Laravel/Statamic migration of 50k-entry NL/FR CMS

We are moving a bilingual (NL/FR) editorial B2B platform off Umbraco 13.7.2 (.NET 8, SQL Server 2016, IIS) onto an open source Laravel platform, and we are looking for the party that will build it. This post is the selection round. We choose the build partner on the basis of the written proposals we receive. THE PLATFORM An editorial B2B platform in a specialised professional sector. 65 content type aliases, covering news articles, a company directory, a project portfolio, a vacancy board, product listings, events, webinars and podcasts, a block based newsletter builder, an awards programme with its own sub site and public submission portal, two tender sub sites, an advertising system with targeting through an external ad platform API, a member portal with self service CRUD, and a login gated statistics module with seven report types fed by a daily automated job. Volumes: 36,160 content nodes, 49,585 published language versions (30,969 NL, 18,616 FR), around 35,000 active URLs. Every field is stored per language, so there is no shared field between NL and FR today. Statamic is our preference for the content layer, but it is not fixed. A well argued alternative, a different Laravel CMS or a fully custom Eloquent model, is equally welcome. WHAT WE EXPECT FROM YOU One proposal, delivered as a single PDF, covering: 1. Hours and cost for the three tiers in section 7 of the scope document: (1) functionally 1 to 1 on the existing design, (2) plus a refreshed design, (3) plus a fully new design. The functional scope is identical across all three. 2. Your recommended technical approach, with your reasoning. 3. Your content migration strategy for the 49,585 bilingual entries, and whether you would keep the per language field model or move to an origin model. 4. Your phasing and timeline, and the testing and acceptance criteria you propose. 5. Two or three comparable reference projects: scale, multilingual, CMS migration. 6. The assumption you make on each of the eight open items in section 8 of the scope document, and what it does to your estimate. Two hard requirements: all existing URLs keep working on the same route with no loss of organic traffic, and the lead forwarding flow on article and company pages keeps working 1 to 1 from day one. PRACTICAL • Read the attached scope document first. It covers the stack, data model, volumes, modules, SEO and URL structure, and the open items. • One PDF per candidate. A proposal spread over several files, or written only in the Upwork message box, will not be assessed. • An NDA is available, including a live walkthrough of the existing platform. • The build itself is a project of at least 6 months. • Communication in English or Dutch. A Europe/Brussels time zone is a plus. • Questions about the scope are welcome before you write your proposal.