usage by 40% while maintaining real-time performance

Legacy System Modernization

Led TypeScript migration of almost 100,000+ lines of JavaScript code across two legacy codebases, implementing gradual migration strategy
Established comprehensive tsconfig rules, custom ESLint configurations, and automated type checking in CI pipeline
Reduced TypeScript compilation errors from 5,000+ to zero over 3-month period while maintaining backward compatibility
Implemented strict typing patterns and generics, improving code maintainability and catching runtime errors at compile time

React Native Mobile Application Development

Developed complete marketplace application from scratch using React Native CLI with custom native modules for enhanced functionality
Implemented vendor dashboard with inventory management, order processing, and analytics visualization
Integrated Twilio Voice SDK for in-app calling functionality with call recording and voicemail features
Optimized application bundle size by 35% through code splitting and dynamic imports, improving initial load time

Cloud Infrastructure & DevOps

Provisioned AWS infrastructure including EC2 auto-scaling groups, RDS PostgreSQL instances, and S3 buckets for media storage
Implemented CI/CD pipeline with GitHub Actions automating testing, Docker image building, and deployment to ECS clusters
Set up comprehensive monitoring with CloudWatch alerts, SNS notifications, and automated scaling policies

Full Stack Developer | Aldbrook Mortgage, Islamabad

January 2023 – March 2025 | Technologies: React, Node.js, Docker, PostgreSQL, Redis, AWS

Online Code Editor Platform

Developed browser-based code editor with real-time collaboration using Monaco Editor and operational transformation algorithms
Implemented Docker-based code execution environment supporting 30+ programming languages with resource limiting and timeout controls
Designed granular permission system with role-based access control, team management, and audit logging capabilities

Performance Optimization & System Architecture

Optimized React application through code splitting, lazy loading, and memoization, improving Lighthouse performance score from 65 to 92
Implemented server-side rendering with Next.js for critical pages, reducing time-to-interactive by 40% and improving SEO rankings
Developed caching strategy using Redis with cache invalidation patterns, reducing database query load by 70%
Refactored Node.js API layer implementing connection pooling, request batching, and response compression

Third-party API Integration

Integrated multiple document verification APIs (ID scanning, background checks) with retry logic and fallback mechanisms
Implemented Stripe payment processing with subscription management, webhook handling, and automated invoice generation
Built comprehensive error handling with Circuit Breaker pattern, reducing third-party API failure impact by 80%
Developed API rate limiting and throttling middleware protecting against abuse while maintaining service availability

System Reliability & Monitoring

Implemented comprehensive error tracking with Sentry integration and custom error boundaries in React application
Set up automated alerting system with PagerDuty integration for critical system failures reducing mean time to resolution by 50%
Developed health check endpoints and implemented automated recovery procedures for common failure scenarios
Conducted load testing with k6 and Artillery.io identifying and resolving performance bottlenecks

Full Stack Developer | Percy (Remote)

December 2021 – January 2023 | Technologies: Next.js, React, TypeScript, MongoDB, Node.js

Custom CRM Development

Developed multi-tenant CRM platform supporting 50+ business clients with customizable workflows and data models
Implemented real-time dashboard with WebSocket connections for live updates of sales pipelines and customer activities
Built advanced reporting module with MongoDB aggregation pipeline processing millions of records for analytics
Designed flexible data model supporting custom fields, relationships, and business rule configurations

Property Management System

Created comprehensive property management CRM with lease tracking, maintenance request handling, and automated notifications
Implemented document management system with version control, electronic signatures, and automated document generation
Developed role-based access control with fine-grained permissions for property managers, tenants, and maintenance staff
Integrated calendar scheduling for property viewings with automated reminders and conflict detection

Internal Tool Development

Built logistics management tool integrating with existing ERP systems through custom API adapters and webhook listeners
Implemented real-time order tracking with mapping integration, delivery status updates, and automated customer notifications
Developed inventory management module with barcode scanning support and stock level predictions using historical data
Created data synchronization engine ensuring consistency across multiple external systems with conflict resolution

Frontend Developer | Fiverr (Remote)

