Magento 2 Developer — Live LTL Freight Rate Calculator for B2B Industrial Store

We're an established B2B industrial safety and PPE distributor running a 350,000+ SKU catalog on Magento 2 (Open Source) with the Hyvä theme. A large and growing share of our orders ship LTL (less-than-truckload, palletized freight) rather than small parcel — spill containment pallets, IBC equipment, fall-protection systems, bulk consumables, and similar heavy/bulky goods. The problem we need solved We can't reliably present accurate LTL freight rates to customers in real time. Today our LTL handling is [describe current state — e.g., "flat-rate guesses," "Call for Freight," "manual quoting after the order," "a generic table-rate"], and it's costing us conversions on freight-eligible carts and eroding margin when our estimate is wrong. We're looking for someone who has built live LTL rating on Magento before and understands that freight is fundamentally different from parcel — freight class, accessorials, pallet building, and dimensional rating all matter. Scope of work Deliver real-time LTL freight quotes in the cart and at checkout, calculated from actual order contents and destination, with sensible handling of the realities of freight: Live LTL rating via your recommended path — direct carrier APIs (Estes, Old Dominion, XPO, SAIA, R+L, FedEx Freight, etc.), a rating aggregator (SMC³, Banyan, project44, GlobalTranz/Worldwide Express, Echo), or a Magento freight extension (ShipperHQ, Eniture LTL Freight Quotes). We're open to your recommendation — tell us what you'd use and why. Product-level freight data: consume freight class (NMFC), weight, and dimensions per SKU. Propose a practical strategy for the many SKUs where this data is incomplete (defaults, category-level rules, density-based class calculation, flagging gaps). Pallet / handling-unit logic: how multiple line items combine into pallets and how that's passed to the rating engine. Accessorials: liftgate, residential delivery, limited-access, inside delivery, notify-before-delivery — selectable or auto-detected where possible. Markup / margin rules applied to returned carrier rates (flat, percentage, or tiered). Mixed carts: orders containing both parcel and LTL items rated correctly together. Graceful fallback when a live rate isn't returned (timeout, no coverage, missing data) — never a broken checkout. Clean presentation in the Hyvä cart and checkout [note whether you run Hyvä Checkout or Luma/default checkout]. Required experience Strong Magento 2 backend development (PHP), including custom shipping carrier methods / rate models. Demonstrable prior work integrating LTL freight rating (carrier APIs, an aggregator, or ShipperHQ/Eniture) — please cite specific projects. Working knowledge of freight class / NMFC, accessorials, and dimensional/density rating. Comfortable working in a live, high-SKU production store without breaking checkout.