Senior web developer / product engineering

I build software systems
that stay understandable.

Web applications, native tools, and the infrastructure between them. I care about clear interfaces, explicit data ownership, and software that behaves well in production.

Selected systemsGitHub

Selected systems

Architecture over screenshots. The interesting part is how the pieces fit together.

Private system / 2026

HELIOS

A private multi-domain operating system built around canonical data, derived intelligence, and focused action surfaces.

HELIOS

Highly Efficient, Loyal, Intelligent Operating System

The platform: one private system for data, health, training, planning, research, and everyday operations.

OTIS

Observant, Thoughtful, Intelligent Servant

The intelligence inside HELIOS: the conversational layer that interprets data, builds briefings, catches missed items, and suggests next actions.

HELIOS is the manor. OTIS is the butler.

  • Next.js
  • TypeScript
  • Supabase
  • PostgreSQL
  • PostHog
  • Sentry

Architecture only. No production data or personal screens are shown.

Native capture
Canonical data
HELIOS
OTIS

Canonical data

Authoritative sources stay authoritative instead of being copied into competing versions of truth.

Explainable intelligence

Derived state is designed around provenance, freshness, confidence, and visible uncertainty.

Clear boundaries

Web, native, automation, and data layers share contracts without duplicating business logic.

Native iOS companion / 2026

Origin

An iPhone companion for fast capture, sync, and daily actions, designed around server-owned contracts and offline-safe writes.

  • Swift 6
  • SwiftUI
  • HealthKit
  • GRDB
  • Supabase
  • Widgets

Pre-release system. Architecture is shown without live user data.

HealthKit
Offline queue
Versioned RPCs
Server-owned state

Server authority

The client presents and captures data without inventing a second source of truth.

Offline durability

Writes survive poor connectivity through a durable local operation queue and bounded caches.

Privacy by design

Sensitive values stay out of analytics, diagnostics, notifications, and public-facing material.

Public work

Selected shipped work. Smaller products where the interface can speak for itself.

Foodie Buddy project preview

iOS app / 2025

Foodie Buddy

An iOS app that turns natural-language food descriptions into structured meal logging with macro and micronutrient tracking.

Product, design, developmentfoodiebuddy.app
Sthephany & Seth project preview

Web platform / 2026

Sthephany & Seth

A bilingual destination-wedding platform with a custom household RSVP system, private planning tools, and guest analytics.

Custom RSVP system

Personal household links

Each household gets a memorable invite code and personal link that opens directly into its own guest list.

Guest-aware responses

Attendance is captured per invited guest, with plus-ones only where allowed and their event access inherited automatically.

English and Spanish

The RSVP experience, validation, and confirmation emails stay in the guest’s selected language.

Useful guest details

Dietary needs, questions, song requests, contact details, and other notes are captured alongside attendance.

Safe repeat submissions

Idempotent writes, server-side invitation validation, deadline controls, and spam protection keep duplicate or invalid replies out.

Private RSVP analytics

The couple can see response rate, projected headcount, per-event totals, changed replies, form drop-off, and who opened but has not replied.

Design, development, ongoing caresthephandseth.com
Countdowns project preview

Web app / 2024

Countdowns

A focused web app for keeping meaningful dates visible without turning them into another productivity system.

Design & developmenttocklet.app
Format Goodly project preview

Web utility / 2025

Format Goodly

A small web utility that cleans messy clipboard text in one step: spacing, quotes, line breaks, and inconsistent formatting.

Design & developmentformatgoodly.app
Dell Spanish Solutions project preview

Client website / 2024

Dell Spanish Solutions

A fast, straightforward marketing site for a local language-services business.

Design & developmentdellspanishsolutions.com

Approach

How I work. Clear decisions, solid execution.

01

Product thinking

Start with the behavior and workflow. Framework choices come after the problem is understood.

02

Systems architecture

Make ownership, boundaries, failure modes, migrations, and sources of truth explicit.

03

Interface design

Complex systems should still feel quiet, legible, and obvious to operate.

04

Production engineering

Performance, accessibility, observability, and maintainability are part of the product.

Production engineering

Built to hold up in production.

Most of my day-to-day work is production software: migrations, integrations, performance, observability, maintenance, and the details that keep systems dependable.

  • React and Next.js application architecture
  • Design-system and dependency migrations
  • Authentication and platform integrations
  • Performance and Core Web Vitals
  • Analytics, observability, and production debugging
  • APIs, automation, and data-backed product work

Contact

Want to talk software?

Email is best. I’ll get back to you.

hello@o-s-c-a-r.com