¶07 - Collaboration

Design under the spotlight.
That's an LLD interview.

Real LLD interviews are observed events. Collaboration lets you practice exactly that dynamic - invite a teammate or mentor, design while they watch, and get live @mention feedback. No refresh. No lag.

Parking Lot Design
D
P
A
3 live
ParkingLot
+ getSpot(): Spot
Level
- spots: List
Deepak
Priya
Arjun
P

@Deepak shouldn't this be composition, not aggregation?

You · EditorMentor · ViewerTeammate · Editor

collaborators (Ultimate)

0

refreshes needed

2

roles - viewer & editor

ws

WebSocket real-time sync

§01 - Featuring

Everything you need for a real design session with others.

Live cursors and presenceStarring everyone
@mention commentsDirector's cut included
Invite by email or linkOpens in seconds
Instant canvas syncUnder 100ms · WebSocket
Role-based accessEnforced server-side
Collaboration dashboardFull activity history

§02 - Three acts

Three ways engineers use collaboration for LLD prep.

Act I  -  Most popular

The Mock Interview

Design under observation. Get feedback in real time.

One person designs on the canvas - timed, with Interview Mode - while a friend or mentor watches via a Viewer link and leaves feedback through @mention comments. Identical to a real interview observation format. The observer can't modify the canvas, but their presence and comments are felt in real time.

Y

You

Designer · Editor

live
M

Mentor

Observer · Viewer

live

Act II  -  Teams

The Design Review

The whole team. The same canvas. No PNG exports.

Share a diagram with your tech team. Everyone joins as a Viewer or Editor. Comments, annotations, and design changes happen in real time - no need to export a PNG and paste it into Slack. Async feedback and live discussion in the same thread. The canvas is the single source of truth.

Y

You

Owner · Editor

live
T

Team

Reviewers · Mixed roles

live

Act III  -  Mentorship

The Guided Session

A senior engineer, same canvas, guiding in real time.

A senior engineer joins as an Editor alongside a junior. They can guide by adding nodes, correcting relationships, and leaving detailed comments - working on exactly the same canvas, together, without friction or lag. No screenshare, no out-of-sync copies.

J

Junior

Learner · Editor

live
S

Senior

Guide · Editor

live

§03 - How it works

Built on WebSockets for zero-latency sync.

1

Create invite

Enter email, pick Editor or Viewer role. Invitation sent immediately.

2

Collaborator accepts

They open the link, authenticate, and join the canvas.

3

Live session

Cursors appear, edits sync in real time via WebSocket.

4

Comment and review

@mention comments appear in all panels instantly.

Frequently asked questions

How many people can collaborate on one diagram?

Pro plans support up to 3 collaborators per diagram. Ultimate supports unlimited collaborators per diagram.

How do I invite someone to collaborate?

Click the Collaborate button in the editor toolbar. Enter their email address and assign a viewer or editor role. They receive an invitation link - the moment they accept, they appear in the live presence stack and their cursor becomes visible on the canvas.

Can I control who can edit vs. who can only view?

Yes - two roles are available per invitation: Editor (can modify nodes and relationships) and Viewer (can view and comment, but not modify the canvas). Role changes take effect instantly without a re-invite.

Do comments stay attached to the diagram?

Yes - comments in the Discussion panel are tied to the diagram session. You can @mention any collaborator and they'll see a badge count on the Comments button in real time.

Is this useful for mock interviews?

Yes - a very common use case is one person designing on the canvas while a friend, mentor, or senior engineer watches live and leaves questions or feedback via @mention comments - simulating a real whiteboard interview with an observer.

What happens if the collaboration connection drops?

The canvas autosaves your work continuously. If a collaborator disconnects, they can rejoin from the same link - their cursor reappears and the canvas state re-syncs immediately.

Can I use collaboration for a team design review?

Yes - invite your whole team (Ultimate plan), share the canvas link, and have everyone annotate via comments simultaneously. It's the same workflow as a Figma review session, but for LLD class diagrams.

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