Taking on select projects

I build systems
that actually
work at scale.

Full stack engineer with 3+ years delivering production-grade software for a hospital in Ireland, a govtech startup, and an enterprise AI platform, not side projects, not tutorials. Real systems. Real stakes.

Z
Zain
Full Stack · React · Node.js · AWS

3+
Years in production
5
Live enterprise products
5+
Tech integrations shipped
Stack layers covered
Domains shipped in
Healthcare (clinical LMS, Ireland)
Government tech (AI-guided marketplace)
AI SaaS (enterprise voice platform)
ReactNext.jsNode.js NestJSLaravelAWS Lambda
Hospital-grade
clinical systems, not just web apps
Serverless
microservices on AWS Lambda at scale
AI + Voice
Twilio, OpenAI & Anthropic integrations
Stripe billing
subscription & revenue logic shipped
What I do

Problems I solve.

Most clients come to me when the complexity of their product has outgrown whoever built v1. Here's where I tend to make the most impact.

Scalable backend architecture
REST APIs, serverless microservices on AWS Lambda, async queues with SQS, and event-driven workflows with EventBridge, designed to handle load, not buckle under it.
🔌
Third-party integrations that don't break
Stripe billing, Twilio voice, OpenAI/Anthropic, CRMs, calendar providers, I've wired all of these into production systems and know where the edge cases hide.
🖥️
Product-quality React frontends
Enterprise-grade UIs in React and Next.js, not just functional, but fast, responsive, and built to be maintained. Pixel precision where it matters, clean architecture throughout.
🔐
Auth, roles & data you can trust
Multi-tenant systems, role-based access, JWT flows, and the kind of data integrity you need when your product handles things that actually matter, like clinical records.

Selected work

Three real products.
Three different domains.

Each one shipped to production. Each one with real users, real constraints, and no room for shortcuts.

🧪
Backend
OCM, Clinical Laboratory System
Cavan General Hospital · Ireland
A hospital-grade LMS handling the full lifecycle of lab operations, sample intake, test processing, clinical reporting, in an environment where data errors have real consequences.
LaravelPHPMySQLREST API
Read case study →
🏛️
Backend
HelloGov, GovTech Marketplace
AI-guided government services platform
A marketplace connecting citizens with government-registered couriers, guided by AI step-by-step so applications don't get rejected. Built the backend systems that made it run.
NestJSNode.jsTypeScriptPostgreSQL
Read case study →
🤖
Full Stack
Thinkrr AI, Enterprise Voice Platform
Conversational AI for enterprise clients
An AI platform powering voice and web agents for enterprise businesses. Shipped billing, Twilio voice, AI copilots, CRM integrations, and a serverless microservices backend on AWS.
ReactNode.jsAWS LambdaStripeTwilio
Read case study →

Tech stack

What's in the toolkit.

Everything here has been used in a real, live, production system, not picked up from a YouTube video the week before.

⚛️ Frontend
React Next.js TypeScript Tailwind CSS Redux Zustand HTML / CSS Responsive UI
⚙️ Backend
Node.js NestJS Laravel PHP REST API Design PostgreSQL MySQL MongoDB
☁️ Cloud & Integrations
AWS Lambda SQS EventBridge Step Functions Stripe Twilio OpenAI API Docker Vercel CI/CD

Process

How I work with clients.

I don't ghost, I don't over-promise, and I don't deliver code that only works on my machine.

01
Scope before sprint
I ask the right questions upfront. Ambiguous requirements are how projects go sideways, I'd rather spend a day scoping than two weeks rebuilding.
02
Async-first, visible progress
You'll always know where things stand. I document decisions, push regular updates, and flag blockers before they become problems.
03
Code that doesn't need babysitting
Clean structure, sensible naming, and logic that the next developer can follow, because messy handoffs are expensive and I won't be the reason for one.
04
Ship, then support
Delivery isn't a disappearing act. I'm available post-launch for questions, fixes, and anything that comes up once real users get their hands on it.

Background

Where I've shipped.

