What is complexity for you?

# What Is Complexity for You?

In the ever-evolving landscape of tech interviews, one question seems to loom large: "Tell me about your most complex project." For many candidates, this query can feel like a riddle wrapped in a mystery. What exactly do interviewers mean by "complexity"? As someone who has navigated this question more times than I can count, I find it essential to unpack this notion of complexity and how it varies across contexts.

## Two Dimensions of Complexity

In my experience, complexity can be categorized into two distinct types:

### 1. **Project Management Complexity (PMing)**

This form of complexity revolves around coordination and collaboration. It often involves:

- **Multiple Teams**: The need for various teams to work together, each with its unique expertise and perspective. 
- **Technical Planning**: Opening up silos and ensuring that everyone is on the same page regarding the project's goals and the technical strategies required to achieve them.
- **Understanding Codebases**: Diving deep into existing systems to grasp how different components interact, and identifying the best paths to reach the desired outcomes.

In essence, PMing complexity is about orchestrating various elements to create a cohesive project that meets its objectives. This can be intricate, especially in large organizations where communication barriers can lead to misunderstandings and delays.

### 2. **Technical Complexity**

The second type leans more towards the technical realm and includes challenges such as:

- **Performance Bottlenecks**: Identifying and resolving issues that hinder the system's performance, often requiring creative problem-solving and extensive research.
- **Cost Efficiency**: Finding innovative solutions to ensure that projects remain cost-effective without sacrificing reliability or performance. 
- **Novel Implementations**: Introducing new features or systems that must operate at scale, which often brings its own set of challenges and complexities.

While both types of complexity can overlap—since a project may require both technical prowess and project management skills—differentiating between them can clarify discussions during interviews.

## The Interviewer's Perspective

Despite my attempts to articulate these forms of complexity, I've encountered interviewers who respond with a puzzled look, as if they are struggling to understand where the complexity lies in my examples. This has prompted me to ask them to define what they consider "complex." More often than not, they can't provide a clear answer, which raises an important issue: if an interviewer cannot define what they are measuring, how can they assess your response effectively?

### The Importance of Clarity

In my conversations with other professionals, a recurring theme emerges: **clarity is crucial**. Here are some insights from my peers:

- **Architectural Complexity**: One colleague pointed out that complexity can be better understood through the lens of infrastructure and architecture. For instance, a project that relies on multiple cloud services across different providers, or one composed of tightly coupled microservices, embodies technical complexity. 

- **Process vs. Project Complexity**: Another professional noted that the first type of complexity I described—PMing—may be more about process than the project itself. While managing a project with many moving parts can be complex, the solution ideally should be clean and elegant, minimizing unnecessary complications.

- **Defining Complexity**: A wise approach is to ask, “Complexity in terms of what?” This question can guide the discussion and provide insight into what the interviewer values. For example, a technically simple CRUD application might be complex due to regulatory requirements or organizational challenges, while a technically complex problem may not carry the same weight in a larger context.

## Conclusion: Navigating Complexity in Interviews

As someone currently working with five million daily active users and managing scalable, fault-tolerant systems, I often reflect on how to convey the intricacies of my work during interviews. Here are a few takeaways:

- **Clarify Expectations**: Don’t hesitate to ask interviewers what they mean by complexity. This can lead to a more fruitful discussion.

- **Prepare Diverse Examples**: Be ready to discuss both project management and technical complexities, as well as how they intertwine.

- **Emphasize Results**: Highlight how you navigated complexity to achieve positive outcomes, whether through innovative solutions or effective collaboration.

Ultimately, complexity is a nuanced concept that can significantly impact how you present your experience in interviews. By understanding its dimensions and preparing to articulate them, you'll be better equipped to tackle this common yet perplexing question.