The Future of Diagramming

1. The Evolution of the Diagram - From the Napkin to the Cloud

The story of diagramming tools starts in the same place every good story starts: the napkin. Picture it—engineers scribbling on diner napkins, sketching out designs for machines that could change the world. It was simple. It was messy.

Fast forward a few decades, and we find ourselves in an era of software suites—Microsoft 365, PowerPoint, Visio. Diagrams got an upgrade, and so did their users. Engineers traded napkins for clean, scalable digital lines. There was only one problem: complexity. The tools got better, but also more rigid. Sharing became an exercise in exporting and emailing. Editing someone else’s diagram meant either breaking something or creating a Frankenstein’s monster of half-baked flowcharts.

Then came Mermaid.js, a tool that gave the power back to the users by letting them create diagrams directly from code. No fancy drag-and-drop UI. No license key to share. Just markdown-like syntax and a terminal window. The beauty of simplicity—like MS Paint, but for software engineers.

2. Why Simplicity is the Best Policy (Until It Isn't)

Enter Tesla. They love their diagrams—really, they need them. The job of leading a team of engineers means endless system diagrams, architecture blueprints, and workflow representations. You'd think a team of some of the smartest minds in the world would have the best tools. Well, kind of. They have Microsoft Word and PowerPoint. Yup. The kind of stuff your grandmother uses to make her holiday letter look nice.

The struggle with these tools, according to a senior Tesla engineer that I spoke to, is twofold: time and sharing. PowerPoint is great until you need someone else to edit your boxes and arrows. So what do engineers at Tesla do? They use Mermaid.js. It's free, it's text-based, and—importantly—it's straightforward.

But simplicity has its own limits. When collaboration becomes the priority, text-based tools need to evolve. Tesla's team has seen how real-time collaboration is lacking in their current suite. Sure, they love Mermaid for personal use, but when you want to brainstorm with 20 other engineers, the tools just aren't enough. Simplicity must find a balance with functionality.

3. The Dream Diagramming Tool

Let's dream for a minute—you’re an engineer who wants to diagram the architecture of a new autonomous feature for Tesla. Imagine you open your IDE, type a few lines of code, and boom—a fully interactive diagram appears on the right side of your screen. But it doesn’t stop there. Your team is watching, in real time, adding notes, changing the logic, and the diagram updates instantly—no screenshots, no exports, no PDFs.

This is the vision for the future of tools like Mermaid—simple syntax with advanced features that allow for live editing and generative AI assistance. The Tesla engineers hinted at this vision: a combination of integration, real-time collaboration, and AI.

4. Generative AI - The Future, or Another Fancy Toy?

One of the fascinating conversations around diagramming tools is the rise of Generative AI. Imagine typing: "Show me a system architecture for autonomous driving," and watching as the diagram unfolds, node by node. Tools like Lucidchart are already hopping on this trend, with integrated AI that can generate diagrams based on prompts.

The engineers at Tesla find this appealing, but they’re also skeptical. AI-generated diagrams sound great, but they lack context. It’s like having a really smart intern who knows everything but understands nothing about your project. Without proper integration into the workflows—without tying the diagrams to actual code and data—these tools remain a shiny novelty rather than a real solution.

5. Budget, Bureaucracy, and the Reality of Tool Adoption

All this talk of better tools comes down to one thing: budget. Tesla's engineering team, like many others, has to justify every new tool they want to bring in. It’s not just about "Do we need this?" It’s also "Will the Director sign off on this purchase?"

Right now, Tesla's engineers use the free version of Mermaid because it gets the job done. But with increased needs for collaboration and integration, the potential for adopting the professional version is there. The sticking point? Price vs. value. If the price is right and the features match their needs, the adoption could easily happen—but the engineers need to see the value beyond what they already have for free.

While Mermaid.js is a popular tool for generating diagrams and charts from markdown-like syntax, it faces competition from other tools like PlantUML, Graphviz, and Lucidchart. PlantUML offers robust support for UML diagrams and is favored in software architecture documentation, but it has a steeper learning curve compared to Mermaid. Graphviz is powerful for graph visualization but requires more technical setup and lacks the user-friendly syntax that makes Mermaid appealing. On the other hand, tools like Lucidchart provide a polished, drag-and-drop interface with extensive collaboration features, but they come with subscription fees that may not fit every team's budget. Mermaid.js strikes a balance by offering simplicity, easy integration, and a free tier, though some advanced collaboration and export features are locked behind the professional version. The decision for Tesla’s engineers ultimately hinges on whether these premium features justify the investment or if sticking to the free tool remains the better option.

To help engineers and investors make an informed decision, the table below provides a detailed comparison of Mermaid.js with its main competitors—PlantUML, Graphviz, and Lucidchart. Each tool brings unique strengths and challenges, with varying levels of usability, scalability, integration, and pricing models. The goal of this comparison is to highlight not just the technical capabilities of these tools but also their potential value for enterprise use, collaboration, and customization. By evaluating these metrics, decision-makers can assess which tool best fits their workflow, budget, and long-term needs.

In the world of diagramming, Mermaid.js represents a shift back to simplicity—a move towards tools that don’t try to do everything, but instead do one thing well. The challenge now is evolving that simplicity without losing it, integrating collaboration and AI without making the tool another bloated software suite.

Tesla's engineers want their diagrams to be: easy, accessible, and open to everyone. They also want their diagrams to power their next breakthrough—whether it's autonomous vehicles, AI integration, or something we can’t even imagine yet. The future of diagramming isn’t just about better features—it's about keeping the spirit of the napkin alive in a digital world.