Feb 2025 – Present
Full Stack Engineer (Contract)
Thinkrr AI
Building enterprise AI products using React, Node.js, and a serverless AWS architecture. Delivering features across AI voice agents, Stripe billing, CRM integrations, Twilio telephony, OpenAI & Anthropic integrations, and scalable Lambda-based microservices.
React Node.js AWS Lambda Stripe Twilio OpenAI
Apr 2024 – Feb 2025
Full Stack Developer
Custom Software
Rejoined Custom Software to continue developing enterprise applications for healthcare clients. Built and maintained Laravel backend services, APIs, database solutions, and production features while collaborating closely with cross-functional teams.
Laravel PHP MySQL REST APIs
Sep 2023 – Apr 2024
Backend Developer
Coding Crafts
Developed backend services using Node.js and NestJS for a government technology platform. Built REST APIs, designed PostgreSQL data models, implemented authentication, and contributed to scalable backend architecture.
Node.js NestJS TypeScript PostgreSQL
Jul 2022 – Sep 2023
Backend Developer
Custom Software
Started my professional software engineering career building healthcare applications for Cavan General Hospital, Ireland. Developed Laravel APIs, database models, reporting systems, and business-critical features for a clinical laboratory management system.
Laravel PHP MySQL Healthcare
Fit
I work best with clients who know what they're building.

I'm not the right fit for every project, and I think that's worth being upfront about. The work I do best is for clients who have a real problem, a real product, and want an engineer who'll treat it that way.

You have a defined scope. Exploration is fine, but I work best when there's a clear outcome we're building toward.
You value clean code over fast hacks. I can move quickly, but not at the cost of something you'll have to rewrite in six months.
You communicate. I'm async-friendly and timezone-flexible, but I need a real point of contact, not radio silence for weeks.
You're building something that matters. Healthcare, fintech, AI infrastructure, developer tools, I thrive when the stakes are real.

If this sounds like you,
let's talk.

I take on a limited number of projects at a time. If you have something worth building, reach out, I'll tell you honestly whether I'm the right person for it.

View Upwork Profile →
Usually responds within 24 hours
🧪
Healthcare · Backend · Laravel

OCM, Clinical Laboratory Management System

A hospital-grade LMS built for Cavan General Hospital in Ireland. The kind of system where a bug isn't a user complaint, it's a clinical risk.

Client
Cavan General Hospital, Ireland
My Role
Backend Developer
Stack
Laravel · PHP · MySQL
Domain
Healthcare / Clinical

The context

Clinical laboratories are not forgiving environments. Every sample has a patient behind it. Every result feeds into a clinical decision. OCM was built to manage this entire chain, from the moment a sample arrives at the lab, through every test and result, to the final report in a clinician's hands, for a real hospital in Ireland with real patients.

This wasn't a greenfield toy project. It was a live healthcare system that had to be accurate, auditable, and reliable by default.

The constraint that shaped everything: In a hospital system, there is no "we'll fix it in the next release." Data integrity isn't a feature, it's the baseline. Every piece of backend logic had to be correct the first time.

What I built

  • Designed and developed RESTful APIs in Laravel covering the full lab workflow: sample registration, test assignment, processing stages, and result recording
  • Modelled complex clinical entities, samples, test panels, patients, lab staff, result chains, using Eloquent ORM with schemas built for auditability
  • Implemented role-based access control so lab technicians, doctors, and admin staff could only see and act on what they were authorised to
  • Built reporting endpoints that powered clinical result views consumed by the frontend and, ultimately, clinical staff
  • Applied database transactions, validation layers, and structured error handling throughout, the kind of defensive programming that healthcare requires

Tech stack

Laravel PHP MySQL REST APIs Eloquent ORM RBAC Database Transactions

What this project taught me

Building for healthcare recalibrates your standards permanently. When your APIs are part of a clinical workflow, you stop writing "good enough" code. You write code that's correct, traceable, and that another developer can audit six months later. That standard now applies to everything I build.

🏛️
GovTech · Backend · NestJS

HelloGov, AI-Guided Government Services Marketplace

A marketplace that removes the guesswork from government document applications, connecting citizens with registered couriers and walking them through every step with AI.

Product
HelloGov
My Role
Backend Developer
Stack
NestJS · Node.js · TypeScript
Domain
Government Tech

The problem worth solving

Government applications fail constantly, not because people are careless, but because the process is genuinely confusing. Wrong form, missing document, wrong courier, rejected on a technicality. HelloGov was built to eliminate that friction: match citizens with government-registered couriers, then guide them step by step through the application so it goes through right the first time.

