System Design · Mid to Senior
System Design Diagram Pack
Load balancers, caching, DB replication, queues and CDNs, the building blocks, described clearly.
The components you assemble in every design, with when and why to use each.
- Questions
- 360
- Topics
- 20
- Pages
- 280pages
- 360 questions, every one with a model answer
- Component-by-component guide
- Common architectures
- Failure modes
- Selection cheat sheet
Get the System Design Diagram Pack — $9
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What is inside
20 chapters, in the order the interviews tend to ask them:
- Context diagrams: the opening picture
- Container diagrams: services, stores and boundaries
- Component diagrams: inside one service
- Sequence diagrams: making time visible
- Data flow diagrams: following the bytes
- The C4 model as a discipline
- Reading a diagram you did not draw
- Drawing a diagram live in an interview
- Choosing a notation and a tool
- Annotating capacity on a diagram
- Evolving a diagram under questioning
- Trust boundaries and security diagrams
- Deployment and network topology diagrams
- State machine diagrams for lifecycles
- Entity relationship diagrams and data models
- Event flow and queue topology diagrams
- Diagrams as code and in version control
- Legends, colour and visual conventions
- Diagramming anti-patterns and how to fix them
- Living diagrams and documentation practice
How the answers are built
Each chapter opens with the checklist the question is really testing. A few from this pack:
- A context diagram deliberately contains no internal detail, because its job is to be legible to someone outside the team.
- A container is something you can deploy, scale and restart independently; if you cannot, it is a component and belongs a level down.
- A component diagram earns its place when the internal structure decides something, such as where a transaction begins or which failure is survivable.
- A sequence diagram is the right answer the moment the question is about order, not structure.
- A data flow diagram follows data, so the boxes are stores and processes rather than services and dependencies.
- Four levels exist so each diagram has one question, and collapsing them is what produces the unreadable architecture picture.
Questions this pack covers
- What belongs on a system context diagram, and what has to stay out of it?
- How do you decide how large a single system box on a context diagram should be?
- What does a container mean in the C4 model, and how is it different from a component?
- When should something be its own container rather than a module in the same process?
- When should you drill into component level during an interview?
- How do you show a module boundary inside a single service?
- What does a sequence diagram show that a box and arrow diagram cannot?
- When is it acceptable for a sequence diagram to cover only the happy path?
Each one is answered in full in the pack, with the reasoning written out rather than a bullet list.
About this pack
- How many questions?
- 360, spread across 20 topics, written out in full across 280 pages.
- Do the answers just list keywords?
- No. Each answer is written as prose, because that is what you have to reproduce when someone asks you the question.
- How do I get it?
- Pay once and the PDF arrives by email immediately, with a signed download link.
- Can I get it refunded?
- Yes, if it is not what you expected. See the refund policy.
