Million-URL SEO Indexation Optimization

I run a dynamic site that can spin up millions of unique URLs, yet too many of those pages are never making it into Google’s index. Although I already push XML sitemaps through Search Console and handle basic link building, the scale of the project demands deeper technical SEO expertise... (Budget: $250 - $750 USD, Jobs: BigQuery, Content Strategy, Data Analysis, Internet Marketing, Link Building, Search Engine Marketing, SEO, Website Audit)