1. Intro

Tester here.

Cloud technology makes me dizzy. There are too many concepts, services, and so much lingo. Even though cloud computing has been around for over a decade, it still feels overwhelming.

As a simple person, I decided to approach cloud computing with a systems engineering mindset—stepping back to get a 50,000 ft view of the big picture.

2. What & Why Systems Engineering?

A systems engineering approach breaks down complex systems into manageable pieces. This helps us understand, analyze, and eventually test and exploit them.

Let’s oversimplify the process:

1. Need: Define the problem (use cases & feasibility)
2. Requirements: Identify functional, physical, interface, and constraint requirements
3. Architecture & Design: Develop high-level and low-level blueprints
4. Implementation: Build and configure the solution
5. Integration: Connect the new system with existing ones
6. Verification & Validation: Ensure the system works as expected
7. Deployment & Operations: Maintain, monitor, and scale the solution

Before smart people build cool things, they follow this structured process. Let’s see how this works with a couple of examples.

2.1 Use Case 1: The Individual (Bob’s Cloud Journey)

Imagine Bob wants to access his data from anywhere.

Steps:

1. The DIY Approach:

   • Bob exposes his router to the internet.
     • Simple: Bob → Router → Home Computer
   • He soon gets random connection requests from hackers.

2. The First Fix:

   • Bob adds a firewall and basic username/password protection.
   • System Progression:
     • Enhanced: Bob → Firewall → IdM (Identity Management) → Router → Home Computer

3. Expanding Storage:

• Bob runs out of space and adds an external hard drive.
  • Enhanced+: Bob → Firewall → (IdM) → Router → Home Server (NAS) → Storage

11. Hardware Upgrades:

• After upgrading his CPU, Bob realizes that maintenance costs (RAM, CPU, RAID, UPS, etc.) are spiraling out of control.
  • Enhanced++: Bob → Firewall → (IdM) → Router → Home Server (NAS) → Storage → RAID → UPS → @

The Problem: Even for one person, maintaining an IT setup can quickly become expensive and overly complex.

2.2 Use Case 2: The Business (AtoZ Cyber LLC)

Now imagine a small business: AtoZ Cyber LLC.

Stage 1: A Basic Setup

• AtoZ Cyber LLC sells books and employs remote workers.
• They need secure access to internal systems and a website that runs 24/7.

Scenarios:

• In-Person Workers: IdM → Internal Server
• Remote Workers: IdM → VPN → Firewall → Internal Server
• Customers: Firewall → Website → Data Server

Stage 2: Growth & Complexity

• More customers mean increased traffic and a need for scalability.
• More data means higher storage and redundancy requirements.

New Architecture:

• Customers:
  Load Balancer → Firewall/WAF → Web Servers → Data Server (High Availability Setup) → CDN

• Remote Workers:
  IdM → VPN Gateway → Firewall → Internal Network

Business Pain Points:

• Rising hardware and maintenance costs
• The need for 24/7 availability and scalability
• Increased security risks with more complex architectures

3. Enter the Cloud

Both use cases highlight two major challenges:

• Scalability: Systems shall grow on demand.
• Availability: Systems shall be online 24/7 without downtime.

3.1 How Cloud Solves This?

Cloud computing addresses these issues by outsourcing infrastructure management. Instead of buying, maintaining, and securing physical hardware, businesses leverage cloud providers like AWS, Azure, and GCP.

💡 With just an internet connection, businesses can scale globally—without the headache of managing hardware.

4. Cloud Services Mapping: AWS, Azure, and GCP

5. Cloud Development Framework

Let’s map the structured systems engineering approach to cloud development, incorporating the customer's perspective at each stage.

Cloud Development Requirements Specification

1. General Requirements

1.1 The cloud-based system shall provide scalable infrastructure to support business growth.
1.2 The system shall ensure high availability (99.9% uptime or higher) to meet customer expectations.
1.3 The cloud platform shall support multi-region deployment to enhance performance and redundancy.
1.4 The solution shall integrate with on-premises systems when necessary.

2. Security Requirements

2.1 The system shall enforce Identity and Access Management (IAM) policies to restrict unauthorized access.
2.2 The cloud infrastructure shall comply with industry security standards (e.g., ISO 27001, SOC 2, NIST).
2.3 Data at rest shall be encrypted using AES-256, and data in transit shall be secured with TLS 1.2 or higher.
2.4 The system shall provide DDoS protection and Web Application Firewall (WAF) capabilities.
2.5 Multi-Factor Authentication (MFA) shall be enforced for privileged accounts.

3. Performance & Scalability Requirements

3.1 The cloud infrastructure shall auto-scale to handle peak traffic loads without service degradation.
3.2 The system shall provide low-latency content delivery through a CDN for global users.
3.3 Cloud services shall support serverless computing to optimize cost and resource efficiency.

4. Reliability & Availability Requirements

4.1 The system shall implement disaster recovery mechanisms with an RTO (Recovery Time Objective) ≤ 30 minutes.
4.2 The cloud provider shall offer SLA-backed uptime guarantees for critical services.
4.3 The cloud architecture shall support multi-zone redundancy for fault tolerance.

5. Compliance & Governance Requirements

5.1 The cloud environment shall support audit logging and monitoring to detect security incidents.
5.2 All deployments shall follow Infrastructure-as-Code (IaC) best practices for consistency.
5.3 The system shall enforce least privilege access for all cloud resources.

6. Customer Experience Requirements

6.1 The system shall provide a fast, responsive, and intuitive user interface for customers.
6.2 Authentication and login processes shall be secure yet user-friendly (e.g., SSO & OAuth support).
6.3 Customer support shall be available 24/7 to handle critical issues.

1. Clouds testing Scoping

Learn how to attack clouds

0. Attack Clouds
1. Search for Credentials - Services
2. Search for Credentials - File