Zia ur Rehman

Available for remote work with teams worldwide

I turn software into intelligent, AI-powered products.

15+ years building production SaaS, ERP and business platforms — now engineering AI agents, automation and intelligent workflows into real products.

I take products from a whiteboard sketch to a live, multi-tenant system that real businesses depend on. Then I add AI agents that read, decide and act inside those systems, with the guardrails a business needs.

Hire me See what I've built LinkedIn
  • 15+ yearsbuilding production web applications
  • Agentic AILLM agents wired into real business workflows
  • MERN + AWScore stack, from schema to deployment

Expertise

What I do

Agentic AI automation

Multi-step AI agents that plan, call tools and APIs, read your data and take action. I build them into your product or your operations, with human approval where it matters.

LLM agentstool callingRAG over business dataworkflow automationhuman-in-the-loop

SaaS product architecture

Multi-tenant systems with subscriptions, role-based access and multi-company support built in from day one, not added later.

multi-tenancysubscription billingRBACmulti-company

Full-stack development

Hands-on across the whole stack: React and Vue on the front, Node.js and Laravel behind it, and data models built for the real workload.

React / Next.jsNode.js / ExpressVue.jsLaravel

Accounting & ERP systems

Double-entry ledgers, invoicing, purchasing, inventory, production, HR and payroll. Business logic where the numbers have to reconcile.

general ledgerbank reconciliationinventorypayroll

Spreadsheets to web apps

Replacing fragile VBA-driven Excel workbooks with online calculation engines that are faster, shareable and far less error-prone.

calculation engineshierarchical dataprocess automation

Cloud & DevOps

Deploying and running products on AWS with containers and automated pipelines, so releases are routine rather than risky.

EC2 · S3 · LambdaSES · CloudFrontDockerGitHub Actions

Technical leadership

Running the engineering side of a product: milestone planning, code reviews, mentoring, and turning founder ideas into clear requirements.

roadmapsagile / scrumcode reviewmentoring
On integrations: Twilio (WhatsApp & SMS), SendGrid, Stripe, Google Maps and HERE Maps. I've wired all of them into production products, along with plenty of REST and GraphQL APIs.

AI & agents

AI agents that do real work, not just chat

Most businesses don't need another chatbot. They need the repetitive, rules-heavy work that eats their team's day handled reliably. I build AI agents that plug into the systems you already run (accounting, ERP, CRM, WhatsApp, email) and carry tasks through from start to finish.

AI agents & agentic automation

Multi-step agents that plan, call tools and APIs, check their own results, and hand off to a human when confidence is low.

planningtool callingmulti-agentmemory

AI-powered SaaS features

AI integrated directly into your product: smart reports, suggestions, auto-categorisation and natural-language search, scoped per tenant.

AI integrationLLM APIsper-tenant usage

AI document processing & data extraction

Reading invoices, bills, statements, contracts and spreadsheets, extracting clean structured data, and validating it before it reaches your system.

OCR + LLMstructured outputvalidation

RAG systems & AI chatbots

Chatbots and assistants that answer from your own documents and records, with sources cited, on the web, WhatsApp or email.

RAGvector searchcitationsTwilio WhatsApp

AI automation of workflows

Automating repetitive back-office work, such as reconciliation, follow-ups, data entry and approvals, so your team only handles the exceptions.

workflow automationhuman-in-the-loopaudit logs

AI coding & code modernisation

Using AI-assisted engineering to move legacy code, such as old PHP, VBA macros or monoliths, onto a modern stack faster and with test coverage.

legacy migrationrefactoringtest generation
Built for production: structured, schema-validated outputs; approval steps before anything irreversible; audit logs of what each agent did and why; and per-tenant cost and usage limits. The same multi-tenant discipline I bring to SaaS, applied to AI.

Selected work

Two systems I can show end to end

I've delivered SaaS, ERP and logistics platforms for clients across a long career. These are two where I led the product and the architecture, and can walk you through every layer.

eAccountify

SaaS accounting & ERP with AI agents · Lead Developer / Product Owner

A cloud accounting and ERP platform for SMEs, with unlimited companies per subscription. It covers the full financial lifecycle, from the first quote to audited financial statements, and has AI agents that turn the books into answers.

