Senior Full-Stack Developer Needed – NestJS + React/TypeScript Fuel Levy Pricing Engine for Rideshare Platform

Job Title: Senior Full-Stack Developer Needed – NestJS + React/TypeScript Fuel Levy Pricing Engine for Rideshare Platform Job Description: I am looking for a highly skilled full-stack developer to build the first production-ready version of a vehicle-specific fuel levy / energy levy pricing engine for my rideshare platform based in Queensland, Australia. This system must be designed as a secure backend-driven pricing engine, where the commercial logic remains private on the server and is not exposed to the browser. The purpose of the system is to calculate a fair trip-based fuel or energy levy using approved vehicle data and live/local fuel pricing inputs, with support for petrol, diesel, hybrid, and EV vehicles. The backend must be built using Node.js, NestJS, TypeScript, Prisma, and PostgreSQL, and the frontend must be compatible with ReactJS + TailwindCSS v3 + TypeScript. This is not a simple calculator widget — I need a clean, modular, scalable backend foundation that can later integrate into a larger commercial transport platform. Project Scope: The developer will be responsible for building the backend architecture and core API endpoints required for the levy engine. This includes creating a proper NestJS project structure with separate modules for vehicles, fuel pricing, and levy calculations, along with Prisma models, DTOs, controllers, services, validation, and environment configuration. The system must securely store approved vehicle records including make, model, year, fuel type, registration, and official consumption data such as L/100km for petrol/diesel/hybrid vehicles and kWh/100km for EVs. A fuel pricing layer must be built to support ingestion of Queensland fuel pricing data, including storing price snapshots by postcode/suburb/fuel type and returning the most relevant local fuel price or fallback value where needed. The levy engine itself must calculate values using actual formulas based on vehicle-specific approved data and local price inputs, return a structured breakdown, and log each calculation to the database. Required Formula Logic: For petrol, diesel, and hybrid vehicles, the levy must be calculated as: chargeableKm × (officialLPer100Km / 100) × fuelPricePerLitre For EVs, the levy must be calculated as: chargeableKm × (officialKwhPer100Km / 100) × electricityRatePerKwh Where chargeableKm = tripKm + pickupKm. The backend must retrieve the approved vehicle, retrieve the relevant local pricing, calculate the levy, round sensibly, and save the calculation log. Core Deliverables: I expect the developer to deliver a proper backend codebase with a clean folder structure, complete Prisma schema, NestJS modules, DTOs, database models, service logic, environment setup, and working API endpoints such as: create vehicle, get vehicle, create fuel snapshot, get local fuel price, and calculate levy. I also want sensible fallback behaviour where local data is missing, validation that only approved vehicles can be used in levy calculations, and code written in a professional, maintainable, production-conscious style. The frontend UI itself is not the focus of this job, but the API must be fully compatible with a React/Tailwind frontend. Important Requirements: The pricing logic must remain server-side and must not be exposed publicly. The developer should understand secure API design, modular NestJS development, Prisma/PostgreSQL integration, and scalable architecture. Strong TypeScript skills are essential. Experience with transport, dynamic pricing, logistics, fleet systems, or financial calculation engines would be highly regarded. I want someone who can think commercially and architect this properly, not just throw together a basic demo. Bonus Points If You Can Also Help With: Future integration of real Queensland fuel price data feeds, admin approval workflows for vehicle validation, pricing version control, anti-gaming protections, fallback regional pricing logic, and broader transport platform API architecture. What to Include in Your Proposal: Please send examples of previous work using NestJS + TypeScript + Prisma, especially any systems involving pricing logic, transport/logistics, SaaS platforms, or secure backend APIs. Also explain how you would structure this project, how you would keep the pricing engine private and secure, and whether you can assist with future stages after this first backend foundation is complete. Project Preference: I prefer a developer who can build this in a way that is scalable for long-term use, because this may lead to additional work for the full pricing engine, rider pricing flows, driver payout logic, admin dashboards, and broader platform APIs.

Projektin tunnus (ID): 40279517