Prestashop developer

Looking for a Prestashop developer for on/off work related to our Prestashop e-commerce websites.

Will need to assist us in simple to more complex tasks like:
- module & theme installation and modification
- bug fixing
- technical support
- assist with server/hosting issues
- payment systems integration
- make copies of stores to other domains
- speed optimization
- security, backup and update systems
- module creation, if necessary
- upgrades and migrations
- etc.

MUST HAVE experience and be comfortable with:
- Back-end and front-end work
- Server issues and migrations
- Technical SEO optimization
- Very good domain of the English or Portuguese language (for communication)
- Reliability, availability and professionalism

- Domain of other languages is also appreciated
- App creation skills are also appreciated for future work