Damon Zhang

A legacy Laravel tax platform rebuilt as a Next.js and TypeScript monorepo, running as 7 Docker services behind Caddy and Cloudflare.

• Tax engine built from 186 golden assertions written before implementation, now 1,100+ automated tests.
• 1,070 results reconciled against the legacy system: 999 exact matches, 71 documented differences, 0 unexplained.
• Multi-tenant data secured with PostgreSQL row-level security, decimal maths and idempotent writes.
• 8-language UI, invoicing, outbox email and an AI-assisted document inbox.

• Next.js 15
• TypeScript
• PostgreSQL 16
• Drizzle
• oRPC
• pg-boss
• Docker

About 90 static websites moved off a shared legacy server onto CloudFront with private S3 origins, each provisioned as its own CloudFormation stack with a tested rollback path.

• ACM certificates, DNS cutover and a documented rollback for every site.
• Edge caching fixed for 131 CloudFront hosts across 21 Cloudflare zones: they were 94% of request volume, now 16% of their old requests, verified with 131/131 cache hits.
• Least-privilege IAM permission set validated with policy simulation, so a second operator can publish independently.

• CloudFront
• S3 + OAC
• CloudFormation
• ACM
• IAM
• Cloudflare

A client's legacy Java ad-operations back office, rebuilt as a multi-tenant Next.js SaaS for publishers, domains, ad units, ad scripts, ads.txt and revenue-share reporting.

• Google Ad Manager and GA4 data arrive through lease-guarded, idempotent background syncs; no page waits on Google. The first real sync on staging pulled 778 ad units across 3 networks, then 1,842 report rows in 22 seconds.
• Revenue share stored as append-only integer micros, checked against the vendor dashboard.
• 7-role server-side RBAC, audit logs and an 8-language UI.
• Exact-SHA releases gated by a 474-test Playwright preflight with rollback; the full suite passed 459/459 twice in a row.

• Next.js 16
• Prisma
• PostgreSQL 18
• Google Ad Manager API
• GA4 Data API
• Playwright

After a client's dedicated server failed and was reinstalled, AI-agent automation I directed brought its static sites back overnight.

• Scanned 307 hosts for DNS, Cloudflare SSL mode, HTTP status and TLS, and sorted them into restore, skip and exclude.
• Redeployed 292 sites through preflight, backup, apply, validate and automatic rollback; the rollback fired once and the rerun passed.
• All 301 in-scope sites back on HTTPS with valid certificates, with a per-site report for the client.

• Linux
• Nginx
• Let's Encrypt
• Cloudflare
• AI coding agents

Public, member and staff workflows for households, events, attendance, venue hire, giving and reporting, in 7 languages.

• Server-side role, record and field-level access control with append-only audit logs.
• Deposits, refunds and recurring giving built on integer-cent maths, transactions, locks and idempotency keys.
• Authorisation verified by REST and GraphQL tests in CI.

• Next.js 16
• Payload CMS 3
• PostgreSQL
• Vitest
• Playwright
• GitHub Actions

A venue management system that replaced legacy software across multiple venues: court scheduling, customer portal, e-commerce, invoicing and financial tracking.

• Customer-facing booking portal and staff back office in one system.
• CI/CD pipelines and Jest-based testing introduced so the team could keep shipping safely.

• Next.js
• Laravel
• Jest
• CI/CD

Search Auckland resource consent applications by address, backed by an hourly sync of the council's published applications list.

• Hourly, idempotent sync of the council PDF; the first hourly run added 247 records and updated 3 with 0 failures.
• Live LINZ address lookup and PostGIS radius search, with weekly capped geocoding for records without coordinates.

• Next.js
• Supabase
• PostGIS
• pdf.js

Local browser tools for image conversion, OCR and PDF work, plus 8 Markdown converters for PDF, DOCX, PPTX, XLSX, HTML, CSV, JSON and EPUB.

• Static front ends on Cloudflare Pages with a containerised conversion backend, deployed through GitHub Actions.

• Vite
• Cloudflare Pages
• Docker
• GitHub Actions