Ep.4 | Shopify-series | Shopify Functions (Rust and Javascript)

In this fourth episode of our Shopify series on "Off the Bench," the team at 6th Man dives deep into the high-stakes world of Shopify Functions. When a customer hits the "checkout" button, a race begins. To keep the shopping experience instant, Shopify mandates that all customizations—known as Shopify Functions—must execute in five milliseconds or less. This episode explores how developers and high-performing merchants navigate this strict "sandbox" to build powerful, server-side logic that remains invisible to the shopper. In this episode, we discuss: What are Shopify Functions? Understanding these lightweight, precision instruments that live within the checkout and cart workflows. Rust vs. JavaScript: A comprehensive breakdown of the two primary languages used for Functions. We explain why Rust is the "gold standard" for heavy computation and large carts (50+ items), while JavaScript offers a faster development cycle for simpler, straightforward logic. The Decision Framework: How to determine if you even need a Function, or if your requirements are better served by Shopify Flow, custom apps, or webhooks. The WASM Sandbox: A look at the technical boundaries, including the 256KB size limit and the "no external network access" rule that ensures checkout security and reliability. Design Principles for Success: How to organize data effectively and plan for exceptions to ensure your customizations never block a sale. Throughout the episode, we also share more about what we do at 6th Man. Based in Ghent, our specialist Shopify team builds custom stores, handles complex migrations from platforms like WooCommerce and PrestaShop, and optimizes existing stores through dedicated SEO and CRO strategies. Whether you are a merchant looking to scale or a developer weighing implementation strategies, this episode will equip you with the knowledge to choose the right path for your Shopify store. Don't forget to subscribe! If you have questions about implementing these strategies on your own site, do not hesitate to contact 6th Man.