Doc-like surface for writing (notes, meeting minutes, etc.)
Coda starts as a doc, like a Google Doc, so you can write long-form memos, planning documents, or other text-based content, and store that alongside your data.
This is the core features of Asana.
Coda accomplishes this with database tables that can easily hold any type of data - task, project, resource, team, etc.
This is a specific Asana feature
You can do this in Coda by customizing a table - adding a 'sub-task' column, for instance, or even using Lookups to connect a task and a sub-task table together.
Free in Coda - just a matter of adding another column to a table. It takes one second
This requires an upgrade in Asana.
Collaborative surface (editing in real-time)
Customized attributes (dates, checklists, select-lists, and more)
Both products have richly formattable data types.
Mobile (iOS, Android)
Both products support mobile editing.
Neither product has a native desktop app.
Commenting / at-mentioning
Both products support hitting "@" and commenting at or notifying your colleagues.
Automations / workflow (i.e. send email update on regular cadence
Both apps support automations. In Asana it is a paid feature; in Coda the feature has a threshold on the free tier.
Buttons for app-like functionality
Asana has built-in buttons in its app, but does not allow users to customize buttons, for instance, click a button which automatically sends an email to a particular set of stakeholders.
Automations to schedule triggered updates