Magento Website Upgrade with Custom Extensions & Themes

I'm looking for a Magento expert to upgrade my current Magento 2.x website. You should have a strong background in Magento development and experience with upgrading websites. The successful candidate will have to deal with both custom extensions and themes.

Key Responsibilities:
- Upgrade the website to the latest Magento version.
- Ensure that both custom extensions and themes are compatible with the new version.
- Implement performance optimization techniques for the upgraded website.
- Enhance security features.

Ideal Skills:
- Strong experience in Magento development.
- Proven track record of upgrading websites.
- Proficient in dealing with both custom extensions and themes.
- Excellent knowledge of performance optimization and security features in Magento websites.