Full-stack engineer & founder

I build software
from idea to production.

I’m Joel, a Dallas-based full-stack engineer with six-plus years of experience. I take web and mobile products from idea to production, owning product design, frontend and backend development, testing, deployment, and ongoing maintenance.

Core toolkit

TypeScript
React
Next.js
Node.js
Express
React Native
Expo
PostgreSQL
Convex
MCP
Claude Code
Codex
Cursor

View selected work Download resume

Dallas, Texas · Open to senior full-stack roles

01 / Selected work

Products I build and run.

Booking, notes, and reminders. I design the interfaces, build the systems behind them, and maintain the products.

Featured / Booking & scheduling

Separalo

Online booking for
independent service businesses.

I designed and built the multi-tenant product: public booking pages, staff availability, calendars, bilingual support, and Stripe subscriptions.

My role Product design, frontend, backend, and ongoing operations.

Next.jsTypeScriptConvexStripe

Visit Separalo

Separalo website presenting its booking calendar and business dashboard

Public booking pages and a shared business calendar.

Explore Separalo’s technical details

From request to reservation

Customers choose a service and an available time through a public booking link. Businesses manage reservations, staff schedules, and availability in a shared calendar.

Separate business workspaces

A reactive Convex backend supports tenant isolation, team access controls, and automatic staff assignment. The interface supports English and Spanish.

Billing and maintenance

I maintain the product end to end, including Stripe subscriptions, booking flows, and the everyday tools businesses use to manage their schedules.

Notes & collaboration

Compendai

A workspace for notes, nested folders, and reusable snippets. I built the rich-text editor and optional cloud sync, with recent work on collaborative editing, revision recovery, and authenticated MCP access.

My role Product design and full-stack development.

ReactTiptapConvexMCP

Visit Compendai

Mobile & recurring reminders

Nottifai

A mobile app for one-time plans and recurring events. I built the Expo app and Convex backend, including multiple alerts, timezone-aware scheduling, and scheduled email reminders.

My role Product design, mobile app, and backend.

ExpoReact NativeConvexResend

Visit Nottifai

02 / Experience

Engineering experience.

Six-plus years across enterprise software and independent products.

Nov 2025 – present

Founder & Software Engineer

Nottifai LLC

Founded Nottifai LLC to build and operate independent software. Lead product design and full-stack development across booking, note-taking, and reminder tools, including billing and ongoing maintenance.

Ended May 2026

Senior Software Engineer

Clear C2 · Dallas, TX

Built and maintained enterprise CRM features across the frontend and backend, connecting React and TypeScript interfaces with PHP application logic.

2019 to 2025

Full-stack Engineer

Prior roles and contracts

Delivered production features across React, TypeScript, Node.js, and PHP, with PostgreSQL and Convex data layers, Stripe billing, and supporting infrastructure.

03 / About

How I build.

I take products from the initial idea through launch and ongoing maintenance. That means shaping the scope, designing the interface, modeling the data, and building the frontend and backend.

The work continues after launch: keeping deployments reliable, maintaining billing and access controls, and improving the product as people use it.

Supporting technologies

Tailwind CSS
shadcn/ui
Stripe
Vercel
Cloudflare
Git
PHP
Astro
Railway
Sentry
Umami
Google Cloud Console

I use these alongside my core stack for styling, payments, deployment, monitoring, analytics, and cloud infrastructure.

Have something in mind?

Let’s build something useful.

I’m open to senior full-stack roles, product engineering work, and conversations with people building ambitious software.

Email me

LinkedIn ↗Download resume ↓

joelecastilloj@gmail.com