Skip to content

U1 · Palestine

Ahmed Salman

Full-Stack Engineer

I build the systems behind the interface — event-driven microservices on Kafka and Kubernetes, wired to the Next.js frontends that drive them.

Open to senior full-stack and backend roles

Get in touchDownload CV
GitHub
asalman-dev
LinkedIn
ahmadgsalman
Email
ahmadsalman327@gmail.com

TP1–TP4 · Measured output

Microservices in production
0+multi-tenant iPaaS

Reachware

Active users on a rebuild
0M+ground-up rewrite

ITG Software

API response
2.2sdown from 2.2s

Emall

Crash rate
−0%sustained over two years

iPhoneAlsham CO

U2Overview

Eight years building software people actually run

I started on Android, maintaining an app with half a million users and spending two years driving its crash rate down by thirty percent. That taught me the part of engineering that only shows up after release — the work that happens when real traffic is already on your code.

Today I'm full-stack at Reachware, building a multi-tenant integration platform: nineteen-plus Node.js and TypeScript services, a Next.js frontend, and an event-driven workflow runtime on Kafka. I move across the whole thing — the React screens, the services behind them, and the infrastructure they run on.

Alongside that I've been a Top Rated freelancer on Upwork since 2020, mostly doing the unglamorous work: making slow things fast, fixing crashes, and finishing features that stalled.

U3Toolchain

What I build with

Core

U3.1

Fluent — daily drivers

  • Node.js
  • TypeScript
  • React.js
  • Next.js
  • Kafka
  • Kubernetes
  • AWS
  • Android

Frontend

U3.2

Interface layer

  • React
  • Next.js
  • Redux
  • MUI
  • Tailwind
  • SCSS
  • JavaScript
  • HTML
  • CSS

Backend

U3.3

Services & ORM

  • Express
  • Nest.js
  • Sequelize
  • Mongoose

Data & Infra

U3.4

Storage, streams, runtime

  • MongoDB
  • Redis
  • Elasticsearch
  • Kafka
  • Docker
  • Kubernetes
  • NGINX

Auth & Access

U3.5

Identity and policy

  • Keycloak
  • Casbin

Mobile

U3.6

Native Android

  • Kotlin
  • Java
  • Google Billing
U4Career

Where I've worked

  1. Reachware

    U4.1

    Full-Stack Web Engineer

    Sep 2023 — Present · Full time

    • Develop and maintain Reachware Studio, a multi-tenant iPaaS of 19+ Node.js/TypeScript microservices with a Next.js frontend, with tenant isolation and RBAC via Keycloak and Casbin.
    • Build and operate the event-driven workflow runtime on Apache Kafka — trigger, orchestrator, mapper, and adaptor microservices backed by MongoDB, Redis, and Elasticsearch, with each pipeline stage scaling independently.
    • Node.js
    • TypeScript
    • Next.js
    • Kafka
    • Kubernetes
    • Keycloak
    • Casbin
    • MongoDB
    • Redis
    • Elasticsearch

  2. Emall

    U4.2

    Full-Stack Web Engineer

    Jan 2023 — Mar 2023 · Project

    • Interfaced with the backend to produce a visually dynamic chart across a range of periods, and optimized a separate API from 2.2s to 0.5s.
    • Integrated Cloudflare and configured it to redirect all HTTP requests to HTTPS.
    • Deployed on Amazon Lightsail with an nginx instance, using PM2 for production builds.
    • Node.js
    • Cloudflare
    • AWS Lightsail
    • NGINX
    • PM2

  3. ITG Software, Inc.

    U4.3

    Android Engineer

    Aug 2021 — Aug 2022 · Full time

    • Fully redesigned and re-engineered a high-traffic application with over 1 million active users, developing a new codebase from scratch and improving performance, scalability, and user experience.
    • Kotlin
    • Java
    • Android

  4. Rider Transportation Solutions

    U4.4

    Android Engineer

    Jun 2019 — Sep 2020 · Part time

    • Worked with developers, managers, and other cross-functional teams to redesign and rebuild the skeleton of the company app.
    • Java
    • Android

  5. iPhoneAlsham CO

    U4.5

    Android Developer

    Jan 2017 — May 2019 · Full time

    • Maintained and optimized an application with over half a million users on the Google Play Store, reducing the crash rate by 30% over two years.
    • Increased revenue and improved user experience by implementing a live-radio recording subscription using Google Billing.
    • Java
    • Android
    • Google Billing

  6. Freelance — Upwork

    U4.6

    Top Rated Freelancer

    Dec 2020 — Present · Ongoing

    • Delivered performance improvements, new features, and crash fixes across client apps with consistently high client satisfaction.
    • Android
    • Node.js
    • React

Islamic University of Gaza

U7

B.Sc. Software Engineering

2014 — 2017 · Palestine

U5Case studies

Systems I've shipped

Reachware Studio

U5.1

Reachware · 2023 — Present

The problem

Integrations between business systems are usually bespoke, brittle, and single-tenant. Studio had to run many customers' workflows on shared infrastructure without letting any tenant see, or slow down, another.

