CASE STUDY · Enterprise SaaS & AI

Build modern digital services around the systems your business already relies on.

A production-delivered platform connecting web, mobile, e-commerce, AI agents and enterprise systems through a modular architecture.

Discuss your connected platform

Technical ownership: Itzhak Shaul · Architecture & hands-on development
Engagement: Selected freelance project · Client identity confidential
Core technologies: NestJS · FastAPI · Next.js · PostgreSQL / Supabase · n8n · Make · Zapier

A new customer experience should not require abandoning the systems that keep your business running. This production-delivered platform combines modern web and mobile channels, commerce, AI and automation with the enterprise data already in place.

A strong fit for: Product teams and established businesses building a connected SaaS platform across customer channels and existing enterprise systems.

The business challenge

The platform had to support modern customer channels and AI capabilities while integrating with existing AS/400, Oracle and SQL Server systems. Tenant boundaries, reliable automation and controlled delivery mattered as much as the feature set.

My responsibility

As architect and lead developer, I specified, built and delivered the platform to production, covering application architecture, integrations, AI services and delivery infrastructure.

How the system fits together

Simplified workflow illustrating the delivered capabilities.

Web, mobile & commerce
APIs & permissions
AI & automation
Enterprise systems

What I built

A connected product foundation

Multi-tenancy, permissions, subscriptions and billing, with REST, GraphQL and WebSocket interfaces.

Practical AI agents

Per-tenant RAG, tool calling, automatic fallback between model providers, prompt-injection guardrails and idempotent tool actions.

Commerce and workflow automation

Self-hosted n8n, Make and Zapier, event-driven retries, and two-way inventory, order and customer synchronization with WooCommerce and Shopify.

Enterprise integration

Secured C# / ODBC connectors to existing data systems, supported by web and mobile applications and reporting pipelines.

ARCHITECTURE & IMPLEMENTATION

The technology, and the work behind it.

How the documented stack supports the business workflow, from the application layer to integrations and operational controls.

Application and integration architecture

NestJS · Express.js · ASP.NET Core · REST · GraphQL · WebSockets

A microservices / hybrid-monolith architecture combines an API gateway with event-driven automation. NestJS handles core platform concerns such as tenants, permissions, subscriptions and billing; Express.js supports lightweight webhooks and ASP.NET Core handles heavier processing.

Data boundaries and enterprise connectivity

PostgreSQL / Supabase · SQL Server · Oracle · AS/400 DB2 · C# / ODBC

Tenant identifiers, PostgreSQL row-level security and FORCE RLS application roles define access boundaries. Composite indexes and partitioning support the data layer. Secured C# / ODBC connectors bridge existing enterprise systems; migrations use Prisma, TypeORM, EF Core and Flyway. The broader data stack includes MySQL, MongoDB and Redis.

AI service layer

FastAPI · LangChain / LangGraph · LlamaIndex · CrewAI · pgvector

Agents use function calling and per-tenant retrieval to work with the relevant knowledge. OpenAI and Anthropic integrations include automatic provider fallback, prompt-injection guardrails and idempotent tool actions. AI behavior is part of the application architecture, including the boundaries around what an agent may do.

Commerce and business automation

Self-hosted n8n · Make · Zapier · Redis · RabbitMQ

Event-driven workflows include retry handling and two-way synchronization of inventory, orders and customers. WooCommerce connects through PHP / Laravel plugins; Shopify integrations use GraphQL Admin and Storefront APIs and Liquid.

Customer applications and reporting

Next.js / React · TypeScript · Tailwind · shadcn/ui · Flutter · React Native

The delivery includes web and mobile surfaces, offline-first storage and push notifications. Python ETL connects reporting to Power BI and Tableau on read-only replicas, separating analysis from operational writes.

Controlled production delivery

Docker · GitHub Actions · GitLab CI · Sentry · Structured logging

Automatic staging and approved production releases support delivery. Redis idempotency keys, Redlock and circuit breakers address repeat actions and dependency failures. Observability includes structured logging through ELK, Datadog and Grafana Loki.

Follow the workflow

An illustrative walkthrough of the capabilities described in this project.

A customer-facing channel communicates through the platform APIs, where permissions and tenant boundaries govern access.
Business events can initiate automation, synchronize commerce records or call an AI service grounded in the tenant’s knowledge.
Connectors exchange data with existing enterprise systems, while retries, idempotency and logging make the integration behavior explicit.

The engineering behind the result

Tenant isolation was enforced with PostgreSQL row-level security. Idempotency keys, circuit breakers and structured logging addressed the failure modes of connected systems, while staging and approved releases controlled production changes.

What this enables

The result is a delivered platform where modern channels, AI workflows and existing enterprise data can operate together, with an architecture designed to accommodate further capabilities.

BUILD A SYSTEM AROUND YOUR BUSINESS

Your workflow could be the next case study.

If your roadmap spans SaaS, AI and integrations, you need someone who can design the whole system and implement the difficult connections. I bring architecture and hands-on engineering together, so the platform is shaped around your business rather than a collection of disconnected features.

Share your current systems, customer channels and the first capability you want to launch. We can define the architecture and a delivery milestone with clear acceptance criteria.

Work directly with Itzhak Shaul, founder of Methodspire and Principal Software Architect with 30+ years of hands-on experience. Start with a focused conversation about the workflow, constraints and delivery scope.

Selected freelance experience of Itzhak Shaul. Project details are summarized to protect client confidentiality.