Backend Engineer

Summary

Haidar A is a Senior Backend Engineer with over five years of experience building scalable, cloud-native systems using Spring Boot, Node.js, and AWS across CleanTech, SportsTech, and Publishing industries. At Createch IT Solutions, he architected geospatial data pipelines and designed on-demand reporting services for large environmental datasets, optimized distributed caching for faster API performance, and deployed containerized microservices through automated CI/CD pipelines. His backend expertise extends to event-driven systems, Test-Driven Development (TDD) with JUnit, Mockito, and RestAssured, as well as integration testing with Testcontainers. Haidar’s engineering approach emphasizes performance, reliability, and cost efficiency—illustrated by his successful migration of low-traffic services to AWS Lambda for reduced operational costs. He has also built RESTful APIs, implemented messaging queues with RabbitMQ and SQS, and optimized database schemas in PostgreSQL and MongoDB. Beyond backend development, he’s contributed to the developer community as a top-rated Technical Author at Baeldung, publishing over 150 technical articles. His strong foundation in modern backend architectures, automation, and cloud deployments makes him an adaptable engineer capable of delivering robust, production-grade systems.

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Assessment Scores

General Coding and Video Assessment

95%

Great score on Implement an LRU Cache Algorithm, Difficulty Hard

Great score on Find the Length of the Longest Substring Without Repeating Characters. Difficulty Medium

Great score on Rate Limiting in APIs, Difficulty Medium

Average score on Handing API Error, Difficulty Medium

Experience

Createch IT Solutions

Senior Backend Engineer

Full-Time

Jun 2022 — Present

Architect ETL geospatial data pipelines for data ingestion, sanitization, and validation using Spring Boot for large environmental datasets to enable large-scale environmental planning analyses

Design on-demand report services such as carbon footprint report generation from complex spatial datasets

Optimize database queries and implement event-driven distributed caching strategy to cut DB load and boost API response times by ~15% in load tests

Apply TDD with JUnit and Mockito for unit tests and RestAssured for automated API testing of key services; utilize Testcontainers to validate end-to-end integration

Containerize services with Docker and deploy them to EC2 via a GitHub Actions CI/CD pipeline to enable zero-downtime releases

Participate in sprint planning, design decisions, product design, and code reviews in an agile environment

Technologies:

Spring Boot

JUnit

Mockito

Docker

AWS Lambda

Python

FastAPI

PostgreSQL

Redis

Self-Employed

Software Engineer

Freelance

Mar 2021 — Apr 2022

Partnered with international clients to gather requirements and agree on solutions aligned with business goals

Engineered and refactored full-stack solutions using NestJS, Node.js, and AWS

Delivered 8+ tailored software solutions for clients and earned a Top Rated status (4.7/5) on Upwork

Technologies:

NestJS

Node.js

AWS

React

AWS

PostgreSQL

MicroAgility Services

Full-Time

Oct 2020 — Mar 2021

Designed RESTful APIs with Spring Boot with a reusable service layer for a mobile-first U.S. consultation firm

Migrated and refactored core MongoDB schemas to improve data integrity and cut query time by ~20%

Built a push notification microservice using Amazon SQS to boost real-time user engagement

Collaborated remotely with the team, contributed to design decisions, ran code reviews, and wrote documentation

Technologies:

Spring Boot

MongoDB

Amazon SQS

Node.js

Java

KapOnTwo

Full Stack Engineer

Full-Time

Dec 2018 — Aug 2020

Architected and developed a basketball sports analytics platform

Implemented core features for play-by-play stats logging, automated video highlights

Built a worker service to transcode videos into compatible formats that reduced storage costs by 40%

Technologies:

Node.js

React

Baeldung

Technical Author

Full-Time

Jun 2021 — Present

Published 150+ in-depth articles on programming, infrastructure, and Linux, reaching thousands of developers

Increased publishing throughput by 1.5× via research across 2,500+ topics, ranking in the top 5% of contributors

Technologies:

Java

Docker

Kubernetes

Linux

Projects

Formattr

Cross-platform desktop app for indie authors to create structured content for print and e-Ink devices;

Education

Bachelor of Science in Software Engineering

2014 - 2018

University of Swat

Swat, Pakistan