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Custom SaaS Development
without the rewrite in month six.

I have seen what happens when architecture decisions get made in a 30-minute call before anyone has read the data model. Multi-tenant isolation breaks. The billing engine needs a rewrite before you hit 500 users. A race condition in the subscription flow quietly double-charges customers for three weeks before anyone catches it. I build SaaS platforms where those decisions are made correctly the first time, in writing, before a line of production code exists.

Build a Saas PlatformView Portfolio

Replies within 24 hours. No retainer required.

What I
actually build.

Every capability listed here is something I own end-to-end. I do not subcontract the backend and design the frontend. If it ships under my name, I built it. If it breaks in production, I fix it.

MVP to Production
5-10 wks
Post-Launch Rewrites
0
Start a Project

  • Multi-Tenant Architecture

    Schema-per-tenant and shared-schema models each carry real tradeoffs that depend on your data sensitivity, query volume, and cost structure. I design for tenant isolation that holds up under real load, not just in a test environment with three tenants.

    • PostgreSQL
    • Schema Isolation
    • Row-Level Security
    • Tenant Routing

  • Subscription Billing and Plan Management

    Stripe Billing implementation covering plan tiers, usage-based pricing, free trials, proration on upgrades and downgrades, and dunning logic for failed payments. The edge cases are handled explicitly: mid-cycle plan changes, payment method failures, credit application. Revenue does not leak quietly.

    • Stripe Billing
    • Plan Tiers
    • Trial Periods
    • Dunning Logic

  • Role-Based Access Control

    Granular RBAC across tenant, organization, and user levels. Permission matrices that scale with product complexity without requiring a schema migration every time you add a new role. Audit logs built in from the start.

    • RBAC
    • Permission Matrices
    • Org Hierarchy
    • Audit Logs

  • Onboarding and Activation Flows

    Structured onboarding that moves users from signup to their first value moment as fast as the product allows. Lifecycle automation, activation tracking, and in-app guidance. The architecture that serves users well on day one is different from the one that retains them on day sixty.

    • Lifecycle Automation
    • Activation Funnels
    • Progress Tracking
    • Email Sequences

  • Admin and User Dashboards

    Data-rich dashboards for both end-users and platform operators. Real-time metrics, tenant management, billing overviews, and activity feeds. Built with React Query or SWR so data stays fresh without hammering the database.

    • React Dashboards
    • Real-time Data
    • Tenant Management
    • Analytics

  • API Design and Third-Party Integrations

    REST and GraphQL APIs with versioning, rate limiting, and webhook infrastructure designed for third-party integrations and a future public API surface. The API contract is treated as a product artifact from day one, not something bolted on after the core build.

    • REST
    • GraphQL
    • Webhooks
    • Rate Limiting

Client Testimonial

SaaS Development

This was the first time I used Fiverr to build a dashboard and Assad Ullah exceeded my expectations. Not only did I get a robust site but the level of design went beyond cookie cutter to something that feels premium and customized!

Flex S.

Founder & CEO

Technical Ecosystem

Built with modern
scalable technologies

I use proven technologies like React, Next.js, Node.js, and AWS to build scalable SaaS platforms, high-performance APIs, and production-ready systems.

Core Stack

ReactNext.jsNode.jsLaravelAWSStripe

Frontend01

Next.jsReactTypeScriptTailwind CSSMaterial UIReact Query

Backend02

Node.jsExpressLaravelLumenREST APIsGraphQL

Database and Storage03

PostgreSQLMySQLMariaDBMongoDBAWS RDSRedisSupabaseFirebase

Billing and Infrastructure04

StripePayPalAWS (S3, SES, EC2)VercelDigitalOceanDockerCI/CD

How I run
a SaaS engagement.

Every phase in my process exists because I have seen what happens when it gets skipped. The architecture phase exists because scope discovered in week eight costs three times what it costs in week one. The milestone reviews exist because silent progress is how budgets disappear without a single difficult conversation.

  1. Product Decomposition and Risk Mapping

    Before any code exists, I map your product into its system components: tenant model, data schema, permission layers, and billing logic. The point is to find the architectural decisions that are expensive to reverse and make them correctly the first time. Scaling risks and technical constraints get documented here, not discovered in month four.

