Senior Backend Engineer / Software Architect — API & Business Logic Platform

We are looking for a senior backend engineer/software architect to help us transition a working Airtable-based business operations platform into a fully custom application over time. We currently operate a sophisticated internal system built with Airtable, Make.com, Hetzner-hosted services, forms, automations, and integrations. It is actively used every day by our operations team and field employees. We do NOT want to scrap the existing system and rebuild everything at once. Instead, we want to use Airtable as our current production database while beginning to build a permanent API and Business Logic Layer between Airtable and our future custom web/mobile interfaces. As custom components are developed and proven, we will gradually move functionality out of Airtable and eventually migrate the underlying database to something like PostgreSQL. We need someone who can help us architect this transition correctly, not simply write endpoints. Our platform manages a highly interconnected operational network involving customers, vessels, captains, marinas, employees, work orders, scheduling, service history, inventory, fleet, payments, referrals, physical assets, and many relationships between them. We are looking for someone experienced with: Backend/API architecture Complex business logic and workflows Relational data modeling / PostgreSQL Domain-driven design Authentication and role-based permissions Event-driven processes, background jobs, and webhooks Third-party integrations Audit/history requirements Incremental migration from an existing production system Designing software that can eventually support web, mobile, and AI interfaces The immediate objective is to review our existing architecture and workflows, help define the permanent backend architecture, and begin building the BB Command API/business logic layer while Airtable continues functioning underneath it. This is not a website project or a simple Airtable integration. We are looking for an experienced engineer who can help us design the foundation of a long-term custom operational software platform while we gradually replace the existing low-code scaffolding.