Abdul Umaiz Khan
Verified Expert in Engineering
Full-stack Developer
Karachi, Pakistan
Toptal member since June 16, 2026
Umaiz is a full-stack developer and AI engineer with 7+ years of experience in building scalable web, mobile, and AI-powered applications. His expertise spans LangChain, RAG, FastAPI, Node.js, Flutter, and Angular, with notable work at APPIGMA, Social Champ, Jumppace, and IGI Insurance. Umaiz led cross-functional teams to deliver production-grade AI products and architected cloud-native solutions on AWS.
Portfolio
Experience
- Node.js - 4 years
- Full-stack Development - 4 years
- API Development - 4 years
- Flutter - 4 years
- Express.js - 3 years
- FastAPI - 3 years
- Python - 3 years
- Angular - 2 years
Work Experience
Lead Software Engineer
AppIgma
- Led a 5-developer team building a wellness app with mood tracking, habit planning, and nutrition features.
- Built the mobile app in Flutter and the back end in FastAPI, handling both layers hands-on.
- Developed an AI health profile using OpenAI and a custom Qwen model to generate personalized step, water, and exercise goals.
- Built a chatbot on top of the AI models to guide users through daily health and fitness routines.
- Coded alongside the team while also managing sprint planning and feature delivery.
- Connected AI recommendation outputs to back-end goal-tracking logic for habits, nutrition, and exercise.
Software Architect
Social Champ
- Worked as a software architect for a social media management SaaS covering scheduling, analytics, and team collaboration.
- Designed a microservices architecture with separate services for scheduling, video processing, analytics, and auth.
- Split infrastructure across AWS and GCP to balance cost and scalability across services.
- Set up Jenkins CI/CD pipelines to automate deployments across the microservices.
- Collaborated with a 10-person engineering team on architecture decisions and code reviews.
- Built AI-powered content tools to help users generate and manage posts more efficiently.
- Designed workspace and permission settings so teams could collaborate on content in one place.
Senior Software Engineer
Jumppace
- Delivered custom products for 20+ clients, turning early ideas into working applications.
- Built dating, food delivery, and ride-sharing apps using Flutter, Angular, React, and Node.js, hosted on AWS.
- Integrated geolocation for ride-sharing and delivery apps to support real-time tracking and matching.
- Implemented multiple payment flows, including Stripe, PayPal, and custom bank merchant integrations.
- Worked across mobile and web stacks depending on each client's product requirements.
- Took each project from client requirements through to a fully working, deployed product.
Full-stack Developer
IGI Insurance
- Developed cross-platform mobile applications using Ionic and Flutter, delivering seamless experiences across iOS and Android.
- Built responsive, dynamic web applications using Angular for front-end development within enterprise insurance platforms.
- Developed cross-platform mobile applications using Ionic and Flutter, delivering seamless experiences across iOS and Android.
Project History
Social Champ
https://www.socialchamp.comAs the software architect, I led the end-to-end technical design and development of the platform's core infrastructure. I architected a scalable microservices system using Node.js and FastAPI, ensuring high availability and seamless performance under heavy load. The Angular-based web front end delivered a smooth, responsive experience for thousands of daily active users, while the Flutter mobile app extended the platform's reach across iOS and Android. Cloud infrastructure was strategically distributed across AWS and GCP, enabling fault tolerance, auto-scaling, and efficient resource management. I also defined coding standards, reviewed architecture decisions, and mentored the engineering team throughout the product lifecycle.
Education
Associate's Degree in Computer Science
Metropolitan University Karachi - Karachi, Pakistan
Certifications
AWS Certified Solutions Architect - Associate
Amazon Web Services (AWS)
AWS Certified DevOps Engineer – Professional
Amazon Web Services (AWS)
Skills
Libraries/APIs
Node.js, REST APIs, API Development, Stripe API
Tools
Claude, Claude Code, MongoDB Atlas
Languages
Python, Dart, TypeScript, JavaScript
Frameworks
Flutter, Express.js, Angular, Next.js, React Native, NestJS, Ionic
Paradigms
Mobile Development, Microservices Architecture, Event-driven Architecture
Platforms
Firebase, Amazon Web Services (AWS), iOS, Android, AWS IoT, Google Cloud Platform (GCP), Docker
Storage
MongoDB, Redis, PostgreSQL
Other
FastAPI, Full-stack Development, API Design, API Integration, Full-stack, Architecture, APIs, Prompt Engineering, Debugging, Third-party APIs, Performance, Optimization, LangChain, Retrieval-augmented Generation (RAG), CI/CD Pipelines, Payments, Payment APIs, Agentic AI, Generative Artificial Intelligence (GenAI), Vector Databases, Cloud
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