Securing Your Serverless Endpoints: A Look at function.do's Architecture

The promise of function.do is one of radical simplicity: Deploy Functions. Get APIs. You write a piece of focused logic, and instantly, it becomes a scalable, secure, and ready-to-use API endpoint. It’s a powerful paradigm that eliminates servers, boilerplate, and infrastructure management.

But with this simplicity comes a critical question for any serious developer: "If I'm not managing the infrastructure, how do I know it's secure?"

It's a fair question, and the answer lies at the core of our design philosophy. At function.do, security isn't an add-on or a feature you configure; it's the foundation upon which the entire platform is built. Let's pull back the curtain and explore the multi-layered security architecture that protects every serverless API you deploy.

The First Line of Defense: Atomic Design

Security begins with your code's architecture. The function.do platform is built around the concept of atomic functions—small, self-contained units of code designed to perform one specific task perfectly.

This isn't just a best practice for code quality; it's a fundamental security principle.

• Reduced Attack Surface: A function that only generates a greeting has an incredibly small attack surface compared to a monolithic application with thousands of lines of code and dozens of routes. If a vulnerability exists, its potential impact is isolated to that single, specific task.
• Clear Auditing: It's far easier to audit and reason about the security of a 15-line function than a sprawling codebase.

By encouraging you to break down complex problems into these simple, single-purpose units, function.do inherently promotes a more secure and resilient system design, much like the philosophy behind microservices, but without the operational overhead.

Layer 1: The Secure API Gateway

No request ever reaches your function's code directly. Every single call to a .do endpoint first passes through our robust, managed API Gateway. This gateway acts as a vigilant bouncer, inspecting and securing every request before it's allowed entry.

Here's what it handles for you automatically:

• TLS/SSL Encryption: All traffic to and from your endpoints is encrypted with HTTPS by default. There are no "ifs" or "buts." Data in transit is always protected.
• Request Validation & Sanitization: The gateway performs initial checks to ensure requests are well-formed, preventing a class of common malformed payload attacks before they can even reach your function's logic.
• DDoS Protection & Rate Limiting: We absorb the brunt of malicious traffic. The gateway provides built-in protection against Distributed Denial of Service (DDoS) attacks and enforces sensible rate limits to prevent abuse, ensuring your function remains available for legitimate users.

Layer 2: The Isolated Execution Sandbox

Once a request has been vetted by the gateway, it's passed on for execution. This is where the magic of Function as a Service (FaaS) provides its most powerful security guarantee: radical isolation.

Each execution of your function runs in its own ephemeral, sandboxed environment.

• No "Noisy Neighbors": A process running for one function has zero visibility or access to another. A spike in traffic or an error in functionA can never impact the performance or state of functionB.
• Stateless by Default: Every invocation is fresh. The environment is created for the request and destroyed immediately after. This prevents data leakage or state corruption between requests, a common source of bugs and security holes in traditional server environments.
• Secure Dependency Management: As our FAQ states, you can bring your own npm dependencies. These are installed securely within the function's isolated container. A compromised package in one atomic function is contained and cannot affect the rest of your system.

This level of isolation is a key differentiator from platforms that only provide the building blocks. We don't just give you a container; we give you a fully managed, secure, and disposable execution context for every single API call.

Layer 3: Composable and Secure Workflows

What about securing access between functions? This is where the power of composable functions truly shines. You can build complex workflows by having one function call another.

function.do facilitates this with a secure-by-default approach. You can use our SDK or a standard HTTP client to have functions communicate. We provide secure mechanisms for managing access tokens and secrets, so you never have to hardcode credentials or expose sensitive keys in your function code. This allows you to build intricate systems from simple, reusable parts, where each part maintains its own security boundary.

The Lifecycle of a Secure Request

Let's tie it all together. Here's what happens when a client calls your function:

1. A request is sent to https://your-name.function.do/getGreeting.
2. The API Gateway intercepts it. It validates the TLS connection, checks for an API key (if you've configured one), and ensures the request isn't part of a malicious traffic pattern.
3. The gateway forwards the validated request payload to the function runtime.
4. A new, isolated sandbox is instantly provisioned for the getGreeting function.
5. Your function's code and its defined dependencies are loaded into the sandbox.
6. The code executes.
7. The sandbox and all its processes are completely destroyed.
8. The return value is sent back through the gateway, which formats the JSON response and sends it to the client.

Simplicity Without Compromise

Our goal at function.do is to provide a platform with zero boilerplate and zero infrastructure to manage so you can focus purely on your logic. This deep, multi-layered security architecture is how we deliver on that promise without compromise.

While other platforms give you the tools to build a secure application, we give you a secure application by default. Stop worrying about TLS certificates, server patching, and firewall rules.

Ready to build? Deploy your first function and get a secure API in seconds.