Status: Availability: Available for new projects

Senior Frontend Developer Modernizing Legacy Frontends

I help enterprise teams and ambitious startups turn slow, tangled Angular frontends into clean, modular systems that ship faster and stay fast. Expect measurable performance wins, audit-ready engineering practices, and architecture that scales with your product.

Book Discovery CallModernize or Build SaaS
Shop TemplatesOne-time purchase
View Portfolio Validate quality first

Core Technology Stack

  • Angular
  • TypeScript
  • Tailwind
Interactive code comparison showing migration from legacy to modern Angular 
import { Component, signal } from '@angular/core';

@Component({
  standalone: true,
  changeDetection: ChangeDetectionStrategy.OnPush,
  template: `
    <h1>{{ title() }}</h1>
    <button (click)="update()">Update</button>
  `
})
export class ModernComponent {
  title = signal('Fast & Reactive 🚀');

  update() {
    this.title.set('Modernized!');
  }
}

The Challenge

Your Frontend Is Holding Your Product Back.

  • Legacy Teams

    Slow, tangled Angular frontends blocking feature velocity. Your roadmap says "innovate"—your codebase says "three-week review cycles."

  • SaaS Founders

    You need a technical co-founder's output without giving up equity. Design files exist. User research is done. But engineering execution? Still searching.

  • Growth Teams

    Marketing needs landing pages yesterday. Your dev team's sprint is booked for six weeks. Templates you've tried fall apart the moment you add real content.

Whether you need architecture-level intervention, end-to-end SaaS delivery, or production-ready templates you can customize in minutes, you're choosing from the same engineering standards— just different delivery formats. —

Services & Value Proposition

Bank-Grade Engineering. Startup-Speed Delivery.

For enterprise teams and ambitious startups, I modernize legacy frontends, fix performance bottlenecks, and build modular Angular systems that stay maintainable as your product grows. Clear outcomes, measurable wins, and audit-ready quality.

Enterprise Modernization

Transform slow, tangled legacy frontends into clean, modular Angular systems.

  • Angular migrations (Legacy → Modern)
  • Architecture Audits & Performance
  • Fractional Tech Lead / Mentorship
  • Refactoring & Technical Debt Removal
Book Discovery Call

SaaS Product Engineering

Most Popular

End-to-end delivery for scalable SaaS products.

  • End-to-end Feature Delivery
  • Predictable State Management
  • Performance-First Architecture
  • Rapid Iteration Support
Book Discovery Call

Scale Sail Templates

Ship a high-converting landing page today. Built with the same standards.

  • Production-ready HTML/CSS/JS
  • Commercial use included
  • No framework required
  • Deploy in minutes
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Ready Templates

Ship a Landing Page Today.

Production-ready templates built with the same frontend standards as my enterprise work. Pick one, customize in minutes, deploy anywhere.

  • Free Download
    Mintly

    Mintly

    Trust-first layout for modern finance products

    Free Forever
  • CleanFleet Solutions

    CleanFleet Solutions

    Includes ROI calculator for fleet decision-makers

    One-time purchase
  • InnovateTech

    InnovateTech

    Premium motion + strong CTA placement

    One-time purchase
Shop All Templates

The Process

From Discovery to Deployment

  1. Step 01: Discovery & Audit

    Review architecture and set clear scope.

  2. Step 02: Execution

    Structured sprints, regular updates, no surprises.

  3. Step 03: Handoff & Support

    Full docs, deployment guides, team training.

The Founder

Engineering for Scale & Performance

Karol Modelski Senior Frontend Developer & Founder
Senior Frontend Dev (6+ yrs) Micro-SaaS Founder Angular Expert

Delivering modernization and performance improvements at scale—from regulated enterprise platforms to high-velocity product teams.

Currently leading architecture for mission-critical trading platforms: Enforcing 100% test coverage policies while migrating legacy micro-frontends to a coherent Nx monorepo. Balancing enterprise compliance with developer velocity.

At Silent Eight (AI Compliance SaaS), I led the frontend modernization initiative (Angular 14 → 19) and introduced 'Zoneless' architecture for 50% performance gains. Worked directly with Product Owners to accelerate feature delivery.

At GOonline Platform, I delivered features for 1M+ active users. Managed the complex migration of core banking modules from AngularJS, ensuring zero downtime during high-traffic windows.

For Amway Global E-commerce, I built high-traffic dashboards for business owners. Optimized data visualization components handling millions of records.

Philosophy: Software is built by people. I foster environments where technical excellence meets product vision.

Portrait of Karol Modelski, Founder

Core Advantage

Business-First Engineering

Compare Options

Choose Your Engagement Model

  • Most Popular

    Legacy Modernization

    Eliminating technical debt & scaling bottlenecks

    • Timeline: 4-12 Weeks
    • Investment: Custom Quote
    Book Discovery Call

  • Feature Delivery

    Accelerating roadmaps & complex integrations

    • Timeline: 2-6 Weeks
    • Investment: Custom Quote
    Book Discovery Call

  • SaaS Engineering

    Building scalable, audit-ready SaaS

    • Timeline: 3-6 Months
    • Investment: Custom Quote
    Book Discovery Call

  • Audits & Performance

    Identifying bottlenecks & Core Web Vitals

    • Timeline: 1-2 Weeks
    • Investment: Fixed Price
    Book Audit

  • Tech Lead / Mentor

    Elevating team capabilities & best practices

    • Timeline: Ongoing
    • Investment: Retainer
    Discuss Role

  • Ready-to-Ship Templates

    Validating ideas with production-grade code

    • Timeline: Immediate
    • Investment: Free - $9.99
    Shop Templates

FAQ

Common Questions Before You Start.

Have a different question? Contact support and I’ll get back to you.

Do you work with both enterprise and startups?
Yes. Enterprise clients hire me for modernization, audits, and fractional tech leadership. Startups hire me to build their SaaS product end-to-end or as a technical advisor. Both get the same quality bar—audit-ready code and measurable performance wins.
What's included in a discovery call?
I'll review your current state (codebase, product requirements, or goals), identify key bottlenecks or risks, and propose a clear scope with timeline and outcomes. No sales pitch—just engineering clarity.
Can I start with templates and upgrade to custom work later?
Absolutely. Many clients validate their idea with a Scale Sail template, then hire me to build the full SaaS product once they have traction.
What frameworks do you specialize in?
Angular is my specialty (AngularJS → modern migrations, Signals, RxJS, Nx monorepos). I also ship React when your stack or roadmap requires it.
Do templates work for non-developers?
Yes. Templates are static HTML/CSS/JS with a customization guide. If you can edit text and change colors in a file, you can deploy them. Support form included for issues.
What's your availability?
Currently booking Q1 2026 projects. Template purchases are instant (download after payment).

Ship with Confidence.

If you're dealing with a slow, hard-to-change frontend (or planning a new SaaS build), I can help you ship with confidence. Share your goals and constraints—I'll review your inquiry and if it's a good fit, I'll send you a link to book a discovery call.