If you’re looking for free resources to learn advanced Shopify development, here are some options you can consider:

1. Shopify Developer Documentation: The official Shopify Developer Documentation is an excellent resource for learning advanced Shopify development. It provides detailed information on various topics, including theme development, app development, APIs, and more. You can access the documentation at https://shopify.dev/docs.

1. Shopify Partner Academy: Shopify offers free online courses through the Shopify Partner Academy. While some courses require a Shopify Partner account, many resources are available to the public. The courses cover a wide range of topics, including theme development, app development, and Shopify best practices. You can access the Shopify Partner Academy at https://www.shopify.com/partners/academy.

1. Shopify Community Forums: The Shopify Community Forums are a valuable resource for developers. You can find answers to common questions, participate in discussions, and learn from experienced developers. The forums cover various topics related to Shopify development, and you can access them at https://community.shopify.com/c/Shopify-Community/ct-p/en.

1. YouTube Tutorials: YouTube is a great platform to find free tutorials on advanced Shopify development. Many experienced developers and Shopify experts share their knowledge and tips through video tutorials. Channels like Shopify, The Unofficial Shopify Podcast, and Codecourse offer Shopify-related content.

1. Shopify App Store: Exploring the Shopify App Store can be helpful for learning advanced development techniques. Analyze the apps available on the store, examine their code (if they provide it), and study their functionalities to gain insights into advanced Shopify development practices.

1. GitHub: GitHub is a popular platform for developers, and it hosts numerous open-source Shopify projects. By exploring these projects, you can learn from the codebase, review implementations, and gain practical knowledge of advanced Shopify development techniques. Search for “Shopify” on GitHub and filter by repositories to find relevant projects.

1. Shopify Meetups and Webinars: Keep an eye out for virtual meetups and webinars organized by Shopify or the Shopify developer community. These events often cover advanced topics, provide insights from experts, and offer opportunities to connect with other developers.

Remember, advanced Shopify development involves a deep understanding of web technologies, including HTML, CSS, JavaScript, and Liquid (Shopify’s templating language). It’s beneficial to have a strong foundation in these areas before diving into advanced topics. As you progress, practice building custom themes, explore the Shopify API, and experiment with app development to enhance your skills.