Available for new projects

Hi, I'mKent O'SullivanI design and build custom web systems for businesses with real problems to solve

Multi-tenant storefronts, subscription and payment systems, booking platforms, custom internal tools—if you can describe the problem, I can architect and build the system that solves it. The kind of work where the logic matters, not just the pixels.

About Me

Custom platforms and systems, built around what your business actually needs

Hi! I'm Kent—a software engineer and systems architect based in Pleasant Grove, Utah. For over five years I've designed and built custom web platforms: international storefronts, content and admin systems, and the kind of production software that has to stay correct when real money and real users hit it.

I work best where the logic matters. Multi-language commerce across six countries, geospatial search that stays fast at scale, subscription billing, custom admin tools—the complexity is the point, not something to hide from. My work so far has spanned wellness brands and international commerce, but I'm not tied to any one industry; the common thread is the complexity, not the vertical.

You work directly with me, start to finish—no handoffs, no account managers. I care as much about the unglamorous edge cases as the polished surface, because that's exactly where cheaper builds break. Bring me a problem and I'll figure out how to build it—that's the part I enjoy most.

  • 6 Countries Served
  • 21 Languages Shipped
  • 5+ Years Building
  • Full-stack Front-end to database

Systems, Not Just Sites

I build the logic behind the interface, not just the pixels. Past work includes payments, subscriptions, multi-tenancy, integrations, and custom admin tools—and I take on new problems as they come.

Global by Default

I've shipped multi-language, multi-currency platforms across six countries and 21 languages—localized all the way down to the checkout.

Built to Hold Up

Correctness, security, and performance engineered in—load-tested and monitored, not hoped for. The unglamorous edge cases are exactly where cheaper builds break.

Selected Work

Production platforms and systems I've designed and built—each one a different problem, solved from the ground up.

Full-Stack Provider Directory PlatformLive

HWI Care

A shipped, full-stack platform for a national health-and-wellness licensing company: a fast geospatial provider directory, a custom page-builder CMS, and a role-based staff admin — proven at 100,000 records with sub-200ms search.

  • Directory search under 200ms, load-tested past 100,000 records
  • Custom page-builder CMS with draft previews, publish, and version-history rollback
  • Role-based staff admin with every change logged for accountability
View case study
Systems Architecture · Designed, Not ShippedArchitecture

Multi-Tenant Commerce Platform

The complete end-to-end architecture, specification, and 14-phase build plan for a custom multi-tenant storefront platform — branded partner storefronts, in-house subscriptions, a commission ledger, payouts, and tax. Designed end-to-end; leadership licensed a vendor before build began. A study in how I architect a system from scratch.

  • Integer-cent commission ledger — money tracked to the exact penny, snapshotted at order time
  • Custom subscription scheduler over card-vault tokenization (arbitrary cadences, smart dunning)
  • PCI SAQ A: card data never touches the server
View case study
International Commerce PlatformLive

Prife Shop

A custom international storefront for a global wellness brand — shoppers browse, subscribe, and check out in their own language and currency across six countries and 21 languages.

  • Shopping, subscriptions, and checkout localized across 21 languages and six markets
  • Multi-step, region-aware checkout — country-specific shipping, state/province tax, payments
  • Custom commerce logic: points-based tier progression, subscription discounting, partner enrollment
View case study
Wellness Booking PlatformLive

Thera Gallery

A multi-language wellness platform: clients find their nearest partner center on an interactive map and book an appointment — with partner pages assembled through a custom drag-and-drop site builder, in seven languages.

  • Custom drag-and-drop site builder — 20+ configurable sections, nine design themes
  • Integrated Cal.com appointment booking on partner location pages
  • Interactive map to find the nearest partner center
View case study
School Platform · Custom E-Commerce & Headless CMSLive

Liahona Preparatory Academy

A fully custom platform for a private school: a headless CMS the staff run themselves — pages and navigation alike — an interactive events calendar, and complete e-commerce built from scratch.

