MK/CASTRO

Shipped, deployed, survived

The work

Every project here ran in production: business platforms, SaaS rebuilds, fintech systems, partner portals, legacy revivals. Studio work sits alongside the systems our founder built and led before the studio, because that is the standard your project gets.

/01

Full stack

Next.js, React, Laravel, PostgreSQL, auth, payments, dashboards, deploys.

/02

Modernization

Legacy systems rebuilt into modern product surfaces without losing business logic.

/03

Production ownership

Event tracking, partner portals, background jobs, CI/CD — not just landing pages.

/04

Senior by default

Ambiguous requirements in, shipped product out. Observable, testable, deployable.

/01

Proof first

The work we would want reviewed first: architecture, product surface, integrations, data flow, production ownership.

Studio project · Production SaaS

Event Designs by Tiffany

Built tiffanydecastro.com from zero into a production platform that runs an event design business in Baguio end-to-end. Clients browse the catalog, build estimates, and book events through a guided flow; the back office manages inquiries, bookings, payments, contracts, calendar, and full accounting (events, expenses, suppliers, workers, rentals, and reports). Delivered with Next.js 16 App Router, React 19, TypeScript, Prisma 7 on PostgreSQL, Clerk authentication, Vercel Blob, and Resend + React Email, backed by Vitest unit tests and Playwright E2E and visual regression suites.

  • Next.js
  • React
  • TypeScript
  • Prisma
  • PostgreSQL
  • Tailwind CSS
  • shadcn/ui
  • Clerk
Case studyLive site

Studio project · Client production site

One Twenty-Three

Designed and built one-23-events.com for One Twenty-Three Weddings & Events: an editorial landing page, a filterable portfolio of 170+ event photos, an about page, a press wall, and a free discovery-call booking flow. Availability is computed from recurring weekly rules minus blackouts minus bookings, never pre-generated, with a 12-hour lead time and a 30-day horizon; a partial unique index in PostgreSQL makes double-booking impossible. Clients sign in with Google through Clerk so every confirmation reaches a verified inbox, then receive Resend emails with .ics attachments in Manila time, and the planner pastes the meeting link from a private admin queue to confirm each call. Built with Next.js 16, React 19, TypeScript, and Tailwind CSS v4 on Neon PostgreSQL and Vercel.

  • Next.js
  • React
  • TypeScript
  • PostgreSQL
  • Tailwind CSS
  • Clerk
  • Resend
  • Vercel
Case studyLive site

Production SaaS

BankRolls Tools Event-Tracker

Designed and built track.bankrolls.tools from scratch as a high-performance affiliate tracking system combining click redirects with webhook/postback processing. Implemented registration, deposit, withdrawal, CPA, and CPL event flows with PostgreSQL, Redis/ElastiCache, AWS SQS/SNS, worker consumers, health checks, tests, Dockerized environments, GitHub Actions, and production deployment workflows. Developed APIs capable of handling 300 concurrent requests per second with sub-200ms average response times.

  • TypeScript
  • Next.js
  • Drizzle ORM
  • PostgreSQL
  • Redis
  • ElastiCache
  • SQS
  • SNS
Case studyLive site

Production SaaS rebuild

CryptoBack Club

Led the rapid rebuild of CryptoBack from the Laravel/Livewire implementation into a modern Next.js 16 and React 19 application. Recreated the core product experience across marketing, authentication, offer wall, dashboard, leaderboard, referrals, payment/withdrawal flows, i18n, attribution, and deployment workflows using Drizzle ORM, PostgreSQL, Clerk, Vercel, and automated tests.

  • TypeScript
  • Next.js
  • React
  • Drizzle ORM
  • PostgreSQL
  • Clerk
  • Vercel
  • GitHub Actions
Case studyLive site
/02

In pictures

Every project with screenshots. Filter by stack, search by name, or flip to the table.

Resend

Showing 4 of 17 projects

Event Designs by Tiffany

Studio project · CTO & Co-founder · Founder-led · Production SaaS

Event Designs by Tiffany

Complete business platform for an event design company — marketing site, client estimator and booking flow, and admin back office

  • Next.js
  • React
  • TypeScript
  • Prisma
  • +6
One Twenty-Three

Studio project · Designer & Developer · Solo · Client production site

One Twenty-Three

Editorial marketing site and discovery-call booking system for a Baguio wedding and events planner

  • Next.js
  • React
  • TypeScript
  • PostgreSQL
  • +5
ChessPrep Club

Solo Developer · Solo · Startup MVP

ChessPrep Club

Chess Opening Trainer with Spaced Repetition

  • TypeScript
  • Next.js
  • React
  • Clerk
  • +5
Rummy Treasure

Lead Developer · 2-3 developers · Startup MVP

Rummy Treasure

Indian Rummy for Indian market

  • TypeScript
  • Next.js
  • React
  • Clerk
  • +5
/03

No screenshots, still shipped

Internal systems, backends, and platforms that lived behind logins or VPNs — the work was real even where the pixels are private.

CrewCalls

Full Stack → Senior → Lead · Production SaaS

Actor management (nudity openness, age, typical actor info)

/PHP /Laravel /Vue.js /MySQL /Pusher /Laravel Echo

xswap

Lead → Interim CTO · Fintech/Regulated

Payroll disbursement platform for SMEs (batch salary payments via GCash-like service)

/TypeScript /PHP /Laravel /React /MySQL /EC2

TheWorkPlace

Co-founder · Pre-launch venture

Virtual office and business center platform — client portal for signup, service selection, onboarding, and order tracking (in development)

/Next.js /React /TypeScript /Drizzle ORM /PostgreSQL /Tailwind CSS

BankRolls Tools

Senior Developer · Production SaaS

Legacy client platform

/PHP /Laravel /PostgreSQL /EC2

Xawna Platform

Lead → Head of IT · Startup

Main platform

/TypeScript /PHP /Laravel /React /MySQL /Vercel

Xawna Mobile

Lead → Head of IT · Startup

React Native prototype

/TypeScript /React Native

CCA Heartbeat

Full Stack → Senior → Lead · Internal Tool

Internal uptime monitoring (mostly led/merged PRs, foundation code)

/PHP /Laravel /Code Review /Bootstrap /jQuery

CallSheets

Full Stack → Senior → Lead · Production SaaS

Crew scheduling automation (grip, camera, scene scheduling) - has real-time messaging

/PHP /Laravel /Vue.js /MySQL /Pusher /Laravel Echo

Milkyway E-commerce

Full Stack Developer · Enterprise E-commerce

E-commerce platform (bags, watches, typical Chinese goods)

/PHP /Laravel /MySQL /OAuth2 /Shopify /Bootstrap

NDBD E-commerce Stores

Full Stack Developer · Enterprise E-commerce

74 stores selling refurbished phones

/Shopify /Shell