Stop 08 · Systems & Technical UnderstandingTopics · 5/9

Reading a Technical Architecture Diagram

In short

In design reviews, engineers point at boxes and arrows and talk fast. You don't need to draw these diagrams, but reading one lets you follow along and spot where your requirement actually lands.

Interpreting a diagram showing how a system's components connect — enough fluency to follow a technical discussion and ask informed questions, without needing to design the architecture yourself.

The purple blob holds a torch and looks at a fuse box with wires running to a ceiling fan and a light bulb.

Think of it like this

The wiring of your house

You don't need to be an electrician to read a simple wiring sketch. Boxes are the meter, the fuse box, the fan. Lines show where power flows. If the bedroom fan stops, you can see which switch and which fuse to check.

Watch it happen

Read any architecture diagram in five passes

Users

Boxes

Arrows

Stores

Outside

1/5Find the users first: who starts things? Customers on a phone, staff on a web portal?

The big ideas

What you need to know

Boxes are components

Each box is a piece of software or service. A cylinder usually means a database.

Arrows are calls or data

An arrow shows who talks to whom. Ask if it's a live request or a scheduled data transfer.

Boundaries matter

Dashed boxes often show what's inside your company versus third-party systems you don't control.

Ask good questions

'Where is this rule applied?' or 'What happens if this box is down?' are perfect BA questions.

Save yourself the pain

Common mistakes

Oops

Nodding along and hoping it makes sense later.

Do this instead

Ask the engineer to trace one real user action across the diagram. It makes everything concrete.

Oops

Treating the diagram as current truth.

Do this instead

Ask when it was last updated. Diagrams go stale quickly as systems change.

Your mission

Trace a request

~20 min

Quick check

On a diagram, an arrow goes from 'Order service' to a box outside a dashed line labelled 'Courier partner'. What should a BA think about?

Go deeper

1Read a sample architecture diagram and identify the major components and data flows.
2Practice asking a clarifying question about a diagram instead of nodding along when confused.
3Learn common diagram symbols (databases, services, external systems) well enough to recognize them.