Migration from CakePHP to Next.js

I'm in need of a talented Next.js developer for a project involving a range of tasks including Backend development, Frontend development, and API integration. If you're well versed JavaScript, this could be the ideal project for you.

Project Description:
Our project Movesbook, a fitness and sports activity tracking platform, was built for athletes, coaches, teams, clubs, and fitness enthusiasts to record, manage, and analyze their workouts in Italy.
The previous version of the platform was developed using CakePHP. We migrated many parts of the original source to a modern stack using Next.js and Prisma to improve performance, scalability, and maintainability.
But the migrated version has some vulnerablilities in security and also in performance, too.

Performance Metrics
Metric                  Target
Concurrent Users        10 Thousands
Processing Throughput   Scalable
Memory Efficiency       Optimized
LCP                      ≤ 2.5 s
INP                      ≤ 200 ms
CLS                      ≤ 100 ms    
Page Load Time           ≤ 2.5 s

Experienced Next.js Developer — Ongoing Project  
Rate: $30–$35/hour, 40 hours per week

Performance goals
Our aim is to support growth toward 10,000 concurrent users while targeting:
LCP: ≤ 2.5 seconds
INP: ≤ 200 ms
CLS: ≤ 0.1
Page load time: ≤ 2.5 seconds

What we’re looking for
Strong experience with Next.js, React, and JavaScript
Good working knowledge of PHP and CakePHP
Experience with Prisma and relational databases
Strong API integration skills
Experience implementing payment gateways
Confidence working with and improving an existing codebase
A focus on secure, scalable, maintainable solutions

Requirements
Strong Next.js / React experience
Good PHP / CakePHP knowledge
Experience with Prisma and databases
Strong API integration skills
Payment gateway integration experience
Comfortable working with and improving an existing codebase

You Should Have
Hands-on experience building and maintaining production applications with Next.js and React
Strong JavaScript skills and the ability to work across frontend and backend
Experience with Prisma, databases, API integrations, and payment systems
The ability to investigate unfamiliar code, identify risks, and deliver reliable improvements
Clear communication and a thoughtful, security-conscious approach to development

Nice to Have
Experience with PHP and CakePHP
Experience migrating a legacy application to a modern stack
Familiarity with performance optimization and Core Web Vitals
Experience with fitness, sports, coaching, or activity-tracking products
Experience supporting applications with high traffic or concurrent usage
Experience with fitness, sports, or activity-tracking platforms is a plus.

This is an ongoing project with potential for long-term collaboration. You should be comfortable working across both frontend and backend.