Senior Full-Stack Engineer (Freelance)

Marc Itzenthaler

Scalable web architectures & high-performance systems for demanding business logic.

const engineer = {
  name: 'Marc Itzenthaler',
  role: 'Senior Full-Stack Engineer',
  focus: ['Scalability', 'Performance', 'Architecture'],
  tools: ['React', 'Next.js', 'Symfony', 'Node.js'],
  delivery: () => transform(complexIdeas)
    .into(performantSolutions)
};

About me

For over 15 years, I have been building scalable web solutions for companies across various industries. As a freelancer, I combine full-stack development with pragmatic DevOps — from architecture to production deployment.

15+ years experience
Full-Stack & DevOps
API-first architectures
Hands-on delivery

Services

Modern Web Architectures

Design and implementation of future-proof system architectures focused on scalability and maintainability.

Headless & Composable Frontends

Modular user experiences with React and Next.js — decoupled for maximum performance.

Backend & API Development

Robust, high-performance interfaces with PHP/Symfony, ApiPlatform, or Node.js.

DevOps & Cloud

CI/CD pipelines, Docker containerization, and cloud orchestration with Kubernetes.

Highlights

Case Study: Performance

E-Commerce Relaunch Under Time Pressure

Problem: Severe performance degradation during traffic peaks.
Approach: Migration to Next.js & headless architecture.
Result: Significantly faster load times and stable conversion rates.

Case Study: Scalability

Digital Counseling Platform

Problem: Infrastructure at its limit with growing user numbers.
Approach: Orchestration with Kubernetes & microservices.
Result: Highly available for thousands of concurrent users.

Case Study: Integration

API Platform & Integrations

Problem: Inefficient data flows due to legacy silos.
Approach: Central API design with Symfony & ApiPlatform.
Result: Automated data exchange, less manual effort.

Case Study: Modernization

Migration & Modernization

Problem: Outdated systems with high security risks.
Approach: Incremental refactor (Strangler Fig pattern).
Result: Modern tech stack without operational downtime.

Skills

Frontend

ReactTypeScriptNext.jsTailwind CSSSCSS

Backend

PHPSymfonyApiPlatformNode.jsNest.js

Database

MySQLMariaDBMongoDBDoctrine

DevOps

KubernetesDockerGitHub ActionsCI/CD

Tools

GitPHPUnitCypressPHPStormVS Code

15+

Years of experience

50+

Projects

99.9%

Uptime focus

100%

Engineering focus

Ready for the next architecture level?

Let's discuss how I can solve your technical challenges with senior hands-on expertise.

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