Backend systems / 2026

Building software that stays useful under pressure.

Backend engineer specializing in Ruby on Rails, Java, Spring Boot, data-intensive systems, and reliable cloud infrastructure.

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Abdur Rahman in a tan jacket
Abdur Rahman / Backend engineer

Current focus

Reliable backend architecture

  • Ruby on Rails
  • Java / Spring Boot
  • Data-intensive systems
  • Cloud infrastructure

Based in Islamabad, Pakistan

01Skills

A practical toolkit for complex systems.

The tools I use to design, ship, and operate backend software across application, data, and infrastructure layers.

Backend

  • Ruby on Rails
  • Java
  • Spring Boot
  • Spring MVC
  • Spring Data JPA
  • Hibernate
  • Spring Security
  • REST APIs

Data & messaging

  • PostgreSQL
  • AWS Aurora
  • Redis
  • Sidekiq
  • Apache Kafka
  • Database design
  • Query optimization
  • Batch processing

Cloud & delivery

  • AWS EC2
  • ECS
  • Fargate
  • S3
  • Lambda
  • CloudWatch
  • Docker
  • GitHub Actions
  • CI/CD
  • Heroku

Frontend

  • React
  • Angular
  • TypeScript
  • JavaScript

Quality & engineering

  • JUnit
  • Mockito
  • Swagger/OpenAPI
  • Prometheus
  • Grafana
  • System design
  • Performance optimization
02Experience

Turning operational problems into dependable systems.

A backend-focused path shaped by production ownership, measurable performance work, and close collaboration across teams.

3 years 6 months

Dec 2022 – May 2026

Islamabad, Pakistan

Software Engineer

Lycus Inc.
  • Built scalable Ruby on Rails backend systems and REST APIs for a legal accounting and reporting SaaS platform supporting 50,000+ requests per day.
  • Built financial data ingestion pipelines processing 100,000+ records per batch, reducing import failures by approximately 85% through validation, retries, and idempotent processing.
  • Designed Sidekiq and Redis workflows that offloaded approximately 40% of synchronous workloads and improved API responsiveness.
  • Optimized PostgreSQL and AWS Aurora through query tuning, indexing, and improved data access patterns, reducing average query execution time by approximately 60%.
  • Owned backend architecture across data modeling, API design, caching, database performance, and third-party integrations.
  • Developed Java and Spring Boot services with secure authentication, documented API contracts, and scalable application workflows.
  • Containerized services with Docker and supported deployments with GitHub Actions, AWS EC2, ECS, Fargate, S3, Lambda, and CloudWatch.

5 months

Mar 2022 – Jul 2022

Islamabad, Pakistan

Associate Software Engineer

DevSinc
  • Developed backend features and RESTful APIs using Ruby on Rails and Java/Spring Boot with maintainable MVC architecture.
  • Designed normalized PostgreSQL schemas for 10+ core business entities supporting scalable application workflows.
  • Supported production deployments on Heroku, including configuration, debugging, troubleshooting, and release validation.
  • Collaborated through Git workflows, peer code reviews, Agile development, debugging, and production support.
03Selected work

Systems designed for the messy middle.

A closer look at the backend, data, and delivery problems I have worked on in production environments.

Backend

Legal accounting SaaS platform

Scalable Rails backend systems and REST APIs for legal accounting and reporting workflows.

  • Ruby on Rails
  • PostgreSQL
  • AWS Aurora
  • REST APIs
Read case study
Data

Financial data ingestion pipelines

High-volume imports with validation, retries, error handling, and idempotent processing.

  • Ruby on Rails
  • Sidekiq
  • Redis
  • PostgreSQL
Read case study
Cloud

Cloud-native Spring services

Secure Spring Boot services packaged and delivered through a practical AWS deployment stack.

  • Java
  • Spring Boot
  • Spring Security
  • Docker
Read case study
04Ways I can help

Clearer systems, calmer operations.

Focused engineering support for teams working through backend architecture, performance, data workflows, and cloud delivery.

01

Backend architecture

Practical architecture guidance for APIs, application boundaries, data models, and maintainable service workflows.

  • Ruby on Rails
  • Java / Spring Boot
  • REST API design
02

Performance and data

Find the bottlenecks that matter and improve query patterns, batch processing, caching, and asynchronous work.

  • PostgreSQL
  • AWS Aurora
  • Redis / Sidekiq
03

Cloud delivery

Improve the path from a tested service to a visible, observable production deployment.

  • Docker
  • AWS ECS / Fargate
  • CI/CD
05Background

The foundations behind the work.

Formal training and certification supporting a career built around production software engineering.

2018 – 2022

Bachelor of Engineering in Computer Engineering

Air University, Islamabad

Certification

AWS Certified Solutions Architect – Associate

AWS

06Contact

Have a system worth making better?

Tell me what you are building, where it is getting difficult, and what a useful next step would look like.

khalil.ahmad1547@gmail.com

Islamabad, Pakistan

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