Question: I'm looking for a platform that supports multiple languages and frameworks for building high-performance applications.

If you need a platform that spans languages and frameworks for building high-performance apps, Neon is a good choice. Neon is a serverless platform that lets you build fast, scalable and reliable apps with Postgres as its database. It supports multiple languages and frameworks, along with features like branching, CI/CD and schema migrations. Neon's pricing tiers are tiered, including a free tier, so it can accommodate a range of development needs.

Another good option is Xata, a serverless data platform built on PostgreSQL. Xata supports a broad range of tools and frameworks like Astro, Next.js, Nuxt.js and more. It also offers features like zero-downtime schema migrations, full-text search with Elasticsearch and AI integration. The service also offers a generous free tier with high availability, data storage and AI queries, so it's good for projects that are growing.

If you want an open-source alternative to Firebase, Supabase is worth a look. It includes a Postgres database, user authentication, instant APIs and real-time data synchronization. Supabase supports frameworks like Next.js, Svelte and Flutter, and includes a built-in user management system and edge functions for custom code. The service also offers a free tier with unlimited API requests and abundant storage.