Senior Software Engineer - Back-End

### The Company You’ll Join At Rebuy, we’re on a mission to revolutionize shopping with intelligent, personalized experiences that wow customers around the globe. As a fully remote team, we power some of the fastest-growing DTC brands like Aviator Nation, Liquid Death, Magic Spoon, Blenders, Laird Superfoods, Primal Kitchen, and many more. We believe in ownership, drive, and empathy, and strongly uphold that every team member plays a vital role in shaping the future of intelligent commerce. Our culture thrives on collaboration, creativity, and genuine passion. ### The Problems You’ll Solve As a Senior Software Engineer (Back-End), you’ll own some of the most consequential systems at Rebuy. Your primary focus will be our billing and payments infrastructure — the engine that determines how merchants are charged, how partners get paid, and how financial balances flow across our entire product suite. This role requires deep PHP and Go expertise, careful architecture, and sound judgment. You will also contribute to a significant technical migration: moving our legacy Code Igniter 2 codebase to Code Igniter 4. This migration requires hands-on PHP expertise and cannot be deferred. ### Key Responsibilities - **Billing & Payments Architecture:** Design and build Rebuy’s centralized billing system that handles merchant billing, partner payments, and customer-facing charges. - **Build Robust APIs:** Design and implement secure, well-structured APIs in PHP and Go to power billing events, payment processing, and financial data flows across our platform and Shopify integrations. - **Legacy Modernization:** Lead and contribute to the migration of our Code Igniter 2 codebase to Code Igniter 4, ensuring high-quality execution with real business dependencies. You won’t be handed a sprawling list of tasks on day one. You’ll be trusted to grow into this role — and rewarded when you do.