Jack Kollar
Software Engineer focused on .NET, C#, Java, Javascript
New to Contra
Jack is ready for their next project!
Next.js
Frontend Engineer
Backend Engineer
+6
📊 Data Dashboard & Internal Automation MVP Development
$75/hr
ExpressJS
Frontend Engineer
Backend Engineer
+6
Subscription-Based SaaS MVP - Full Stack React/Node/Express
$75/hr
C#
Dot Net Backend Developer
Backend Engineer
+6
Legacy System Modernization & Migration (Java / .NET / C#)
$75/hr
C#
Dot Net Backend Developer
Backend Engineer
+6
Enterprise Backend & API Development (Java/Spring Boot/.NET/C#)
$75/hr
.NET
Frontend Engineer
Backend Engineer
+6
Scalable Marketplace & Platform Development (Next.js/MERN/.NET)
$75/hr
HTML5
Dot Net Backend Developer
Backend Engineer
+6
API-First Web Application Development - .NET, Node.js, or Python
$75/hr
AWS
Dot Net Backend Developer
Backend Engineer
+6
Legacy System Modernization - Next.js, MERN, or .NET Core
$75/hr
JavaScript
Frontend Engineer
Backend Engineer
+6
Custom SaaS Dashboard & Admin Panel (Next.js / React /)
$75/hr
JavaScript
Backend Engineer
AI Engineer
+6
AI-Powered SaaS MVP Development - Next.js, MERN, .NET, Python
$75/hr
JavaScript
Backend Engineer
AI Engineer
+5
AI Integration for Existing Applications
$75/hr
LangChain
Backend Engineer
AI Engineer
+5
AI Chatbots & Intelligent Assistants
$75/hr
ASP.NET
Dot Net Backend Developer
Backend Engineer
+6
Enterprise-Grade .NET Application Development
$75/hr
Next.js
Frontend Engineer
Backend Engineer
+6
Modern Web Platform Development (Next.js / React)
$75/hr
.NET
API Integration
API Development
+5
High-Performance API Development & Integration
$75/hr
FastAPI
Dot Net Backend Developer
Backend Engineer
+6
Full-Stack SaaS Development (MERN / Next.js / .NET)
$75/hr
C#
Dot Net Backend Developer
Backend Engineer
+5
Custom AI Solutions & Automation Systems - Python, .NET
$75/hr
ExpressJS
Frontend Engineer
Backend Engineer
+6
AI-Powered Web Application Development
$75/hr