Freight Platform Dev — Next.js/TS/Postgres

We have an early-stage freight logistics platform that was rapidly put together using AI to prove out a concept. Right now, it's a fragile prototype that isn't fully usable, and we need a sharp developer to help establish a stable foundation. We want to clean up the architecture and build the core flows out properly before layering on advanced automation and AI features. The repository uses Next.js 16 (App Router), TypeScript, Tailwind 4, Prisma 6, and PostgreSQL. It includes early scaffolding for core TMS flows — quoting, booking, tracking, invoicing, and a custom pricing engine. Your job is to help stabilize this codebase, build out real-world third-party shipping API integrations, and structure a clean multi-role marketplace around it. Where the existing structure needs to change, we're open to your input — bring your ideas and we'll map out the best path forward together. Our preference is to build forward on what's there rather than start over in a different stack. What we're looking for: Reliable Engineering: Code that handles real-world data and edge cases, not just the happy path. Money is handled strictly in integer cents, and errors in rate calculations or booking requests have real business impact. Third-Party API Integration: Experience dealing with messy external APIs — handling auth, retries, rate limits, webhooks, and preventing double-bookings or duplicate charges during failures. Fast Learning & Comprehension: Ability to look at industry platforms we use daily (TMS systems, load boards, carrier portals) and understand how and why they work. We'll walk you through the ones we work with. AI-Assisted Development: Highly encouraged! This codebase was built with AI tooling, so feel free to use whatever speeds up your workflow. You'll just need to own the code you submit and be able to explain how it works. Multi-Role Systems: Comfort with permission models where records serve different purposes for shippers, carriers, and internal admins. Experience with multi-sided marketplaces is a strong plus. Proactive Communication: Clear, direct updates. If something is blocked or breaking, let us know early so we can tackle it together. Availability: 30 to 40 hours per week, with at least a few hours of daily overlap with Eastern Time (NY). Budget: $5–$7/hour for a strong generalist willing to learn the logistics domain; $7–$10/hour if you already have relevant API and marketplace experience. We're happy to pay the top of that range for the right person. Note: Solo developers only — no agencies or team bidding. How We Start We'll kick things off with one small task in the real codebase — a few hours, paid at your rate, on work we keep — to see how we work together. If it's a good fit, we can transition into an ongoing weekly contract with plenty of interesting roadmap items ahead (mobile apps, advanced automations, AI workflows). Application Questions Please keep your answers concise and include them in your proposal: 1. Start your reply with the word PALLET so we know you read through the details... 2. API Integration Strategy: When integrating multiple disparate third-party carrier and logistics APIs with varying schemas into a single unified provider interface, how do you structure the abstraction layer? (Code snippets or an architecture breakdown are welcome). 3. API Troubleshooting: Link to something you've built that interacts with an external API. Briefly share what went wrong with it at some point and how you resolved it. 4. Availability: Confirm your available hours per week and your working hours in Eastern Time (NY).