Use Case Guide

Architecture diagram for a proposal: the picture that carries the bid

By the engineer who builds Datadef, from client work on data platforms · Reviewed August 21, 2026

A technical proposal is read by two people who disagree: the sponsor who wants to know what they get, and the in-house engineer asked whether it is credible. The architecture diagram is the only page both of them read, which makes it the part of the document worth the most effort. A proposal diagram argues rather than inventories, it carries the phasing that would otherwise sit in a Gantt chart on another page, and it has to be distributable before the work is sold.

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6 min readFor agencies proposing an architecture before the work is sold

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A proposal diagram is an argument, not an inventory

The failure mode is the complete diagram: every component that will eventually exist, drawn at equal weight, which reads as cost. A proposal diagram should make three claims and be readable in thirty seconds. This is what changes, this is what stays, this is what it costs you in moving parts.

Distinguish bought from built explicitly. A reviewer scoring your bid wants to know how much of the proposed system is a managed service with a support contract and how much is code your agency will write and then leave behind. Drawing the two the same way invites the objection that the client will be dependent on you.

Name real vendors on the nodes. Proposals that say object storage and streaming platform read as templates, and templates lose to bids that say S3 and Kafka, because the second kind can be argued with. Being argued with is how a proposal gets to the second meeting.

Showing phases inside one picture

Most proposals lose the phasing argument by putting it in a Gantt chart on another page. The reviewer sees a large target architecture, prices it as one project, and asks for a discount. Putting the phases into the diagram itself, as zones, changes the conversation to what phase one buys.

One workable grammar: a zone per phase, components inside the zone they arrive in, and edges crossing between zones labelled with what phase two requires from phase one. That makes the dependency argument visible, which is the argument that justifies the sequence you proposed rather than the sequence the client would prefer.

Keep the existing estate outside the phase zones entirely. The client systems are not part of your delivery, and putting them in a phase implies you are touching them.

Two versions, one canvas

Duplicate the target diagram, strip it to the phase one zone, and you have the picture for the executive summary. Both stay in the same project, so a late change to the target does not leave the summary behind.

Distributing it while the deal is still open

Proposal documents get forwarded, and an editable diagram file forwarded into a procurement process is a diagram that comes back modified. A view-only link avoids that: visitors pan and zoom without signing in, no link grants editing, and the editor link from the share dialog only opens the canvas for signed-in invited members.

For the document itself, export the canvas as PNG or JPEG and place the figure inline. The export renders at a viewport you pick, between 600 and 4000 pixels wide and 400 to 4000 tall, defaulting to 1600 by 1000, and it follows the canvas rather than reflowing it, so a wide target architecture wants a wider viewport rather than a taller one before it goes on a page. If the proposal lives on a docs site or a client portal rather than in a file, embed the live diagram instead with a single markdown image line, so a revision during the bid does not require reissuing the document. See live embeds.

Turning public access off is immediate and it stops every embed of that project at the same time, which is worth knowing before you make a bid diagram public on a Friday.

From proposal to project

When the bid is won, the proposal diagram becomes the target architecture the delivery team works against, and the interesting document becomes the difference between it and what actually gets built. Keeping both in the same workspace is what makes that difference visible at the end of phase one.

Give each account its own restricted folder in the team workspace so a bid for one client is not visible to a delivery team working for another. Seats are capped at 5 per team and pending invitations count against the cap, so revoke the invitations of people who left the account before inviting the next consultant.

Once delivery starts, connect the repository your team is building in and let the delivered architecture diagram generate itself. The proposal diagram stays as it was, which is exactly what you want when the retrospective asks what changed.

FAQ

What makes a proposal architecture diagram different from a delivery diagram?

A proposal diagram argues, a delivery diagram documents. It should make three claims quickly: what changes, what stays, and what the client ends up operating. Completeness is a liability at bid stage, because a diagram showing every eventual component reads as cost rather than as capability.

How do I show delivery phases in an architecture diagram?

Draw one zone per phase and place each component in the phase it arrives in, then label the edges crossing between zones with what the later phase needs from the earlier one. That makes the sequencing argument visible in the same picture the reviewer is already reading.

Can I stop a proposal diagram from being edited after it is forwarded?

Yes. Share it as a view-only link rather than a file. Visitors can open, pan, and zoom without signing in, and no shared link grants editing under any setting. Editing requires being invited to the project and signing in.

Should the proposal name specific vendors?

Usually yes. Generic labels like object storage and streaming platform read as a template and cannot be argued with, while named services can be challenged, compared, and priced. A proposal that gets challenged in detail is further along than one that gets filed.

Can a bid diagram be kept away from the rest of the agency?

Put it in a restricted folder inside the team workspace. Only people added to that folder can see the projects inside, while team owners and admins keep access, so a bid for one client is not visible to the team delivering for another.