Beyond FaaS: Building Stateful, Agentic Workflows with Functions.do

The rise of Function-as-a-Service (FaaS) platforms like AWS Lambda and Google Cloud Functions revolutionized how we think about backend development. They promised a world free from server management, where we could deploy small, independent units of code that scale on demand. For simple, stateless tasks, FaaS is a powerful tool.

But what happens when your business logic isn't simple?

Real-world applications are rarely a single, isolated function. They are complex processes: multi-step user onboarding, dynamic lead scoring, financial transaction processing. Trying to build these stateful, orchestrated systems on top of inherently stateless FaaS platforms often leads to what's known as "orchestration hell"—a tangled web of queues, state machines defined in YAML, and complex boilerplate code just to pass data from one step to the next.

This is where the paradigm needs to shift from simple function execution to holistic business logic orchestration. This is where Functions.do comes in, moving you beyond FaaS and into the world of agentic workflows.

The Bottleneck of Traditional FaaS

While FaaS excels at event-driven, single-responsibility compute, its limitations become clear when building end-to-end business services:

• Stateless by Nature: Each function invocation is isolated. Persisting state between steps requires you to provision, manage, and integrate an external database or cache, adding operational overhead.
• Complex Orchestration: Manually wiring functions together with message queues or event buses is brittle and hard to debug. Platforms like AWS Step Functions help, but they often move the logic out of your code and into complex JSON or YAML configurations.
• Boilerplate Overload: Every function needs its own code for input validation, error handling, retries, and logging. This repetitive code bloats your services and introduces opportunities for error.

These challenges mean developers spend less time on writing valuable business logic and more time wrestling with infrastructure and plumbing. It's time for a higher level of abstraction.

Enter Agentic Workflows: The Functions.do Philosophy

Functions.do re-imagines function execution not as isolated events, but as a series of intelligent "agents" that work together to complete a business goal. An agentic workflow is a sequence of typesafe functions that operate as a single, stateful, and reliable software service.

Our platform is built on the principle of Business-as-Code. Your business processes shouldn't be fragmented across serverless functions, configuration files, and external state managers. They should live as clean, composable, and testable code.

With Functions.do, you define your logic, and our platform handles the rest:

• State Management: State is automatically managed and passed between functions in a workflow, making multi-step processes trivial to build.
• Orchestration: Chaining functions together is as simple as composing them in code. The platform guarantees execution order.
• Reliability: Built-in error handling and retries between steps ensure your workflows are resilient and can recover from transient failures.

The Power of Typesafety: Building with Confidence

One of the cornerstones of Functions.do is its first-class support for typesafe functions. By leveraging TypeScript interfaces (or other type systems), we build a unbreakable contract for your data as it moves through a workflow.

import { Function } from 'functions.do';

// Define the precise input type for your function
interface Lead {
  companySize: number;
  industry: string;
  hasBudget: boolean;
}

// Create a function agent that understands this type
const scoreLead = Function<Lead>('score-lead-v1');

// Execute the function with typesafe inputs.
// The platform automatically validates the input against the Lead interface.
const { score, reason } = await scoreLead({
  companySize: 250,
  industry: 'SaaS',
  hasBudget: true,
});

console.log(`Lead Score: ${score}/100 - ${reason}`);

What does this mean for you?

1. Eliminate Runtime Errors: Bad data is caught before it ever runs, not when a customer is waiting.
2. Enhance Developer Productivity: Clear, self-documenting contracts and editor autocomplete make building and maintaining complex workflows faster and more intuitive.
3. Guarantee Data Integrity: Ensure the data passed between functions is always in the shape you expect, making your workflows predictable and robust.

From Individual Functions to Complete Workflows

Let's expand our lead scoring example. A real-world process might involve several steps. With Functions.do, you define each step as a simple, focused function and compose them into a powerful workflow.

1. enrichLead Function: Takes a lead's email, uses a third-party API to find company size and industry.
2. scoreLead Function: Takes the enriched lead data and applies business rules to generate a score.
3. routeLead Function: If the score is high, it sends a notification to the enterprise sales Slack channel; otherwise, it adds the lead to a nurturing sequence in a CRM.

On a traditional FaaS platform, you'd be managing queues, handling API keys, and writing intricate error logic for each step. With Functions.do, you simply define the functions and let the platform orchestrate the agentic workflow, managing state and ensuring reliability from start to finish. This code-driven approach keeps your focus where it belongs: on the business logic itself.

Start Building Smarter, Not Harder

Stop building fragmented applications with boilerplate glue code. It's time to elevate your functions into reliable, stateful, and intelligent business services. Functions.do provides the managed, typesafe framework to turn entire business processes into software, abstracting away the underlying complexity.

You write the code that delivers value. We'll handle the rest.

Ready to move beyond FaaS? Explore Functions.do and deploy your first agentic workflow in minutes.