Senior Backend & Data Engineer

Hassan Zaib Hayat

Building backend infrastructure that scales — open source, healthcare, and beyond.

PythonDjangoPySparkKafkaHadoopAirflowPostgreSQLRedisAWSDockerTerraform
LinkedInGitHub
hassanzaibhayatske@gmail.comLahore, PakistanOpen to Remote — EU / US / Middle East
Hassan Zaib Hayat — Senior Backend Engineer
Background

About Me

I'm a Senior Backend & Data Engineer with 5+ years of experience building scalable APIs, microservices, and end-to-end data pipelines. My core stack is Python and Django for backend services, with hands-on expertise in big data platforms — including production-grade pipelines processing 285M+ e-commerce clickstream events and 3.2M+ NYC taxi trips using Hadoop, Spark, Kafka, and Airflow with React dashboards.

Currently at Purelogics as Backend Lead, architecting HIPAA-compliant healthcare systems. Previously at Arbisoft for four years, delivering complex product features end-to-end across API design, database schema, and deployment. I hold an M.Phil. in Computer Science from PUCIT with a published research paper on Blockchain performance optimisation, and maintain 4 open-source projects, 2 published on PyPI.

Backend Systems

Django, DRF, FastAPI, GraphQL, Celery, RESTful APIs

Data Engineering

PySpark, Kafka, Hadoop, Airflow, Spark Streaming, Parquet

Cloud & DevOps

AWS, GCP, Docker, Terraform, GitHub Actions, CI/CD

Compliance & Architecture

HIPAA, Microservices, Event-Driven Architecture, Multi-tenancy

Career

Work Experience

Senior Backend Engineer

Backend LeadCurrent

Purelogics · Lahore, Pakistan

  • Architected and developed HIPAA-compliant healthcare backend systems using Django REST Framework, PostgreSQL, Redis, Celery, and Elasticsearch, ensuring secure handling of protected health information (PHI) across all API endpoints.
  • Designed and built optimised RESTful and GraphQL APIs deployed on AWS with Docker, processing large healthcare datasets and supporting real-time clinical workflows.
  • Led a backend sub-team of 3–4 engineers, conducting code reviews, enforcing PEP 8 standards, and mentoring developers on writing clean, reusable, and efficient Django ORM queries.
  • Optimised complex database queries using Django ORM best practices, reducing query execution times and eliminating N+1 query patterns across critical healthcare data pipelines.
  • Established backend coding standards and best practices, reducing code-review turnaround time and improving overall code quality across the team.

Senior Full Stack Engineer

Arbisoft · Lahore, Pakistan

  • Independently owned and delivered the majority of features for a core product, end-to-end from API design through database schema to deployment, demonstrating strong ownership and technical autonomy.
  • Developed and optimised high-throughput RESTful APIs using Django and Django REST Framework, applying ORM best practices to write clean, efficient queries that significantly reduced API response times.
  • Designed scalable database schemas in PostgreSQL and implemented query optimisation techniques including indexing, select_related/prefetch_related, query refactoring, and connection pooling.
  • Integrated third-party services including Stripe (payments), Spotify (media APIs), and Sentry (error monitoring), ensuring reliable and fault-tolerant system integrations.
  • Implemented asynchronous task processing using Celery and Redis, offloading long-running operations and improving system throughput for background jobs and scheduled tasks.
  • Built full-text search functionality using Elasticsearch, enabling fast search across large record sets and significantly improving user experience.
  • Managed CI/CD pipelines using GitHub Actions and Jenkins, automating testing, linting, and deployment workflows to streamline release cycles.
  • Deployed and managed backend infrastructure on AWS (EC2, S3, RDS, Lambda, SQS, ECS, CloudWatch), ensuring high availability, monitoring, and cost-efficient resource utilisation.
  • Collaborated with a cross-functional team of engineers in an Agile/Scrum environment, participating in sprint planning, standups, code reviews, and retrospectives.

Research Assistant

Cloud Lab, PUCIT · Lahore, Pakistan

  • Conducted advanced research on Blockchain technology, designing experiments that increased Hyperledger Fabric transaction throughput by 3–4× through configuration optimisation and network tuning.
  • Authored a published research paper on Blockchain performance optimisation, contributing novel findings to the academic community.
  • Built Blockchain prototypes and simulation environments using Docker, evaluating consensus algorithms and smart contract performance under varying network conditions.

