Mario Colic
Full Stack Developer
I build production apps in the Shopify ecosystem at Shop Circle — from storefront to infrastructure. Focused on shipping fast, scalable software that merchants rely on daily.
Passionate about building things that matter
I'm a full stack developer at Shop Circle on the Releasit Apps team. I build and maintain production Shopify applications end-to-end — from the storefront experience to the backend infrastructure. I care about writing clean, maintainable code and shipping products that solve real problems for real people.
When I'm not coding, you'll find me gaming, binge-watching something on Netflix, or just vibing.
Full Stack Development
Building performant web applications across the entire stack.
Shopify Ecosystem
Deep expertise in Shopify app development and storefront customization.
Infrastructure
Designing and managing scalable data layers and cloud services.
Development Experience
Shop Circle
Releasit AppsBuilding and maintaining production Shopify apps serving 150k+ merchants worldwide. Working across the full stack — from React frontends to backend infrastructure — shipping features, resolving complex bugs, and owning entire app lifecycles.
Shop Circle
Releasit AppsSpecialized in customizing Shopify apps to meet merchant needs using JavaScript and CSS. Leveraged deep knowledge of in-app features and Shopify's data flow to deliver tailored solutions and optimize user experiences.
Things I've Built
From Shopify apps to full-stack platforms — a selection of my work
Professional Work
Releasit COD Form & Upsells
1-Click Cash on Delivery order form with pre/post-purchase upsells, downsells, and quantity offers to boost conversion and AOV. Features OTP phone verification, A/B testing, multi-currency support, and event tracking across Facebook, TikTok, Google, Pinterest & Snapchat.
Releasit COD Fee & Verify
Set COD fees, discounts, and conditional rules by country, product, or order value. Verify orders with WhatsApp OTP to block fake checkouts and reduce RTO. Collect partial COD payments upfront with full payment tracking and balance visibility.
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Releasit Bundle
In DevelopmentProduct bundling app with quantity offers, related product upsells, cross-sells, and custom discount strategies to increase AOV. Built from scratch with analytics, A/B testing, and highest-level Shopify compliancy.
Birthday Venue Platform
Coming SoonFull-stack booking platform connecting parents with kids' birthday venues. Venue owners create customizable profiles with real-time slot availability, pricing, and booking management. Parents search, filter, and book directly — with confirmation and verification systems built in.
Notable Side Projects
Mini Shop
Multi-tenant e-commerce platform inspired by Shopify — built from scratch to deeply understand how Shopify works under the hood. Full ecosystem including storefront rendering, tenant isolation, database architecture, logging, and error monitoring.
Shopify Debug Extensions
Chrome extensions built to enhance our support team's workflow — live storefront debugging, app diagnostics, and automated code changes directly from the browser.
Discord Automation Bot
Discord bot with admin controls, scheduled messaging, game API integrations, and automated response systems. Hosted 24/7 via Railway.
Let's Build Something Together
Got a project in mind, want to collaborate, or just want to say hi? I'm always open to new opportunities and interesting conversations.