What I built

A multi-tenant iPaaS: 19+ Node.js/TypeScript microservices behind a Next.js frontend, with tenant isolation and role-based access enforced through Keycloak and Casbin. The workflow runtime is event-driven on Apache Kafka — trigger, orchestrator, mapper, and adaptor services each consume and publish their own topics, backed by MongoDB, Redis, and Elasticsearch.

Reachware Studio event-driven workflow runtimeFour microservice stages — trigger, orchestrator, mapper, and adaptor — communicating over an Apache Kafka bus, backed by MongoDB, Redis, and Elasticsearch, with Keycloak and Casbin enforcing tenant isolation and role-based access at the boundary.KEYCLOAK + CASBIN — TENANT ISOLATION, RBACKAFKATriggerlistensOrchestratorroutesMappertransformsAdaptordeliversMongoDBRedisElasticsearch
Each stage consumes and publishes its own topics, so any one of them can be scaled without touching the others.
microservices
19+
runtime stages
4
tenant isolation
Multi
  • Node.js
  • TypeScript
  • Next.js
  • Kafka
  • Kubernetes
  • MongoDB
  • Redis
  • Elasticsearch
  • Keycloak
  • Casbin

Charting & delivery pipeline

U5.2

Emall · 2023

The problem

A reporting endpoint took 2.2 seconds to answer, and the charting view had to stay responsive while spanning arbitrary date ranges. Traffic was also still being served over plain HTTP.

What I built

Rebuilt the chart's data interface with the backend so it stayed fast across every period, then profiled and rewrote the slow endpoint. Put Cloudflare in front of the app and configured a full HTTP-to-HTTPS redirect. Shipped the whole thing to Amazon Lightsail behind nginx, with PM2 managing the production process.

API response
2.2s → 0.5s
traffic on HTTPS
100%
  • Node.js
  • Cloudflare
  • AWS Lightsail
  • NGINX
  • PM2

High-traffic app rebuild

U5.3

ITG Software, Inc. · 2021 — 2022

The problem

An Android application with more than a million active users had accumulated a codebase that could no longer carry new work or scale with its traffic.

What I built

Rewrote it from scratch rather than patching it — a full redesign and re-engineering pass on a new codebase, built on current Android practice.

active users
1M+
rewrite
Ground-up
  • Kotlin
  • Java
  • Android

Live-radio app & subscriptions

U5.4

iPhoneAlsham CO · 2017 — 2019

The problem

A Play Store app with over half a million users was crashing often enough to hurt retention, and had no way to earn from its most-used feature.

What I built

Ran a sustained stability and performance program across two years, then designed and shipped a live-radio recording subscription on Google Billing.

Play Store users
500K+
crash rate
−30%
  • Java
  • Android
  • Google Billing
U6Infrastructure

How I run things in production

Most of my work sits below the interface. I design services around the events they exchange rather than the calls they make, give every stage its own scaling story, and put identity and policy at the service boundary instead of trusting the client. The list below is what I've actually operated, with what I used it for.

Event streaming

N1
  • Apache Kafka

Built and operate a four-stage workflow runtime on Kafka topics where every stage scales on its own.

Containers & orchestration

N2
  • Docker
  • Kubernetes

Run 19+ microservices as independently deployable, independently scaled workloads.

Identity & policy

N3
  • Keycloak
  • Casbin

Tenant isolation and RBAC enforced at the service boundary, not in the UI.

State & search

N4
  • MongoDB
  • Redis
  • Elasticsearch

Backing stores for a live pipeline — durable state, hot cache, and queryable history.

Edge & serving

N5
  • NGINX
  • Cloudflare
  • PM2

Reverse proxy, TLS termination, and process supervision on real deployments.

Cloud

N6
  • AWS
  • Lightsail

Provisioned and shipped production instances, including the deploy path that put them behind HTTPS.

This site is part of the same habit: it builds in CI, ships as a multi-stage container image, and runs as a plain Node process behind a reverse proxy. The Dockerfile and workflow are in the repository.

J1Connector

Get in touch

I'm open to senior full-stack and backend roles. Send a message here, or reach me directly at ahmadsalman327@gmail.com.