Freelance Software Developer

Remote

  • Delivered full-stack web applications for international clients, specialising in Python/Django backend development, database design, and API integration.
  • Worked with a variety of technologies and frameworks to meet diverse client requirements.
Shipped & On PyPI

Open Source

django-query-doctor

v2.0.0
5,300+ downloads·749 tests·86% coverage·8 analyzers·Django 4.2–6.0

Built QueryTurbo, a 3-phase SQL compilation cache, an AST-based static analyzer for DRF SerializerMethodField N+1 detection at import time, and baseline regression detection with GitHub Actions PR annotations. Zero runtime overhead, async-safe, mypy strict + ruff clean.

pip install django-query-doctor
PythonDjangoAST AnalysisPostgreSQLGitHub Actions
GitHub PyPI Docs

pyteam-skills

v1.0.2
Git-aware·Weighted scoring·Recency decay·1–100 normalized

Python CLI tool mining Git history via PyDriller to generate team skill matrices. Outputs interactive Tailwind CSS dashboards with dark mode and filtering.

pip install pyteam-skills
PythonPyDrillerGit AnalysisTailwind CSSCLI
initscanmatrixdashboard
GitHub PyPI

ecommerce-clickstream-platform

285M Events
14 GB·13 Docker services·5 Spark jobs·4-page React dashboard

End-to-end big data platform processing 285M e-commerce clickstream events through batch and real-time streaming pipelines. PySpark batch jobs, Kafka + Spark Structured Streaming, FastAPI SSE backend, React/TypeScript dashboard, Airflow orchestration, Terraform on AWS and GCP. CI via GitHub Actions.

PySparkKafkaHadoopAirflowFastAPIReactTerraformAWSGCP
Portfolio Project GitHub

nyc-taxi-analytics-platform

3.2M Trips
13 Docker services·3 Airflow DAGs·10+ API endpoints·Real-time streaming

Big data platform processing 3.2M real NYC taxi trips. Hadoop MapReduce for zone aggregation, PySpark for demand/revenue analytics, Kafka + Spark Structured Streaming with 15-minute sliding windows, FastAPI async backend with SSE, React/TypeScript dashboard, Terraform on AWS and GCP.

PySparkKafkaHadoopAirflowFastAPIReactTerraformAWSGCP
Portfolio Project GitHub
Selected Work

Projects

HMAT Language

In Design

Designing HMAT — an AI-native general-purpose programming language. Spec v0.2 covers type system, syntax grammar, and skill architecture.

Language DesignCompiler TheoryAI-native

Healthcare Platform

Production

Backend lead on a HIPAA-compliant multi-tenant healthcare SaaS platform. Owns architecture decisions across audit logging, RBAC, API design, and background task infrastructure.

DjangoPostgreSQLCeleryElasticsearchAWSHIPAA
Professional / Private
Academic Background

Education

M.Phil. Computer Science

PUCIT, Lahore  ·  CGPA 3.33 / 4.0

Research on Blockchain performance optimisation — achieved 3–4× improvement in Hyperledger Fabric transaction throughput.

M.Sc. Computer Science

PUCIT, Lahore  ·  CGPA 3.44 / 4.0

Coursework in advanced algorithms, distributed systems, and database design.

Credentials

Certifications

AWS Certified Data Engineer – Associate (DEA-C01)

Amazon Web Services

AWS Certified Solutions Architect – Associate (SAA-C03)

Amazon Web ServicesIn Progress

Java Spring Framework, Spring Boot & Spring AI

Udemy

Blockchain Specialization

Coursera

Python Django – The Practical Guide

Udemy

React Certification

Udemy

Modern React with Redux

Udemy

The Git and GitHub Bootcamp

Udemy
What I Work With

Technical Skills

Languages

PythonJavaScript (ES6)TypeScriptSQLJavaCC++

Backend

DjangoDjango REST Framework (DRF)FastAPIGraphQL (Graphene)Node.jsCeleryCelery Beat

Data Engineering

Apache Spark (PySpark)Apache KafkaHadoop (MapReduce, HDFS, YARN)Apache AirflowSpark Structured StreamingParquet

Databases

PostgreSQLMySQLRedisMongoDBElasticsearchMinIO (S3-compatible)

Cloud & DevOps

DockerTerraform (AWS + GCP)GitGitHub ActionsJenkinsCI/CDAWS (EC2, S3, RDS, Lambda, SQS, ECS, EMR, MSK, MWAA, Glue, Athena)GCP (Dataproc, Composer, Cloud SQL)Linux

Frontend

ReactTypeScriptTailwind CSSRechartsViteTanStack Query

API & Integration

RESTful API DesignGraphQLServer-Sent Events (SSE)Third-Party Integration (Stripe, Spotify, Sentry)

Testing & Quality

pytestJestmypyruffUnit TestingCode ReviewPEP 8 StandardsTest Coverage Analysis

Architecture & Other

MicroservicesEvent-Driven ArchitectureBatch & Stream ProcessingDatabase DesignQuery OptimizationCachingTask QueuesHIPAA ComplianceAgile/ScrumOpen-Source DevelopmentAI-Assisted Development (Claude Code, GitHub Copilot)
Let's Talk

Get In Touch

Open to backend engineering opportunities and collaborations. Feel free to reach out.

Contact

hassanzaibhayatske@gmail.com
Lahore, Pakistan

Profiles

linkedin.com/in/hassan-zaib-hayatgithub.com/hassanzaibhay