We are looking for a senior Technical SEO freelancer for BiGpdf.com, a JS-heavy international PDF tool portal available in 21 languages. This is not a content SEO or link-building role. Important: this posting is for Phase 1 only. Phase 1 is a tightly scoped fixed-price sprint focused on audit, root-cause analysis, prioritization, and a proof-based technical SEO foundation plan. Any follow-up work will depend entirely on the quality, clarity, and evidence of the Phase 1 delivery. Possible follow-up phases may include implementation review, validation re-crawls, and SEO quality control, but these are not part of this posting. We need a hands-on expert who can audit staging and production, identify and prioritize root causes, recommend the right rendering and indexation setup, improve canonical, hreflang, and sitemap logic, and deliver a clear, evidence-based validation package. Phase 1 should include: - Technical SEO audit of staging and production - P1 / P2 / P3 prioritization - rendering strategy recommendation - canonical and hreflang strategy for 21 languages - sitemap rebuild concept - proof package and Definition of Done (DoD) Please apply only if you have proven experience with JS-heavy SaaS, tool portals, international SEO, rendering and indexation issues, and validation using Screaming Frog and Google Search Console. Experience with GA4 / Google Analytics is a plus. Mandatory: include a short mini-case covering likely root causes, rendering strategy, hreflang/canonical setup, and the proof package you would deliver within 14 days. Please also include 2–3 relevant references, your role in those projects, your hourly rate, your availability, and your realistic start date.