Software Engineer / Backend & full-stack

Bilal Ahmad

Software Engineer focused on building modern, reliable and scalable web applications.

I build backend and full-stack solutions, from APIs and business logic to responsive web experiences, with a focus on clean architecture, performance and maintainable code.

View selected work Let's talk Download resume

Portrait of Bilal Ahmad — @billypentester
Email
GitHub (opens in a new tab)
LinkedIn (opens in a new tab)

Engineering snapshot

01What I build

Backend and full-stack engineering, end to end.

The kind of work I take on, from the data model and API to the interface people use.

01
Backend & APIs
APIs, business logic and data models that stay maintainable as the rules behind them change.
02
Full-stack applications
React and Next.js applications backed by production APIs, from business requirements to release.
03
Integrations
Connecting products to third-party APIs and SDKs, notification channels and external systems.
04
Production engineering
Scheduled jobs, event-based workflows, documentation and tests, and refactoring legacy code for performance.
05
Security-minded development
Authentication, input validation and API hardening built in from the start, informed by a penetration-testing background.
See it in practiceRead the case studies

02Selected work

Production platforms, and the parts I built.

Ordering, loyalty and healthcare platforms I work on at Simplex. Each case study covers the problem, my contribution and what made it hard. Only publicly shareable details are included.

All projects

01 · Food ordering · Loyalty

KFC Pakistan

Loyalty, scheduled ordering and QR dine-in for KFC Pakistan's ordering platform.

Backend lead at Simplex Technology Solutions

What I built

Configurable loyalty engine with point management, third-party integrations and reporting.
Future ordering so customers can schedule orders within operational hours.
QR code dine-in ordering straight from the customer's phone.

NestJS
Node.js
React
MySQL
Redis

Read the case study Visit live site

02 · Food ordering · Payments

Domino's Pakistan

Digital wallet, rule-based free delivery and a refactored client API for Domino's Pakistan.

Backend lead at Simplex Technology Solutions

What I built

Digital wallet so customers can pay with wallet credits at checkout.
Dynamic free-delivery rules based on time, channel, deals and customer location.
Refactored client-side APIs for structure, validation, documentation, security and performance.

NestJS
Node.js
React
MySQL
GTM

Read the case study Visit live site

03 · Healthcare · Integrations

Hospinizer

Patient authentication, appointment reminders and EMR synchronisation across clinics.

Backend engineer at Simplex Technology Solutions

What I built

Patient authentication and automated push notifications to improve appointment adherence.
EMR systems integrated across clinics through an aggregator engine for appointment synchronisation.

Read the case study

Currently building

Independent work, outside client projects.

Systems I design and build on my own time, end to end.

Funds Grid
In progress
A personal investment and portfolio tracking application, designed and built on my own outside client work.

03Experience

From client projects to owning production backends.

Full timeline

Sep 2023 — Present
3 yrs 2 mos · Lahore, Pakistan
Software Engineer
Simplex Technology Solutions (opens in a new tab)
Backend-focused full-stack engineering on production ordering, loyalty and healthcare platforms.
- Delivered 20+ feature modules from business requirements to production, including third-party integrations and analytical reports.
- Built coupons, discounts, taxation and OTP-based authentication for customer-facing ordering platforms.
+3 more on the experience page
- NestJS
- Node.js
- React
- MySQL
- Redis
- GTM
Case studiesKFC Pakistan Domino's Pakistan Hospinizer
Sep 2022 — Sep 2023
1 yr 1 mo · Remote
MERN Stack Developer
Cache First
Remote client delivery across web apps for global and local clients.
- Built 10+ global and local web apps, including a crypto exchange, e-commerce, SPA and CMS solutions, with 4.5+ client ratings for quality and reliability.
- Designed business-oriented data models, automated database migrations and wrote SQL scripts for analytics, reporting and dashboard integrations.
- MongoDB
- Express
- React
- Node.js
- SQL

04How I build

From requirements to production, and back again.

Engineering principles

01
Understand
Understand requirements, constraints and business rules.
02
Design
Plan architecture, data models and API boundaries.
03
Build
Implement backend, frontend and integrations.
04
Validate
Test functionality, edge cases, security and performance.
05
Ship & Improve
Deploy, monitor, maintain and continuously improve.

05Technical expertise

Tools I reach for, and where I have used them.

Grouped by the work they do. Highlighted tools are the ones I use in production every day; the rest I have shipped with on projects or in earlier roles.

Primary Daily, in productionAdditional Worked with

Languages: TypeScript
JavaScript
SQL
Python
TypeScript across backend and frontend code; SQL for data models, migrations and reporting.
Backend: Node.js
NestJS
Express
GraphQL
RabbitMQ
Kafka
Socket.IO
Production APIs, integrations, scheduled jobs and event-based notifications at Simplex.
Frontend: React
Next.js
Tailwind CSS
Vue
Redux
Zustand
Sass
Client web apps at Cache First and frontend integrations on the Simplex ordering platforms.
Databases: MySQL
Redis
PostgreSQL
MongoDB
Data models, automated migrations and SQL scripts for analytics and reporting.
Infrastructure: Docker
Kubernetes
AWS
Google Cloud
Nginx
Containers, cloud hosting and web serving for deploying and running applications.
Tools: Jenkins
Jest
Vite
GTM
CI pipelines, testing, builds and analytics tracking alongside the application code.