    Outcome

    A written system map covering tenant model, data ownership boundaries, permission layers, and billing logic. Each high-risk architectural decision is flagged and justified before the build begins.

  2. Architecture and Database Design

    Full system design: multi-tenant schema strategy covering schema-per-tenant versus row-level security, API contracts, RBAC structure, and third-party integration points. You get a production-grade blueprint with a clear rationale behind every decision. Not just a diagram that looks good in a slide deck.

    Outcome

    A production-grade architecture document: schema strategy, entity-relationship design, API surface definition, RBAC matrix, and third-party integration contracts. Every decision is documented with its tradeoffs, not just its conclusion.

  3. Schema Review and API Contract Sign-Off

    Before the first route gets written, the database schema and API contracts go through a dedicated review pass. This is the cheapest moment to catch a flawed foreign key relationship, a missing index, or an API shape that will make the frontend painful to build. Fixing these in a document costs an hour. Fixing them after the ORM models are wired costs a week.

    Outcome

    A signed-off schema and API contract that both sides have reviewed and agreed on. Frontend and backend development can start in parallel against a stable contract with no rework caused by late-stage shape changes.

  4. Core Platform Build

    Backend-first. Authentication, tenant isolation, billing integration, and the API layer get built and tested before the dashboard goes up. Frontend dashboards and onboarding flows are built on top of a stable, tested core. Not the other way around.

    Outcome

    A fully functional platform: working authentication, enforced tenant isolation, integrated Stripe billing, tested API layer, and operational dashboards. Every component is integration-tested before it is handed to the next layer.

  5. QA, Load Testing, and Launch

    Load testing, edge case coverage, and database query optimization before any production deployment. Infrastructure is provisioned with monitoring, alerting, and runbooks that someone other than me can follow at 2am.

    Outcome

    A production system with verified performance under load, documented edge case handling, a query-optimized database, active monitoring and alerting, and runbooks for the failure scenarios most likely to occur in the first 90 days.

View Full Methodology

SaaS Case Studies

Kodezi

AI-powered web IDE SaaS

View Case Study

Kodezi is not a thin wrapper around an LLM API. It's a full in-browser IDE — Monaco Editor with multi-tab state, diff views, codebase-aware context — with OpenAI integration that understands your actual project, not just the snippet you paste in. I built it from v1 through v4: the initial MVP, KodeziChat with real-time Socket.io streaming, a credits-gated subscription system enforced at the API level, a VS Code extension with native-feeling Webview UI, and separately, an automated system status tracker that replaced manual monitoring entirely. The 200K user milestone and Product Hunt Launch of the Month were outcomes of getting the product architecture right across four iterative versions.

  • 200K active users reached
  • Product Hunt Launch of the Month — February 2023
  • Monaco Editor web IDE with multi-tab and diff view
  • OpenAI API integration with full codebase context
  • KodeziChat: Socket.io real-time AI streaming
  • Stripe subscriptions with credits-gated feature access
  • VS Code extension UI via Webview API
  • Automated 90-day system status tracker

Proetutor

LMS platform development

View Case Study

Legacy Laravel and Bootstrap 3 systems age poorly. Slow Time to First Byte, failing Core Web Vitals, no protection on video URLs — Proetutor v1 had all of them. The rebuild wasn't just a UI refresh. It was a full architecture change: Next.js 15 with server-side rendering for SEO-indexed course pages, a clean Lumen v11 API layer, Bunny Stream replacing unprotected video hosting, and a monetization system that handles subscriptions and lifetime access from the same checkout. The result was a 97 performance score and a platform that ranks on the pages a legacy system never could.

  • 97 Lighthouse performance score
  • 92 Lighthouse SEO score
  • Legacy Laravel + Bootstrap 3 → Next.js 15 rebuild
  • Bunny Stream HLS video delivery with signed URLs
  • Subscription and lifetime access billing
  • SSR for SEO-indexed course pages

WATT Community Platform

private community platform development

View Case Study

Private community platforms fail in one of two ways: they either use off-the-shelf tools that don't integrate cleanly and feel cobbled together, or they get built as a real-time system that's underengineered and breaks under concurrent load. WATT Community needed to be a first-class product — not a Facebook Group with a custom header. Rich media posts with real-time updates across web and iOS simultaneously, group chat with full member management, a structured training system with protected Wistia video, and RBAC that means non-paying members genuinely can't access anything. All of it on a single Socket.io event layer shared between the Next.js web app and the React Native iOS app.

