What are the theoretical limits of building serverless apps vs hosting the backend on a server?
Serverless architecture and traditional server-based architecture each have their own advantages and limitations. Understanding these differences can help you make informed decisions when choosing an architecture for your application. Below are some of the theoretical limits and trade-offs associated with both approaches:

**Serverless Architecture:**

- Scalability: Serverless architecture provides automatic scalability, meaning that the platform can handle increased workloads without manual intervention. This makes it well-suited for handling variable or unpredictable workloads.
- Cost: Serverless platforms typically use a pay-as-you-go pricing model, so you only pay for the actual execution time and resources used. This can be cost-effective for workloads with sporadic or variable usage patterns.
- Simplified Operations: Serverless architecture abstracts away infrastructure management, allowing developers to focus on writing code. There is no need to worry about server provisioning, maintenance, or scaling.
- Latency: Serverless functions may experience higher latency, especially if they are "cold-started" (i.e., when a new instance is created after a period of inactivity). This can impact performance-sensitive applications.
Execution Time Limits: Serverless platforms impose execution time limits on functions, which means that long-running tasks may not be suitable for serverless architecture.
- Vendor Lock-in: Serverless architecture relies on cloud providers' platforms, which can lead to vendor lock-in and challenges in porting applications to other platforms.

**Traditional Server-Based Architecture:**

- Control and Flexibility: A traditional server-based architecture gives you more control over the infrastructure and its configuration, allowing for greater customization and optimization.
- Predictable Latency: Server-based architecture provides more predictable latency compared to serverless architecture, as there are no cold starts.
- Long-Running Tasks: Server-based architecture allows you to run long-duration tasks without the constraints imposed by serverless platforms.
- Cost: The cost of running a server-based architecture can be more predictable, as it is usually based on fixed server resource allocation. However, this can also lead to underutilized resources if the workload is variable.
- Maintenance and Operations: With a server-based architecture, you are responsible for provisioning, maintaining, and scaling the infrastructure. This can increase operational overhead.

Ultimately, the choice between serverless and server-based architecture depends on the specific requirements and constraints of your application. Some applications may benefit from a hybrid approach that combines elements of both architectures.