Sarmad Gulzar
Verified Expert in Engineering
Back-end Engineer and Developer
Gujrat, Punjab, Pakistan
Toptal member since July 29, 2026
Sarmad is a senior back-end engineer with 7+ years of experience. He specializes in Python, FastAPI, Django, PostgreSQL, Redis, Docker, API design, database design, and maintainable back-end architecture with additional experience integrating LLM-powered features and developing services in Rust. Sarmad builds readable, testable, and reliable software while collaborating closely with product and front-end teams to deliver features quickly without accumulating unnecessary technical debt.
Portfolio
Experience
- Python - 7 years
- PostgreSQL - 5 years
- Docker - 5 years
- Django - 4 years
- Rust - 3 years
- FastAPI - 3 years
- Model Context Protocol (MCP) - 2 years
- Redis - 2 years
Work Experience
Founder & Lead Back-end Engineer
Infinity AI Lab
- Designed, built, and launched multiple SaaS products from concept to production, owning back-end architecture, APIs, databases, infrastructure, and deployment.
- Built scalable asynchronous back-end systems using Python, FastAPI, Django, PostgreSQL, Redis, and cloud infrastructure.
- Led technical product decisions across architecture, data modeling, API design, reliability, performance, and deployment while taking products from initial idea through working SaaS applications.
Senior Back-end Engineer
Triptap
- Built FastAPI back-end services for an AI-powered trip-planning and itinerary-generation platform.
- Designed REST APIs and PostgreSQL schemas for trips, itineraries, user preferences, and AI workflows.
- Integrated LLM-powered functionality with structured input validation, request handling, and response processing.
- Improved back-end reliability, error handling, maintainability, and developer ergonomics.
- Supported Docker-based deployments, cloud infrastructure, production debugging, and operational issues.
- Collaborated with product and front-end engineers to deliver end-to-end features quickly and safely.
Software Development Consultant
Freelance Clients
- Completed 58 freelance projects for international clients, delivering backend development, API integrations, automation solutions, and custom software across approximately 990 billable hours.
- Maintained a 5.0/5.0 average client rating across 44 reviews, demonstrating consistent delivery quality, technical reliability, and effective communication throughout client engagements.
- Designed and developed backend applications and RESTful APIs using three Python frameworks—Django, FastAPI, and Flask—supporting custom business requirements, third-party integrations, and data-driven workflows.
- Built and integrated solutions using external services, including OpenAI, Google Maps, and Companies House APIs, enabling automated data retrieval, processing, and business workflow integration.
- Developed data extraction systems, and workflow automation tools for e-commerce and business operations, reducing dependence on manual processes through custom Python solutions.
Software Engineer
Fielder
- Built and maintained Django back-end systems for a staffing and workforce-management platform.
- Developed scheduling, shift-management, attendance-tracking, and staff-operations workflows.
- Implemented clock-in and clock-out functionality with geofencing-based business rules.
- Designed PostgreSQL models, REST APIs, schema migrations, and back-end workflows.
- Built background jobs, scheduled processes, and task queues using Celery and Redis.
- Refactored existing systems to improve readability, testability, reliability, and long-term maintainability.
Project History
Unpoll — Reliable Webhook Infrastructure for the WhatsApp Agent API
I designed and built the platform end-to-end using Rust, Tokio, Axum, SQLx, and PostgreSQL, focusing on distributed systems reliability, fault tolerance, security, and operational efficiency.
The core architecture separates the REST API, asynchronous polling workers, and webhook delivery workers. I implemented PostgreSQL-backed distributed leases with fencing tokens to coordinate workers, prevent concurrent polling of the same agent, and support crash-safe recovery.
For webhook delivery, I built a durable PostgreSQL-backed job queue with at-least-once delivery semantics, exponential backoff with jitter, worker leases, attempt history, and manual redelivery. Webhooks are authenticated using HMAC-SHA256 signatures, while a hardened HTTP transport provides SSRF protection, connection-time DNS/IP validation, and bounded concurrency.
I deployed the infrastructure on Google Cloud, using Cloud Run, Cloud SQL, Firebase Hosting, and containerized workers with automated CI/CD.
