Meeting canvases · Systems
Software architecture diagrams, drawn live in your design review
A software architecture diagram is a picture of a system’s parts, its users, its applications and data stores and the outside systems it depends on, joined by labelled arrows that show how they talk. In a design review it gives everyone the same picture to question, starting with the system as one box and zooming in, as the C4 model suggests.
Troopa draws it as the review talks on Teams, Zoom or Google Meet. Say “Hi Troopa, draw an architecture diagram of the new checkout”, and each part people name appears in its place, people and apps on the left, services and queues in the middle, data stores and outside systems on the right, with the calls between them as labelled arrows.
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Why architecture diagrams fail in reviews
- One person spends an afternoon dragging boxes around, and the diagram is out of date by the time it is presented.
- The arrows have no labels, or point both ways, so nobody can say what actually calls what.
- One master diagram tries to show everything, and the review argues about the picture instead of the design.
- Two people turn out to have different ideas of how the parts connect, and nobody finds out until the build.
- The review runs for an hour without a decision, and the same questions come back next week.
- Whiteboarding on a video call means one person sharing a drawing tool while everyone else watches them struggle.
How to draw an architecture diagram in a design review with Troopa
Step 1: Open the diagram
Say “Hi Troopa, draw an architecture diagram of the new checkout”. When the meeting is called a design review, Troopa offers one as it starts.
Step 2: Describe it as you would at a whiteboard
“The app calls the API gateway, which passes orders to the orders service.” Each part and each labelled arrow appears as it is said.
Step 3: Correct it as you go
Rename or remove a part or an arrow on the card, or drag one part onto another to draw a call. Or tell Troopa “only the payment service talks to the provider”, and it is redrawn.
Step 4: Ask the room if it is right
Present it before the call ends and check it with the people who own each part, which is where the surprises come out.
Step 5: Put it in the design doc
Download it as SVG or PNG for the design document, or as a PDF. It stays with the meeting’s notes, with the discussion that shaped it in the transcript.
A worked example: reviewing a new checkout
An online retailer’s engineers review the design of a new checkout on Zoom before building it. Nadia, the tech lead, runs the review with Troopa open.
- Nadia“Hi Troopa, draw an architecture diagram of the new checkout.”
- Tom“Customers use the mobile app, which calls the API gateway over HTTPS.”
- Nadia“The gateway passes orders to the orders service. That writes to the orders database and publishes an event to the queue.”
- Ama“And the orders service asks the payment service to take payment, which charges the card through the payment provider.”
- Tom“Does anything else talk to the payment provider directly?”
- Nadia“No. Only the payment service, and that’s the boundary the audit will care about.”
Architecture reviews across industries
Fintech and payments
Reviewing a new payment provider or open banking integration, where the diagram’s boundary decides which systems touch card or account data, and so what falls within the audit.
Healthcare IT
Connecting a booking or patient portal to the records and billing systems: the review asks where personal data crosses from one system to another and which system is the source of truth. Integration only, nothing clinical.
Consultancies and systems integrators
A discovery call where the solution architect sketches the client’s current and target system design while the client’s team corrects it, so the proposal starts from a picture both sides agreed.
Manufacturing
Reviewing how the business systems connect to the plant: planning and execution systems, the machines’ controllers and the networks between them, and where the two are kept apart.
Public sector
A service team showing how its new service fits the legacy systems it must work with, and why it built some parts and bought others, which GOV.UK’s Service Standard asks teams to be able to explain.
E-commerce
The review before peak season: checkout, stock, payments and their outside providers on one picture, with the question of what happens when each one is slow.
A software architecture diagram template for design reviews
Answer one question per diagram, and start with the system as a single box among its users and neighbours before zooming in. Every arrow gets a direction and a label.
Diagram: [the question it answers] Level: [context / container / component] Scope: [what is in and out] Author: [name] Date: [date] Parts Name | Kind (person, app, service, data store, queue, outside system) | Owner [name] | [kind] | [team] Arrows (one row each; label every one) From | To | What it does | How (protocol) | Waits for an answer? [part] | [part] | [verb phrase] | [HTTPS / event] | [yes / no] Boundaries: [system, trust, region] Open questions: [unknowns, marked with “?” rather than guessed]
Questions to ask in the design review
- What problem is this design for, and what is deliberately out of scope?
- Where does data come in, where is it stored, and which of it is sensitive?
- What happens when each dependency is slow or down? Where is the single point of failure?
- Which choices would be hard to reverse, and what alternatives were considered?
- How will it scale, what will it cost to run, and how will we know it is healthy?
- Who owns each part, and does every arrow have a label everyone agrees with?
Questions about architecture diagrams
What should a software architecture diagram include?
The system’s users, its main parts such as applications, services and data stores, the outside systems it depends on, and labelled arrows showing what each part sends or asks of another. Add a title saying what question it answers, a key for its shapes, and the date it was last true.
What is the C4 model?
A way of drawing software architecture at four levels of zoom, created by Simon Brown: context diagrams (the system and its neighbours), containers (its applications and data stores), components (the parts inside one container) and code. Most design reviews need only the first two.Simon Brown, The C4 model for visualising software architecture →
Should we use C4 or UML for architecture diagrams?
C4 is a set of levels and simple boxes and arrows, easy to read for anyone in the review; UML® is a full notation with many diagram types. Many teams draw C4 views for the big picture and a UML sequence diagram where the order of calls matters.
How do you keep architecture diagrams up to date?
Draw fewer of them, each answering a question someone is still asking, and change them in the same piece of work as the system they describe. Retire the ones that no longer answer anything, rather than leaving them to mislead.Microsoft, Azure Well-Architected Framework: design diagrams →
How long should an architecture review take?
Short enough to stay a conversation rather than an audit: hours, not days, as AWS puts it, and often thirty to sixty minutes for one decision. Send the diagram and the question beforehand, and end with a decision and who acts on it.AWS Well-Architected Framework, The review process →
Can AI draw an architecture diagram from a meeting?
Yes. Troopa draws one from what people say during the design review itself, on Microsoft Teams, Zoom or Google Meet, and redraws it when somebody changes it on the card or asks it to. Check it with the people who own each part before relying on it, as you would any diagram.
Sources
- Simon Brown, The C4 model for visualising software architecture
- Microsoft, Azure Well-Architected Framework: design diagrams
- AWS Well-Architected Framework, The review process
Read on 15 October 2026, by the people who make Troopa.
UML® and Unified Modeling Language™ are either registered trademarks or trademarks of Object Management Group, Inc. in the United States and/or other countries.
Try it in your next meeting
Install Troopa on your Mac, Windows PC or Ubuntu computer, join your call on Teams, Zoom or Google Meet as you always do, and ask: “Hi Troopa, draw an architecture diagram of the new checkout.”
14 days free, no card. Then $15 per seat, per month. Cancel any time.