  • Real-time social feed — text, images, video — across web and iOS
  • 1:1 chat and member-managed group chats via Socket.io
  • React Native iOS app with feature parity to web
  • Admin-managed training playlists with Wistia video and downloadable resources
  • Role-based access control gating all platform features
  • FCM push notifications for feed activity, messages, and mentions
View Full Portfolio

This works if you already know
what bad architecture costs.

  • Founders Building a First Production SaaS

    You have a validated idea and need architecture that will not require a full rewrite at 500 users. I design the data model, tenant isolation strategy, and billing logic before writing a single route. Changing those things after launch is expensive. I have seen what that bill looks like.

    • Pre-launch or early-stage with a clear product scope
    • Need both architecture decisions and the actual build
    • Cannot afford to rebuild the foundation in six months

  • Teams Hitting a Scaling Wall

    Your SaaS is live and growing, but the architecture is starting to crack. Slow queries, tenant data bleed risks, billing edge cases that fire up support tickets. I have refactored enough of these systems to know where the bodies are buried.

    • Live product with performance bottlenecks or billing gaps
    • Adding multi-tenancy or subscription tiers to an existing system
    • Technical debt that is starting to block new feature work

  • Agencies Delivering a Complex SaaS Build

    You have won a SaaS contract and need a senior engineer to own the backend architecture, billing integration, and infrastructure decisions while you handle design and the client relationship. I have been that person on high-ticket builds before.

    • Agency or studio with a technically demanding client project
    • Backend complexity beyond what your current team covers
    • Need reliable, documented delivery with a clean handoff

Related Services

FAQ

Before you
reach out.

These are the questions I get on every first call. I would rather answer them here than spend the first 20 minutes of a discovery call covering ground we could have covered before it.

Yes. I own the full process: architecture, frontend, backend, database design, third-party integrations, and production deployment. You get one point of contact who understands the entire system, not three contractors who blame each other when something breaks at 2am.

Yes. Multi-tenancy is not a feature you bolt on later. The data isolation model, the row-level security strategy, and the indexing decisions all need to be correct from day one. I have rebuilt systems where this was an afterthought. It is expensive every time. Do it right the first time.

Before writing production code, I map the data model, define the API contract, identify every third-party integration point, and surface the decisions that are expensive to reverse. Shared vs. isolated database tenancy, synchronous vs. event-driven workflows, where the first performance bottleneck will appear under real load. This phase saves 2-4x its cost in avoided rework.

Yes. I start with an audit of your current codebase and infrastructure before recommending anything. Sometimes the right call is a targeted refactor. Sometimes it is a full rebuild with a careful data migration. I will tell you which one honestly, even if the rebuild is the less profitable answer for me.

With a change log and an honest conversation. Scope changes are not a crisis. Undocumented scope changes are. Every addition gets assessed for its impact on timeline and cost before it enters development. Nothing gets built in silence and invoiced as a surprise.

I write tests. Not as a checkbox, but because untested financial logic and untested auth flows are liabilities I do not want to hand off. I focus on integration tests for critical paths: payment flows, user provisioning, permission boundaries, and data isolation between tenants. Unit tests where the logic is complex enough to warrant them.

I set up CI/CD pipelines, environment separation between staging and production, and infrastructure on AWS or Vercel depending on what the project actually needs. I do not push to main and refresh the browser. Deployments are automated, rollbacks are possible, and production is never the first place a change gets tested.

I offer post-launch support and retainer arrangements for teams that need ongoing development. I am also direct about what you need internally as you scale. If you are at the point where you need a full-time engineer, I will tell you that rather than keep billing you for work that should be in-house.

Start a SaaS Project

Ready to build
your SaaS platform?

You get a documented architecture, a scoped timeline, and a straight answer on cost before any code is written. Send me your brief and I will tell you exactly what it takes to get to production.

What to Expect

  • Response within 24 hours
  • Free architecture scoping call
  • Clear proposal with timeline & cost
  • No obligation to proceed
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Typically responds within 24 hours