  • Sales and purchases flows: quotes → orders → invoices → receipts, with GST/VAT and credit notes
  • Double-entry engine: chart of accounts, general ledger and journals
  • Bank reconciliation with CSV/OFX import and automatic matching
  • Fixed-asset depreciation, full financial reports, and a payroll-ready HR module

AI agents inside eAccountify

  • Reporting agent: ask "how did sales do this quarter vs last?" and get the P&L, trial balance or sales report filtered and summarised
  • Cash-flow agent: projects upcoming cash position from receivables, payables and recurring bills
  • Receivables agent: builds aged-receivables reports, flags overdue customers and drafts follow-ups
  • Anomaly agent: spots unusual expenses, duplicate bills and out-of-pattern journal entries for review
  • Inventory agent: reports slow-moving stock and suggests reorder levels
  • MERN stack
  • AI agents
  • Redis
  • AWS Lambda
  • S3 · SES
  • Docker
  • CI/CD

PlanABuilding

Engineering calculation SaaS · Lead Software Engineer

A web platform for the pre-engineered buildings industry. It replaced complex VBA-driven Excel workbooks with a dynamic online calculation engine that teams can share and trust.

  • Online calculation engine rebuilding the logic that used to live in spreadsheet macros
  • MongoDB schemas designed for deeply hierarchical business logic and large project datasets
  • One shared platform instead of files emailed between people
  • A significant reduction in manual errors and processing time
  • Node.js
  • Express
  • React
  • MongoDB
  • AWS

Other work includes ERP and HR platforms, a QR-based parking notification product, route optimisation, tour-operator booking, logistics, marketplaces and investor analytics. I'm happy to walk through any of it on a call.

How I work

Software should remove work, not add it

The best systems I've built replaced something painful that people were already doing by hand. Here's one decision that shaped eAccountify.

The problem
Accountants and SME owners often manage several companies. Most tools make them pay for, and log into, a separate account for each one.
The approach
Make multi-tenancy and multi-company support part of the core design: every record scoped to a company, role-based access on top, and one subscription covering them all.
The result
Unlimited companies per subscription, all from one login, without retrofitting the data model later.

End-to-end ownership

From the first whiteboard session to production deployment and beyond.

SaaS-first mindset

Multi-tenancy, subscriptions and scalability are part of the design from day one.

AI where it pays off

Agents go where they remove real work, with validation and human sign-off, not as decoration.

Plain-language communication

Remote and async by default, and I explain technical trade-offs in terms founders can decide on.

Toolkit

Core skills

AI & Agents
AI integration · AI agents / agentic automation · AI chatbots · RAG systems · AI automation · AI-powered SaaS features · AI document processing · AI coding / code modernisation · AI data extraction
Backend
Node.js · Express.js · PHP · Laravel · GraphQL · REST APIs · Microservices
Frontend
React.js · Next.js · Vue.js · Tailwind CSS · Responsive UI/UX · PWA
Languages
JavaScript (ES6+) · TypeScript · PHP · HTML5 · CSS3
Databases
MongoDB · MySQL · PostgreSQL · Redis · Schema design & query optimisation
Cloud & DevOps
AWS (EC2 · S3 · SES · Lambda · CloudFront · Amplify · Route 53) · Docker · CI/CD · GitHub Actions
SaaS & Product
Multi-tenant architecture · Subscription billing · Role-based access · API integrations
Integrations
Twilio (WhatsApp & SMS) · SendGrid · Stripe · Google Maps API · HERE Maps API
Leadership
Technical leadership · Agile · Scrum · Team mentoring · Roadmap planning · Requirement analysis

Contact

Get in touch

Have a SaaS idea, a process you'd like an AI agent to take over, an ERP that's outgrown its spreadsheets, or a product that needs a technical lead? Tell me about it and I'll reply within a day.