May 2021 – October 2021 | Technologies: React, Next.js, Tailwind CSS, Figma, WordPress

Marketing Website Development

Developed 20+ responsive marketing websites with mobile-first approach and progressive enhancement strategies
Built interactive UI components with Framer Motion animations and gesture-based interactions for enhanced user experience
Optimized websites for Core Web Vitals achieving 90+ scores on Lighthouse audits for all delivered projects

E-commerce & Booking Systems

Developed booking platform with calendar integration, time slot management, and automated confirmation systems
Built e-commerce storefronts with shopping cart functionality, wishlist management, and secure checkout processes
Implemented product configurators with real-time price calculation and 3D product visualization for enhanced shopping experience
Integrated payment gateways (Stripe, PayPal) with PCI DSS compliance and fraud detection mechanisms

Performance & SEO Optimization

Implemented advanced image optimization techniques using next/image, WebP format conversion, and responsive image sizing
Developed custom SEO components with structured data markup, Open Graph tags, and Twitter card integration

Technical Projects

Real-time Marketplace Mobile Application A comprehensive B2C marketplace connecting customers with local vendors

Architecture: React Native with Node.js backend, MongoDB database, Redis cache, and Socket.IO for real-time features
Key Features: Vendor dashboard with inventory management, real-time order tracking, in-app messaging, and review system
Payment Integration: Stripe Connect for marketplace payments, Polar.sh for subscription management, and automated payout system
Performance: Achieved 60fps smooth scrolling for product listings and sub-2-second initial load time through code optimization
Scale: Designed to support 50,000+ monthly active users with horizontal scaling strategies and database sharding plans

Microservices Unification Project Migration from monolithic Django application to microservices architecture

Migration Strategy: Strangler Fig pattern implementation with parallel run of old and new systems during transition
Event Bus: RabbitMQ with topic exchanges for service communication and deadletter queues for failed message handling
Database Strategy: Polyglot persistence with PostgreSQL for transactional data and MongoDB for document storage
Monitoring: Distributed tracing with Jaeger, centralized logging with ELK stack, and metrics collection with Prometheus
Results: 40% reduction in deployment failures, 60% improvement in developer onboarding time, and 30% reduction in incident resolution time

Personal Blog Platform (DevSouls) Self-hosted technical blog with custom CMS and advanced features

Technology Stack: Next.js 14 with App Router, React Server Components, Tailwind CSS, and PostgreSQL
CMS Features: WYSIWYG editor with Markdown support, draft/publish workflow, scheduled posts, and version history
Performance: 90+ Lighthouse scores achieved through SSG (Static Site Generation) and ISR (Incremental Static Regeneration)
Advanced Features: Syntax highlighting with Shiki, dark/light mode theming, full-text search, and newsletter integration
Infrastructure: Hosted on Vercel with automated deployments, Cloudflare CDN, and MongoDB Atlas database

Professional Development

Technical Blog & Publications

DevOps Blogs: Regular publications on system design, React patterns, Node.js optimization, and database performance
Open Source Contributions: Developed and maintaining the tabcut tui which is used to convert website into searchable desktop applications
Achievements: Successfully merged a pull request in wails which is cross platform desktop application framework

Continuous Learning

Current Focus: Edge computing with Cloudflare Workers, advanced VoIP architectures.
Learning Methodology: Hands-on project-based learning, contributing to open source, and continuous code review practice
Mentorship: Regular code reviews and technical guidance for junior developers focusing on best practices and architecture

Technical Philosophy

Clean Code Advocate: Emphasis on readable, maintainable code with comprehensive documentation and consistent patterns
Testing First Approach: Implementation of Test-Driven Development (TDD) for critical business logic and integration testing for APIs
Performance Conscious: Continuous profiling and optimization with a focus on user experience and resource efficiency
Security Mindset: Proactive security practices including dependency auditing, input validation, and regular security reviews
Collaborative Development: Strong believer in pair programming, code reviews, and knowledge sharing within development teams

Languages

English: Professional Proficiency (Technical documentation, client communication, team collaboration)
Urdu: Native Speaker (Fluent in technical and business conversations)
German: Learning

Resume

Professional Resume

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