Creating sequence diagrams using mermaidjs to map out your user journey

I want to talk about an effective product planning process I’ve been following recently.

Why to do user journey thinking?

In your product, single most important thing is to put your users first. Nothing matters other than how your users perceive your product. “Users” is a very general and broad definition and often used without much nuance of different user personas. Anybody who interacts with your product is your user, including you as “admin” or “owner”. There are many other user personas you may need to consider when designing a feature. It’s also important to think maturity of your users adoption of your product. A user who is new to your overall product may take your new feature in a different way than a power user. Similarly, your small biz client’s users may need different things than your enterprise client.

User journeys can easily highlight differences between these users and how they interact with your product or each other. Your feature may require a tech lead to configure things first in your product, then tell their editors to do other things while editors may need to work with their development team to accomplish other goals. So a simple looking feature may require couple different team members to collaborate and communicate.

Sequence Diagrams

Sequence diagram is a type of diagram that does great job telling 2 things:

  • How many participants in a journey
  • The order of things between which participants happen.

And example to this would be, order a food at a restaurant.

Participants:

  • Guest
  • Host
  • Waiter
  • Kitchen

And maybe steps would be:

  • Guest asks Host can I have a table for 2?
  • Host shows and sits the Guests to a table.
  • Waiter comes to the table and asks for order from Guests.
  • Guests places their order.
  • Waiter tells Kitchen about the order
  • Kitchen prepares the order
  • Kitchen tells Waiter that order is ready.
  • Waiter brings food to the table to the Guests

A journey like this can be visualized in a sequence diagram like this:

sequenceDiagram

Guests ->> Host: Can I have a table for 2?
Host ->> Guests: Shows and sits the Guests to a table.
Waiter ->> Geusts: Comes to the table and asks for order.
Guests ->> Waiter: Places their order.
Waiter ->> Kitcken: Tells about the order
Kitchen ->> Kitchen: Prepares the order
Kitchen ->> Waiter: Order is ready.
Waiter ->> Guests: Brings food to the table.

As you see, if we were to design a food ordering feature, we may want to visualize traditional way of ordering food and also visualize our better food ordering experience with our new product feature.

How about user stories?

User stories are key when developing a product. Written user stories are best to summarize a capability, a feature or a user goal. A traditional story would look like:

As a < persona >, I want to < action >, so that I can get < benefit>

User stories written in this traditional sense brings clear, structured, short and written form to your product features. They are essential when the engineering team is planning their implementation in project management tools. Often a user story is planned as a story and engineering team can break it down to sub-tasks about the implementation steps. If user story is describing a bigger goal, it can be planned as an epic and sub stories and tasks can be planned under it.

Let’s roll back to our user journey mapping with sequence diagrams. As you see here, this process does not replace but complements user stories. It makes sense to make the user journey mapping practice before finalizing user stories when planning a product.

Using Mermaid.js for quick Diagramming Tool

Mermaid is an open source software that draws different types of diagrams using simple structured text. One of the diagram types mermaid support is sequence diagrams.

Mermaid draws a sequence diagram using a text formatted like this:

sequenceDiagram

Fatih ->> John: Hi, how are you?
John -->> Fatih: Thanks, I'm good.
John -->> Fatih: How are you?
Fatih ->> John: All good, thanks.

Renders to a nice sequence diagram:

Mermaid Tooling

I’ve covered how to edit and manage mermaid diagrams in your favorite tools in a past article.

You can also alternatively create similar diagrams in free-form mode with excalidraw which I also like. I’ve talked about excalidraw in my previous posts. It will give you way more control to make your diagrams look exactly like you want but obviously it will take much more time to create one compared to mermaid.js diagrams.

Editing and previewing Mermaid diagrams on your docs (markdown, github, notion, confluence)

Mermaid.js is one of my recent favorite tools I’ve added to my toolbox. Mermaid.js is an open-source diagramming tool that converts plain structured text and renders diagrams as SVG or PNG images. You can use the following tools to render and save mermaid diagrams on your documents but there are better ways to create, edit and maintain your mermaid diagrams in your favorite documentation tools. Because of its popularity, a lot of documentation tool supports the mermaid either out of the box or with add-ons.

Mermaid Live Editor

Let’s start with the obvious option. Mermaid.js has an online editor that is free to use and does not require anything. You can quickly start creating diagrams, and share or embed them in your favorite places.

Try: https://mermaid.live

Markdown editors mermaid support

I personally use Visual Studio Code as my markdown editor and I use the Markdown Enhanced Preview extension to preview additional markdown features that include mermaid syntax to be rendered as diagrams.

https://marketplace.visualstudio.com/items?itemName=shd101wyy.markdown-preview-enhanced

I’ve seen most of the text editors that have markdown support to have mermaid support included by default or with add-ons/extensions.

Documentation tools mermaid support

Most tools work with markdown or support markdown features, recognize mermaid.js, and provide out-of-the-box mermaid diagrams support.

Github.com markdown mermaid support

Github started to support mermaid diagrams rendered instead of code blocks if the code block is marked as mermaid syntax.

It works out of the box and when a markdown file is rendered in the preview mode in your repo, it will show the diagram as SVG rendering inline instead of the code block.

Confluence mermaid Plugin

There is a free confluence add-on that adds a page macro that you can insert a mermaid diagram by adding the source diagram text once you insert it to the page, it renders it as an SVG image. It can be easily edited on the page so there is no need to render, export, and insert as an image manually.

https://marketplace.atlassian.com/apps/1222792/mermaid-integration-for-confluence?tab=overview&hosting=cloud

Notion mermaid support

Any code block that is selected as mermaid syntax, gets a mermaid diagram rendered in the code block. It has diagram size limited to the code block width which makes it hard to see large diagrams, but it does render small-size diagrams or things like pie charts powered by mermaid syntax well.