The AI guidance layer was the product's core differentiator. My job was to build the backend that made it possible.

The core engineering challenge: Coordinating a two-sided marketplace, couriers and citizens, while also maintaining the application state that drives AI-guided step-by-step flows. Every piece of backend state had to be consistent, because the AI layer depended on it to be accurate.

What I built

  • Built backend services in NestJS with TypeScript, implementing clean modular architecture following NestJS conventions for long-term maintainability
  • Developed APIs powering the full marketplace flow: courier discovery and matching, order placement, status tracking, and fulfilment management
  • Designed PostgreSQL schemas and wrote queries supporting both marketplace logic and the application tracking state consumed by the AI guidance layer
  • Integrated the backend with the AI guidance system, ensuring application flow state was reliable enough to drive step-by-step user experiences
  • Implemented authentication and access control separating citizen and courier contexts with appropriate permissions for each

Tech stack

NestJS Node.js TypeScript PostgreSQL REST APIs JWT Auth Modular Architecture

What this project taught me

HelloGov was my first deep experience with NestJS in a team environment, building services that needed to be clean enough for other engineers to work in confidently. It also reinforced something important: when the domain involves government processes and real documents, your backend's data consistency isn't just a technical concern, it's what the whole product promise depends on.

🤖
AI SaaS · Full Stack · AWS · React

Thinkrr AI, Enterprise Conversational AI Platform

An enterprise platform for AI-powered voice and web customer engagement, built on a serverless microservices architecture with integrations across Stripe, Twilio, OpenAI, Anthropic, and multiple CRM systems.

Product
Thinkrr AI
My Role
Full Stack Developer
Frontend
React
Backend
Node.js · AWS Lambda · Serverless

What Thinkrr is

Thinkrr AI lets businesses deploy intelligent agents that handle voice calls, web conversations, scheduling, support, and lead qualification, all from one platform. Enterprise clients use it to automate customer interactions at scale while staying connected to their existing CRMs, calendars, and payment systems.

I worked across the full stack: building enterprise UI in React, and contributing to a serverless backend that coordinates a significant amount of moving parts, AI providers, telephony, billing, async workflows, and third-party integrations, simultaneously.

The complexity that made this hard: A Lambda function handling a voice call might need to query a CRM, trigger an EventBridge event, update a PostgreSQL record through the shared data layer, and respond to Twilio, all within a tight latency budget. Getting this right meant understanding the whole system, not just your slice of it.

What I shipped

  • Built AI voice and web copilot experiences, integrating OpenAI and Anthropic APIs with conversation state management for real-time agent interactions
  • Developed end-to-end Stripe subscription billing, plans, upgrades, downgrades, usage-based pricing, and webhook handling for payment events
  • Integrated Twilio for inbound and outbound voice: call routing, telephony event handling, and real-time call flows tied to AI agent logic
  • Built calendar scheduling and booking workflows integrated with calendar providers for enterprise appointment management at scale
  • Implemented CRM integrations including Jobber and other business tools via REST APIs and webhook patterns
  • Designed and developed Lambda services following the team's repository pattern and shared Lambda Layer conventions for the data and utility layers
  • Optimised async workflows using SQS queues, EventBridge rules, and Step Functions for long-running and time-sensitive processes
  • Delivered responsive, enterprise-grade React UI features shipped to real business clients
  • Worked across product, QA, and engineering teams to scope, build, and release production features on schedule

Backend architecture

The backend runs entirely on AWS using the Serverless Framework, with each product domain as an independent service, voice agents, MCP, notifications, and more, sharing infrastructure through Lambda Layers:

AWS Lambda (Node.js ESM) Serverless Framework SQS EventBridge Step Functions Lambda Layers PostgreSQL Repository Pattern

Full tech stack

React Node.js TypeScript AWS Lambda Stripe Twilio OpenAI Anthropic API PostgreSQL SQS EventBridge Step Functions Jobber API

What this project taught me

Thinkrr is the project where full stack stopped meaning "I can do frontend and backend" and started meaning "I understand how every layer of a distributed system affects every other layer." When a voice call, a billing event, an AI response, and a CRM update are all connected, you have to think in systems, and ship accordingly.