I’m Alexandra Costin, a Computer Science graduate working across
website design, app production, backend development, cybersecurity
and ethical penetration testing. I build clean, responsive and practical
digital products with strong structure, modern interfaces and reliable
functionality.
My technical skills include Java, React, Python, backend systems,
full-stack development, web application security and pentesting
methodology. I focus on creating digital products that are
user-friendly, scalable and built with security in mind from the start.
Choose what you want to build and see the type of work I can help
plan, design, develop or review from a security perspective.
Website Production
Design + Build
Responsive page design
Clean user experience
Frontend build and structure
Launch-ready layout
What I Offer
I help turn ideas into clean, modern and reliable digital products,
from visual design and backend functionality to authorised penetration
testing and security-focused improvements.
WEB
Website Production
Modern, responsive websites designed for individuals, businesses,
portfolios, landing pages and digital project ideas.
Personal websites and portfolios
Business landing pages
Responsive mobile-friendly layouts
Frontend and backend functionality
APP
App Production
Mobile app concepts and early-stage builds designed around clear
user flows, clean interfaces and practical functionality.
App idea planning
Mobile interface design
iOS and Android app foundations
Prototype-style app development
PEN
Penetration Testing
Authorised security testing for websites and applications, focused
on identifying weaknesses and improving the overall security of a
digital product.
Web application security review
Authorised vulnerability testing
Authentication and access checks
Clear findings and improvement guidance
How I Work
A simple process for turning an idea into something structured,
modern, secure and usable.
01
Understand the idea
I start by understanding what you want to build, who it is for,
what the goals are and what the product needs to do.
02
Plan and design
I shape the structure, pages, user flow and visual direction so the
product feels clear, modern and easy to use.
03
Build and secure
I develop the product, connect the required functionality, review
the security side and improve the final result with polish.
Selected Work
A quick preview of projects, experiments and digital ideas. The full
collection will live on the portfolio page.
Personal Website
catsoncars.work
A personal website and digital space for projects, notes,
development progress and portfolio work.
Have an idea for a website, app or security review?
Let’s turn it into something modern, clean and useful. Whether you
need a website, app concept, backend functionality or authorised
penetration testing, I can help shape, build and improve it.