Features Required:

1. Function Execution: Ability to execute code in response to events or triggers.

2. Scalability: The system should automatically scale based on the incoming workload.

3. Event Sources: Support for various event sources, such as HTTP requests, file uploads, database changes, and more.

4. Isolation: Ensure that functions run in isolated environments to prevent interference between executions.

5. Resource Management: Efficiently allocate resources (CPU, memory) to functions based on their requirements.

6. Logging and Monitoring: Provide logs and monitoring capabilities to track the execution of functions.

7. Security: Implement security measures to prevent unauthorized access and code execution.

8. Versioning: Allow the deployment and management of multiple versions of functions.

9. Environment Variables: Support for setting environment variables for functions.

10. Concurrency Control: Limit the number of concurrent executions of a function.

11. Timeouts: Define maximum execution times for functions to prevent resource hogging.

Design Patterns Involved or Used:

1. Serverless Architecture: Utilize a serverless architecture where infrastructure management is abstracted away.

2. Microservices: Design the system as a collection of microservices, each responsible for a specific function.

3. Observer Pattern: Implement event-driven architecture to handle various event sources.

4. Singleton Pattern: Use singletons for managing shared resources like configuration and authentication.

5. Factory Pattern: Create instances of function environments and executions using factories.

6. Strategy Pattern: Use different strategies for resource allocation and scalability.

7. Command Pattern: Represent requests as objects, allowing for queuing and tracking.

8. Decorator Pattern: Add functionality to functions dynamically, such as logging and security checks.

9. State Pattern: Manage the state of function executions, such as pending, running, or completed.

Code: Detailed Implementation of Classes Based on Each Design Pattern Mentioned Above

// Singleton Pattern
class ConfigurationManager {
    private static ConfigurationManager instance;

    private ConfigurationManager() {
        // Initialize configuration settings
    }

    public static ConfigurationManager getInstance() {
        if (instance == null) {
            instance = new ConfigurationManager();
        }
        return instance;
    }

    public String getConfig(String key) {
        // Retrieve configuration values
    }
}

// Factory Pattern
class FunctionFactory {
    public Function createFunction(String type) {
        // Create and configure function instances
    }
}

// Strategy Pattern
interface ResourceAllocationStrategy {
    void allocateResources(FunctionExecution function);
}

class BasicResourceAllocation implements ResourceAllocationStrategy {
    public void allocateResources(FunctionExecution function) {
        // Allocate basic resources
    }
}

class HighMemoryResourceAllocation implements ResourceAllocationStrategy {
    public void allocateResources(FunctionExecution function) {
        // Allocate additional memory resources
    }
}

// Command Pattern
class RequestCommand {
    private FunctionExecution function;

    public RequestCommand(FunctionExecution function) {
        this.function = function;
    }

    public void execute() {
        // Execute the function
    }
}

// State Pattern
interface FunctionState {
    void handle(FunctionExecution function);
}

class PendingState implements FunctionState {
    public void handle(FunctionExecution function) {
        // Handle pending state
    }
}

class RunningState implements FunctionState {
    public void handle(FunctionExecution function) {
        // Handle running state
    }
}

class CompletedState implements FunctionState {
    public void handle(FunctionExecution function) {
        // Handle completed state
    }
}

This code represents a basic structure for an AWS Lambda-like system, showcasing the utilization of various design patterns for different aspects of the system. However, building a full-fledged system like AWS Lambda would require a more extensive and complex implementation, along with considerations for security, scalability, and event-driven architecture.

[WIP]. Will Add More Code Soon....