Non-functional Application Requirements: An Introduction

When we think about building applications, most of us start with the obvious—functional requirements. We focus on what the app should do—the features, the user flows, and the outputs. But as your application grows, you quickly realize that the real challenges often lie in what the app must be—secure, fast, always available, and easy to maintain.

That’s where non-functional requirements come in.

Inspired by Dr. Werner Vogels' insightful keynote at AWS re:Invent 2023, this series explores these often-overlooked aspects of application development. Non-functional requirements (NFRs) are not just technical jargon—they’re the pillars that determine whether your application will thrive or fall apart as it scales. Whether you’re building a startup MVP or managing a massive enterprise app, you’ll face these challenges.

Why You Should Care About Non-Functional Requirements

Imagine launching an application that looks great and works well—until your first 10,000 users arrive, and it slows to a crawl. Or perhaps you’ve built an app that processes sensitive data but hasn’t accounted for the latest security protocols, leaving you vulnerable to a data breach. What about the cost of maintaining that app over time? How will you handle updates, compliance audits, and infrastructure scaling?

This series isn’t about abstract theory—it’s about solving real problems. Each post will focus on a different non-functional requirement, breaking it down with real-world examples, hands-on tutorials, and insights into AWS services that can make implementation smoother. Whether you're a developer, cloud architect, or DevOps engineer, this guide is for you.

What’s Ahead?

We’ll cover the nine key non-functional requirements that every modern application needs to address:

1. Security
2. Compliance
3. Accessibility
4. Performance
5. Availability
6. Scalability
7. Maintainability
8. Cost
9. Sustainability

The first three are non-negotiable. They’re critical to protecting your users, data, and business. The remaining six require thoughtful trade-offs—you can’t have it all without some compromises, so we’ll dive into how to make those tough decisions.

Breaking It Down: What You’ll Learn

In this series, we’ll answer the 5Ws (What, Why, When, Where, Who) for each requirement, but we’ll also take things a step further. We’ll approach each topic from different angles to ensure you get a well-rounded understanding of how these principles impact your applications, both technically and strategically.

• Hands-On Tutorials: You'll get practical guides, walking you through the setup and optimization of key AWS services like AWS Shield, AWS Cognito, EC2 Auto Scaling, and more.
• Real-World Case Studies: We’ll learn from the successes and failures of companies that have tackled these challenges head-on, especially in high-stakes environments like e-commerce, healthcare, and startups.
• Pitfalls & Lessons Learned: Don’t fall into the common traps—discover what to avoid before it becomes a costly mistake.
• Expert Insights: We’ll feature interviews with industry experts who live and breathe security, compliance, and cloud architecture.
• Cost-Benefit Analysis: Balancing trade-offs between performance, scalability, and cost efficiency will be a recurring theme.

A Quick Look at What’s Coming

Security: The Bedrock of Trust

In today’s hyper-connected world, your app’s security is always under scrutiny. We’ll dive into encryption, authentication, and threat protection using AWS services like Cognito and AWS Shield—plus a few non-AWS tools like Nessus for vulnerability scanning. Expect step-by-step guidance, code examples, and real-world scenarios.

Compliance: Navigating the Regulatory Maze

Staying compliant with global regulations like GDPR, HIPAA, and SOC 2 is critical to keeping your business afloat. We’ll break down how AWS services like AWS Config and AWS Artifact help you meet these ever-evolving requirements, backed by a case study on how a healthcare company successfully implemented compliance from day one.

Accessibility: Designing for Everyone

Accessibility is about more than ticking boxes—it’s about ensuring your app works for every user, regardless of their abilities. We’ll separate myth from fact, showing you how to use AWS Amplify, React’s accessibility features, and tools like axe DevTools to make your app more inclusive.

Performance: Faster, Smoother, Better

Performance optimization isn’t just about reducing latency; it’s about providing a seamless user experience, even under load. We’ll explore AWS CloudFront for fast content delivery, and look at how serverless can be a game-changer for scaling apps efficiently.

Availability: Your App, Always On

How do you keep your app running, even during server failures or spikes in traffic? We’ll tackle high availability with multi-region architectures and services like Elastic Load Balancing (ELB) and Route 53, ensuring your app has zero downtime, no matter what.

Scalability: Ready to Grow?

As your user base grows, your app needs to grow with it. We’ll break down horizontal vs. vertical scaling, using AWS EC2 Auto Scaling, EKS, and more. Plus, we’ll discuss how to manage costs while scaling efficiently—a key consideration for any growing business.

Maintainability: Preparing for the Long Haul

Building maintainable systems saves you time and headaches in the long run. We’ll share best practices for code organization, testing, and CI/CD using AWS services like AWS CodeBuild, CodeDeploy, and CloudWatch. You’ll learn how to keep your app running smoothly, even as it evolves.

Cost: Optimizing for Efficiency

Cost isn’t just about cutting expenses; it’s about balancing performance, availability, and scalability in the most efficient way. We’ll explore AWS tools like Cost Explorer, AWS Budgets, and Trusted Advisor, along with strategies for minimizing costs without compromising quality.

Sustainability: Building Green Applications

Cloud sustainability is becoming increasingly important. In this post, we’ll explore how to use AWS Lambda and DynamoDB to build energy-efficient, cost-effective applications while reducing your app’s carbon footprint. Plus, we’ll feature insights from experts who are leading the charge in sustainable architecture.

Why This Series Matters

In an era where applications must be fast, scalable, and secure—all while managing costs and sustainability—the importance of non-functional requirements cannot be overstated. These are the elements that ensure your application doesn’t just survive, but thrives in a competitive, rapidly evolving tech landscape.

Whether you're building your first MVP or managing a complex cloud infrastructure for millions of users, this series will equip you with the tools, strategies, and insights you need to build more resilient, reliable, and efficient applications.

Let’s dive in together.

Cover Image: AWS re:Invent 2023 - Keynote with Dr. Werner Vogels