When searching for an Upwork clone script, it's crucial to prioritize factors like scalability, customization, user experience, and robust payment integrations. Here's a breakdown of what to consider and some vendors that appear to provide those services:

Key Considerations:

Scalability:
The script should handle increasing user traffic and data volume as your marketplace grows.
Look for solutions built with scalable technologies.
Customization:
Ensure the script allows for extensive customization to match your branding and specific business needs.
White-label solutions are often preferred.
User Experience (UX):
A clean, intuitive interface is essential for both freelancers and clients.
Mobile responsiveness is a must.
Payment Integrations:
Secure and reliable payment gateways (e.g., Stripe, PayPal) are critical.
Support for multiple currencies is essential for a global marketplace.
Multi-lingual Support:
If you plan to have a global presence, then multiple language support is a must.
Security:
Robust security features to protect user data and financial transactions.
Vendors and Solutions:

Based on the search results, here are some vendors that offer Upwork clone scripts:

Apptunix:
They emphasize customizable solutions, advanced technology stacks, and 24/7 technical support.
They highlight scalability and multi-language support.
They speak of creating apps for Ios and Android, in addition to web platforms.
Oyelabs:
They focus on providing feature-rich clone scripts with secure payment systems.
They also emphasize on platform wide analytics, and fraud detection.
They also offer mobile app solutions.
Logicspice:
They offer freelance marketplace scripts with features like secure login, project management, and payment gateways.
They offer multi language support.
They also offer a subscription based model.
Migrateshop:
They provide Upwork clone scripts that allow for the creation of a freelance service marketplace.
Important Notes:

For more details, feel free to book a call.