Numa | Business Website and Content Management Platform
I structured the back end around a hexagonal architecture, separating domain models and application use cases from HTTP routes, database persistence, and external integrations. Repository interfaces and dependency injection kept business logic independent of FastAPI and SQLAlchemy, allowing the same workflows to support both REST APIs and the management dashboard.
I implemented business-level tenant isolation, owner and member permissions, session authentication, and explicit publishing controls. I also built image storage integrations for Google Cloud Storage and inquiry notifications via Resend.
For deployment, I containerized the application with Docker and built a GitHub Actions pipeline that runs checks and PostgreSQL integration tests, applies Alembic migrations, and deploys to Google Cloud Run. I also addressed database connection pressure by releasing sessions before image downloads and configuring connection pools alongside deployment scaling limits.
Hndl | Persistent Short Links for Online Handles
https://hndl.toExaim | AI-powered Exam Preparation and Automated Grading Platform
Education
Bachelor's Degree in Electrical Engineering
University of Engineering and Technology (UET) - Taxila, Pakistan
Certifications
Claude Certified Developer - Foundations
Anthropic
Meta Back-end Developer Certificate
Coursera
Skills
Libraries/APIs
REST APIs, Google Maps, OpenAI API, API Development, Back-end APIs, React, SQLAlchemy, Vue, Google Maps API, Django ORM, Node.js, Claude API, SendGrid API, Asyncio, Pydantic
Tools
Claude, Git, Claude Code, Codex, Zapier, SendGrid, Celery, MATLAB, Microsoft Excel, n8n, Terraform, Claude Agent SDK, Pytest, GitHub, BigQuery
Languages
Python, Rust, HTML, SQL, JavaScript, CSS, Simulink, TypeScript
Frameworks
Django, Svelte, OAuth 2, JSON Web Tokens (JWT), Alembic, Flutter, Next.js, Flask
Paradigms
Role-based Access Control (RBAC), Automation, Best Practices, Event-driven Programming, Testing, Refactoring, Model Context Protocol (MCP), Database Design, Dependency Injection, Clean Code, Clean Architecture
Storage
JSON, Google Cloud SQL, Database Migration, PostgreSQL, Amazon S3 (AWS S3), Redis, Databases, Cloud Firestore, Google Cloud Storage
Platforms
Docker, Linux, Google Cloud Platform (GCP), Twilio, AWS Lambda, Cloud Run, Firebase, Amazon Web Services (AWS)
Other
FastAPI, API automation, Documentation, APIs, Web Development, Architecture, Software Architecture, OAuth, Supabase, API Integration, Back-end, OpenAI, Workflow Automation, Cloud, CSV, ChatGPT API, API Design, Agentic Coding, Web Application Design, Agentic AI, Back-end Development, Integration, Third-party APIs, Third-party Integration, Multi-tenant Architecture, Multi-tenant SaaS, Multitenancy, Authentication, Software as a Service (SaaS), SaaS, AI-assisted Development, Serverless, Software Development, Software Development Lifecycle (SDLC), Webhooks, Rest APi, Debugging, Full-stack Development, Attendance Systems, Artificial Intelligence (AI), Large Language Models (LLMs), AI Tools, Full-stack, Dashboard Development, AI Agents, Email, SQLModel, CI/CD Pipelines, Row-level Security (RLS), Anthropic, Front-end Development, Concurrency, Scaling, Axum, Shell Scripting, Version Control, Cloud Hosting, Data Structures, Algorithms, Robotics, Digital Logic, Computer Architecture, Systems Engineering, System Design, OpenAI GPT-4 API, AWS ECS Fargate, Google BigQuery, Looker Studio, JSON REST APIs, Asynchronous REST APIs, AI Security, Prompt Engineering, Context Engineering, Agentic Workflow Design, Google Cloud Build, Cloudflare, Resend, Cloud Storage, Hexagonal Architecture, Domain Modeling, GitHub Actions, Cryptography, Distributed Systems, Reliability Engineering, Database Schema Design, Data Modeling, Data Extraction
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