Multi-Tenant Organic Social Posting Integration for X, YouTube, LinkedIn, TikTok & Meta

We are building a SaaS platform that allows multiple users/tenants to create and publish organic social media content directly from our app. We are looking for an experienced developer or technical consultant who can help us design and/or implement the best approach for posting on behalf of users to: X / Twitter YouTube LinkedIn TikTok Meta: Facebook Pages and Instagram The goal is to allow each user to securely connect their own social accounts and then publish posts, videos, images, captions, and other content from our platform. We are not sure yet whether the best approach is to integrate directly with each platform’s API or use an aggregator such as Ayrshare, SocialPilot API, Buffer API, Publer, Metricool, or another provider. We want someone who can help us evaluate the best technical path and ideally help implement it.