I build systems that hold under load.

Amr Mohamed · Senior Backend Engineer

AWS Certified Solutions Architect – Associate (2026)

Six years of Node.js and NestJS in ad-tech, fintech and healthcare — the systems where a bad night costs real money.

Recent work.

One NestJS backend serving a web app, a mobile app and a desktop importer.

Dentacares

A dental clinic SaaS I built solo. The hard parts were multi-session billing that reconciles to the cent, structured insurance claims, and an Electron tray app that files X-rays to the right patient without anyone touching them.

Full-Stack · NestJS, TypeScript, React, PostgreSQL, Redis, Electron

Case study

Concurrent-booking protection that holds across time zones and overlapping services.

Booklnk

Multi-tenant appointment booking backend for barbershops, gyms and consultants, built from scratch on NestJS and PostgreSQL. I owned the schema, the service layer and the full API surface.

Full-Stack · JavaScript, TypeScript, Node.js, NestJS, Docker, PostgreSQL

Case study

Cut SMS costs 25% across the platform with a URL shortener service.

Kashier

Payment infrastructure at a payments company: WooCommerce plugins used by thousands of merchants, kept compatible with the block editor and HPOS, plus the integration documentation merchants work from.

Full-Stack · PHP, WooCommerce, MySQL

Case study

Cut a 3-minute cron job to 45 seconds and dropped average query time 40%.

Outlier

An edtech platform where the database had become the bottleneck. I profiled the slow paths, rewrote the queries behind the busiest endpoints, and built an account-merge tool that remaps student records across 12+ tables without losing history.

Back-End · Node.js, Express.js, Redis, JavaScript, PostgreSQL, Git

Case study

Indexed 70k+ ICD-10 medical codes into searchable cards.

Umedmi

A patient management platform built from scratch — schema design, API, AWS infrastructure, real-time chat and payment integration. Three years on a production healthcare system.

Full-Stack · TypeScript, JavaScript, Node.js, NestJS, AWS, MongoDB, Git, Redis

Case study

See all projects

My path into backend.

I picked up programming as a hobby in dental school and it quietly took over. Six years later I've shipped backends in ad-tech, fintech, and healthcare — the kind of systems where a bad night means real money or real patients, not a missed sprint.

Most of my work is in Node.js and NestJS. I keep clear boundaries between modules and design the database carefully up front, because the real cost of a system isn't writing it — it's the next engineer trying to change it six months later. Monitoring, CI/CD, and boring, predictable deploys are part of the job, not an afterthought.

I keep one eye on the bill and one on the user. Cutting infra cost, shaving a few hundred milliseconds off a hot path, or deleting a workflow nobody needed — that's the work I actually enjoy.

Work experience.

Senior Backend Engineer

Thunder · Oct 2025 – Present · Remote

Migrated the ad-tracking event pipeline from RabbitMQ to GCP Pub/Sub — now processing ~1M events/day. Chose Pub/Sub over Kafka after weighing operational overhead against our team size.
Designed the core Express.js and PostgreSQL services behind the ad platform, for reliability under peak traffic.
Added retry logic and dead-letter queues to the messaging layer so we don't lose ad events.

Backend Engineer

BookLnk · Jan 2025 – Sep 2025 · Remote

Architected the backend from scratch for a multi-tenant booking platform (barbershops, gyms, consultants) — owned schema, service layer, and the full API surface on NestJS + PostgreSQL.
Implemented concurrent-booking protection with optimistic locking, resolving slot conflicts across time zones and overlapping service durations.
Integrated Kashier for payments: webhook handling, transaction validation and reconciliation.

Integration Engineer

Kashier · Jul 2024 – Jan 2025 · Hybrid · Cairo, Egypt

Maintained WooCommerce payment plugins used by thousands of merchants, keeping them compatible with the block editor and HPOS.
Rewrote the API and plugin documentation that merchants integrate against.
Built a URL shortener service that cut SMS costs across the platform by 25%.

Backend Engineer

Outlier · Sep 2023 – Jun 2024 · Remote

Cut a cron job from 3 minutes to 45 seconds.
Reduced average query time on the highest-traffic endpoints by 40%.
Built a tool to merge duplicate student accounts, remapping relationships across 12+ tables without losing data.

Backend Engineer

UmedMi · Mar 2020 – Aug 2023 · Remote

Built a patient management system: data model, API layer and cloud infrastructure for a platform handling sensitive medical records.
Designed an ICD-10 medical code parsing engine that turned complex diagnostic codes into interactive, searchable cards — cutting clinical lookup time for providers.
Owned AWS production infrastructure (EC2, S3, IAM) with security groups, automated backups, and monitoring for HIPAA-aligned deployments.

Tech stack.

Backend

Node.js, NestJS, Express.js, TypeScript, JavaScript, Java

Frontend

React, Next.js, TypeScript, Tailwind CSS, React Query

Databases

PostgreSQL, MySQL, MongoDB, Redis

Cloud & infra

AWS (EC2, S3, RDS, IAM, VPC, CloudWatch, SQS), GCP, Docker

Messaging

GCP Pub/Sub, RabbitMQ, AWS SQS

CI/CD

GitHub Actions, Bitbucket Pipelines, blue-green deployments

Testing

Jest, Supertest, integration testing, TDD

Architecture

Microservices, event-driven, clean/hexagonal, SOLID, serverless

Certifications.

AWS Certified Solutions Architect – Associate

Amazon Web Services · 2026

Validates expertise in designing distributed systems, cost-optimized architectures, and resilient applications on AWS.

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What people say.

He has very high communication, managerial, and technical skills and is able to carry out his tasks with high efficiency. He is a very talented developer, a fast learner, and highly productive.

Amira Atallah

Team Leader, Science Academy · LinkedIn recommendation · May 2022