Senior engineering — minus the agency overhead.
Ninja Web Design is the studio of Daniel Serrano, a senior web developer based in Newark, NJ. For over a decade I've helped businesses ship websites, apps, and AI-powered tools that earn their keep — measurable rankings, real conversions, and code that doesn't fall apart at version two.
The short version.
I started building websites in 2018 and have been hands-on full time ever since. Today I build and optimize websites for Century Mechanical Holdings' home-service brands while running my own practice for direct clients. That mix keeps me sharp on both the marketing side (rankings, conversions, attribution) and the deep engineering side (architecture, performance, security).
I work best with founders, marketers, and operators who want a senior engineer they can actually talk to. No layers, no handoffs, no surprise scope.
Education
Where I'm based
What I've shipped.
Web Developer
Century Mechanical Holdings
- Build mobile-first CMH home-service sites focused on lead generation and UX
- Optimize conversions across phone calls, bookings, and qualified lead flow
- Manage ServiceTitan, GA4, GTM, Search Console, and call-tracking integrations
- Improve site speed, technical SEO, accessibility, and local search visibility
- Support launches, acquisitions, hosting, domains, and cross-team analytics
Senior Web Developer
XDC Marketing & Branding
- Boosted SEO from 20+ position to first-page rankings in under 30 days
- Increased sales by 200%+ and GA4 conversion events by 200%+
- Managed 250+ sites and applications (currently 76+ active)
Senior WordPress Developer
Solebury Strategic Communications
- Built and maintained WordPress sites for public-affairs and political clients
- Custom theme and plugin development with performance optimization
Frontend Developer
Vallen Distribution
- Built backend admin components for managing eCommerce users and permissions
- Created product detail page component and product archive with Algolia-powered filter, search, and sort
- Developed a unified UI wireframe used across all admin components
Self-Employed Software Engineer
Ninja Web Design
- Direct client engagements across web, mobile, and AI projects
- Full-stack delivery from discovery through deployment and maintenance
What's in the toolbox.
I pick tools based on what fits the problem — not the other way around.
Code
- AI
- TypeScript
- JavaScript
- PHP
- Python
- Node.js
- SQL
- NoSQL
Frontend
- Angular
- React
- Vue
- jQuery
- Bootstrap
- SASS
- LESS
CMS
- WordPress
- Shopify
- Wix
- Duda
- Squarespace
Mobile
- Ionic Framework
- React Native
- Capacitor
Tools
- Google Search Console
- GA4
- WHM Server
- cPanel
- Plex