Serverless vs BaaS: Which Architecture Fits Your App?

Serverless computing runs your code in response to events without managing servers. AWS Lambda, Vercel Functions, Cloudflare Workers, and Supabase Edge Functions are all serverless platforms.

You write a function, deploy it, and the platform handles scaling, availability, and infrastructure. You pay per invocation rather than for idle servers.

Serverless is ideal for custom business logic: processing webhooks, transforming data, calling third-party APIs, running scheduled jobs, and handling form submissions. It's less ideal for stateful operations, long-running processes, and real-time connections.

Backend as a Service provides pre-built backend capabilities (auth, database, storage) through APIs. Supabase, Firebase, Appwrite, and ShipStack are BaaS platforms.

You don't write backend code for standard operations. User registration? Call an API. Store data? Call an API. Upload a file? Call an API. The platform handles the implementation, scaling, and maintenance.

BaaS is ideal for standard backend operations that every app needs. It's less ideal for highly custom business logic that can't be expressed as CRUD operations.

Code vs. configuration: Serverless requires you to write code for every operation. BaaS provides pre-built operations you configure.

Flexibility vs. speed: Serverless can do anything you can code. BaaS can only do what it supports — but it does it instantly.

Scaling model: Serverless scales per function invocation. BaaS scales per API call to pre-built endpoints.

Maintenance: Serverless requires maintaining function code, dependencies, and deployment pipelines. BaaS requires maintaining configuration and provider credentials.

Cost at scale: Serverless can get expensive with high invocation counts (millions of Lambda calls add up). BaaS pricing is typically more predictable with tier-based models.

Choose serverless when your backend has:

- Custom business logic — Payment processing, complex calculations, data transformations that can't be expressed as simple CRUD. - Third-party integrations — Calling external APIs (Stripe, Twilio, OpenAI) with custom logic around the calls. - Event-driven workflows — Processing webhooks, handling queue messages, running scheduled tasks. - Compute-intensive operations — Image processing, PDF generation, data analysis.

Serverless excels when your backend is primarily custom logic with some standard operations mixed in.

Choose BaaS when your backend is primarily:

- Auth + CRUD + Storage — The vast majority of apps need these three things, and BaaS provides them instantly. - Standard data operations — If your backend is 80% create/read/update/delete, BaaS handles it without writing code. - Multi-platform — BaaS APIs work from web, mobile, desktop, and server environments identically. - Rapid development — When time-to-market matters more than architectural purity.

BaaS excels when your backend is primarily standard operations with some custom logic mixed in.

Most production apps benefit from combining both approaches:

- Use BaaS (ShipStack) for auth, database CRUD, and file storage — the 80% of your backend that's standard. - Use serverless for the 20% that's custom: webhook processing, third-party API calls, complex business logic, scheduled jobs.

This architecture gives you BaaS speed for standard operations and serverless flexibility for custom logic. Your serverless functions can call ShipStack's API for data access, so you don't even need database connection management in your functions.

ShipStack makes this pattern especially clean because it's a REST API. Your serverless functions call the same endpoints as your frontend — no special server-side SDK or connection pooling required.

The practical recommendation: start with BaaS for everything. Add serverless functions only when you encounter a requirement that BaaS can't handle. Most apps never need more than 2-3 custom functions alongside their BaaS backend.