The shift to relational backends in October 2026

Security and data models

Supabase uses Postgres to provide relational database power, whereas Firebase relies on a NoSQL document model. For B2B SaaS projects with complex roles and billing, Supabase provides a more direct path because it handles relational data natively. Firebase users must manage data integrity within their application code because Firestore lacks a relational schema. You should test your RLS policies by signing in as every specific role to ensure no data leaks occur. Supabase Row Level Security allows developers to define rules directly in the database. This prevents unauthorized access even if an API bug exists. Firebase uses Security Rules to match patterns against data paths in Cloud Firestore. Firebase now offers Postgres access through SQL Connect, which runs on Cloud SQL for PostgreSQL and uses GraphQL for queries and mutations. Supabase uses pgvector for AI-driven features, storing embeddings in the same database as the rest of the data. Firebase connects application data to Gemini models like Gemini 3.8 Flash or Gemini 4 Argon without custom API wrappers. The user management dashboard in Supabase is clean. Flutter developers find the Appwrite SDK particularly polished for mobile-first products.

Scaling costs and resource constraints

Pricing models create significant friction for teams choosing between these platforms. Supabase provides a free tier with 50,000 monthly active users and 500 MB of database storage. The Pro tier starts at $25 per month and includes 8 GB of disk and 100,000 monthly active users. This tier includes $10/month in compute credits, which covers one project on Micro compute. However, the jump to the $599 Team tier is brutal for startups needing SOC2 compliance. Appwrite provides a different scale, with a free tier that includes 75,000 monthly active users and never pauses projects. The Appwrite Pro plan costs $25 per month and includes 200,000 monthly active users. Firebase utilizes a consumption-based model where every document read, write, delete, and update contributes to the monthly bill. Firebase also requires users to upgrade to the Blaze plan to deploy Cloud Functions.

Infrastructure requirements also vary. Appwrite requires 2GB of RAM to run its containerized stack, while PocketBase runs on only 0.05GB of RAM. Developers building applications with high-intensity background tasks often face the frustration of migrating away from Supabase because the current 2-second CPU limit for Edge Functions proves insufficient for real-world workloads. Supabase Edge Functions run on Deno and provide sub-100ms cold starts. These functions work well for webhooks and payment callbacks. Supabase real-time subscriptions use an Elixir-based server that listens to the PostgreSQL replication stream. Firebase provides a different real-time experience where Firestore listeners send an initial snapshot and then an update every time the data changes. Appwrite Cloud, which became generally available in 2024, manages infrastructure automatically and allows teams to scale specific components, like worker containers, based on the volume of background tasks.

The October 30 migration risk

A major change arrives on October 30, 2026, when Supabase stops granting automatic permissions to the anon and authenticated roles, as well as the service_role, for new tables. This change affects how new tables and views behave in the public schema. In a study of 100 public project histories, 97 of them contained at least one table that the service_role could not read or write without explicit grants. This happens because the service_role is not a superuser. Also, 92 of the studied projects had at least one policy that could never apply because the relevant role lacked the necessary data privilege. For example, a policy might attempt to use a command that the role cannot perform without a specific grant.

The migration to this new model creates risks for teams using migration histories. Replaying a migration history on a preview branch might accidentally enable old default grants that do not exist in production. Developers must explicitly add grant statements to their migrations to avoid broken access. For instance, a serial column’s default calls a sequence, and the new revoke removes sequence usage too. This can cause inserts to fail with a 42501 error if the role lacks permission to use the sequence. Will the community create more effective tools to manage these new grant requirements? Developers use the supabase-grants-lint to check if their project is ready for the change. The tool reads migration files and replays them through a model of grants, default privileges, and policies to check for errors. Using the –since next flag allows developers to enforce requirements for every migration added from that point forward.