  • Complete custom e-commerce — catalog with inventory, persistent cart, checkout, order processing
  • Checkout integrated with the client’s preferred payment gateway
  • Staff edit every page — and the site navigation itself — through a headless CMS
View case study

What I've Built

A sample of the systems I've designed and built—not a fixed menu. Don't see your project here? It's likely still something I can do.

Systems & Platform Architecture

The hard stuff: multi-tenant platforms, subscription and payment systems, marketplace and commission logic, backend and API design. I design the whole system before the build, so it stays correct and doesn’t fall over the first time real load hits it.

  • Multi-tenant architecture
  • Subscriptions, billing & payouts
  • Backend & API design

International Commerce

Storefronts that sell across borders: multi-language, multi-currency, multi-market—localized down to the checkout, not just the marketing copy. Proven across six countries and 21 languages.

  • Multi-currency, multi-language checkout
  • Subscriptions & saved carts
  • Native-feeling in every market

Platform Migration

When your current setup is fighting you—page-builder limits, plugin sprawl, or a platform that can’t do what you now need. I move you onto a custom system built around how your business actually works, without the customization walls and the scaling costs.

  • Escape platform & plugin ceilings
  • Keep the workflows that work
  • Own your platform outright

Integrations & Custom Tools

Booking and scheduling, geospatial search, custom CMS and page builders, CRM and payment integrations—and the internal admin tools your team actually runs on day to day.

  • Booking & scheduling systems
  • Custom CMS & admin dashboards
  • Third-party & payment integrations

Why Work With Me

Design Before Build

Data models, flows, and edge cases documented first—no mid-project surprises, no surprise invoices.

Security & Correctness First

Built in from the start, not bolted on. Past work includes exact, audited financial math, hardened logins, and integrations verified before they’re trusted.

I Ship & Maintain

No deliver-and-vanish. Monitoring, error tracking, and updates keep it running long after launch.

How I Work

A clear path from first conversation to a system that’s live—and looked after.

  1. Design

    We map out exactly what you need first—data models, user flows, and the edge cases—so the build is predictable and there are no surprises later.

  2. Develop

    I build in focused iterations, showing you real, working software as it comes together—not a black box you wait months to see.

  3. Launch

    Testing, hardening, and a clean deploy. Launch day is a non-event, because everything has already been verified.

  4. Support

    I don’t disappear at launch. I keep it running, monitored, and evolving as your business grows.

Is this right for you?

Custom isn’t always the answer—and I’ll tell you when it isn’t. Here’s an honest read on whether we’re a fit.

Probably not a fit

If this sounds like you, a page builder like Shopify or Squarespace is likely the right tool—faster and cheaper than a custom build. I’ll happily point you in the right direction.

  • A simple 5-page brochure site
  • A basic store with a standard checkout
  • A template you plan to manage yourself
  • The lowest possible price is the priority

Where I come in

When a platform can’t handle what you actually need, a custom system pays for itself. That’s the work I do.

  • Off-the-shelf tools can’t do what you actually need
  • You’ve hit the limits of your current platform
  • Your business logic is complex or genuinely unique
  • You need real integrations or custom internal tools
  • It has to stay fast, secure, and correct as it grows
Sounds like you? Let’s talk

An Ongoing Partnership

Launch isn’t the finish line. After it ships, I stick around to keep your platform healthy and moving forward.

Clients can keep me on a monthly retainer: a concrete block of included hours for priority access, maintenance, security updates, and new-feature development—with anything beyond it billed hourly. It’s a real resource with reserved time, not a vague promise to be “on call.”

Priority access

A direct line to me and a predictable block of hours reserved each month.

Maintenance & security

Dependency and security updates, monitoring, and fixes before they become fires.

New features

Iterate as your business grows—new flows, integrations, and capabilities over time.

Let's Work Together

Have a project in mind? I'd love to hear about it.

Location

Pleasant Grove, Utah

Availability

Open for freelance work

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