HLD vs LLD distinction - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to identify the main focus of HLD.

HLD

HLD primarily focuses on [1] of the system.

Drag options to blanks, or click blank then click option'

Adetailed coding

Boverall architecture

Cunit testing

Ddatabase queries

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing HLD with detailed coding tasks.

Thinking HLD includes unit test details.

HLD (High-Level Design) focuses on the overall architecture of the system, showing components and their interactions.

2fill in blank

medium

Complete the code to identify the main focus of LLD.

HLD

LLD mainly deals with [1] of system components.

Drag options to blanks, or click blank then click option'

Adetailed design

Bhigh-level architecture

Cuser interface layout

Dnetwork protocols

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing LLD with overall system architecture.

Assuming LLD covers user interface design only.

LLD (Low-Level Design) focuses on detailed design of components, including algorithms and data structures.

3fill in blank

hard

Fix the error in the statement about HLD and LLD.

HLD

HLD does NOT include [1] details like class methods and variables.

Drag options to blanks, or click blank then click option'

Anetwork

Bonly high-level

Cdetailed

Ddatabase

Attempts:

3 left

💡 Hint

Common Mistakes

Thinking HLD covers detailed class design.

Confusing detailed design with architecture.

HLD does not include detailed design like class methods; that belongs to LLD.

4fill in blank

hard

Fill both blanks to complete the comparison between HLD and LLD.

HLD

HLD shows [1] while LLD shows [2].

Drag options to blanks, or click blank then click option'

Asystem components

Bcode structure

Cuser interactions

Dhardware details

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing user interactions with design levels.

Confusing hardware details with software design.

HLD shows system components and their relationships, while LLD shows the code structure inside those components.

5fill in blank

hard

Fill all three blanks to complete the design process steps.

HLD

First, create [1] to outline the system. Then, develop [2] for modules. Finally, write [3] to implement features.

Drag options to blanks, or click blank then click option'

AHLD

BLLD

Ccode

Dtest cases

Attempts:

3 left

💡 Hint

Common Mistakes

Reversing the order of design steps.

Confusing test cases with design phases.

The design process starts with HLD to outline the system, then LLD for module details, and finally code implementation.

Practice

1. Which of the following best describes the purpose of a High-Level Design (HLD)?

easy

A. It provides detailed code-level logic for each module.

B. It shows the overall system architecture and main components.

C. It lists all the database table schemas.

D. It contains the exact API request and response formats.

Solution

1. Step 1: Understand HLD focus

   HLD focuses on the big picture, showing main parts and their relationships.

2. Step 2: Compare options

   The option that shows the overall system architecture and main components describes HLD.

3. Final Answer:

   It shows the overall system architecture and main components. -> Option B

4. Quick Check:

   HLD = Big Picture [OK]

Hint: HLD = big picture, LLD = details [OK]

Common Mistakes:

• Confusing HLD with detailed design
• Thinking HLD includes code logic
• Mixing database schema details with HLD

2. Which statement correctly differentiates Low-Level Design (LLD) from High-Level Design (HLD)?

easy

A. LLD is used for planning; HLD is used for coding.

B. LLD shows system modules and their interactions; HLD shows code details.

C. LLD explains detailed logic and data structures; HLD shows system components.

D. LLD focuses on user interface design; HLD focuses on database design.

Solution

1. Step 1: Identify LLD and HLD roles

   LLD explains detailed logic and data structures, while HLD shows system components and their relationships.

2. Step 2: Evaluate options

   The option stating 'LLD explains detailed logic and data structures; HLD shows system components.' correctly differentiates them, matching their definitions.

3. Final Answer:

   LLD explains detailed logic and data structures; HLD shows system components. -> Option C

4. Quick Check:

   LLD = Details, HLD = Components [OK]

Hint: LLD = details, HLD = overview [OK]

Common Mistakes:

• Reversing roles of HLD and LLD
• Confusing planning and coding phases
• Mixing UI and database focus incorrectly

3. Given a system design process, which output is expected from the Low-Level Design (LLD) phase?

medium

A. A diagram showing major system components and their interactions.

B. A high-level flowchart of system data flow.

C. A list of user requirements and business goals.

D. Detailed class diagrams and sequence diagrams for modules.

Solution

1. Step 1: Recall LLD deliverables

   LLD includes detailed design artifacts like class diagrams and sequence diagrams showing module internals.

2. Step 2: Match options to LLD

   Detailed class diagrams and sequence diagrams for modules match the detailed diagrams expected in LLD; others describe higher-level or requirement outputs.

3. Final Answer:

   Detailed class diagrams and sequence diagrams for modules. -> Option D

4. Quick Check:

   LLD = Detailed diagrams [OK]

Hint: LLD = detailed diagrams like class and sequence [OK]

Common Mistakes:

• Choosing high-level diagrams for LLD
• Confusing requirements with design outputs
• Selecting flowcharts meant for HLD

4. A team mistakenly uses High-Level Design (HLD) diagrams to write detailed code logic. What is the main issue with this approach?

medium

A. HLD lacks the detailed information needed for coding.

B. HLD contains too much detail, causing confusion.

C. HLD diagrams are only for database design.

D. HLD is only used after coding is complete.

Solution

1. Step 1: Understand HLD purpose

   HLD provides a broad overview, not detailed logic needed for coding.

2. Step 2: Identify problem

   Using HLD for coding misses necessary details, causing incomplete or incorrect code.

3. Final Answer:

   HLD lacks the detailed information needed for coding. -> Option A

4. Quick Check:

   HLD = overview, not detailed code [OK]

Hint: HLD is overview, not detailed code [OK]

Common Mistakes:

• Thinking HLD has too much detail
• Believing HLD is only for database
• Assuming HLD is post-coding

5. You are designing a new online shopping system. Which design phase should you use to decide the main system components and their interactions, and which phase to define the detailed logic of the payment module?

hard

A. Use HLD for main components and LLD for payment module details.

B. Use LLD for main components and HLD for payment module details.

C. Use HLD for both main components and payment module details.

D. Use LLD for both main components and payment module details.

Solution

1. Step 1: Identify phase for main components

   Main system components and their interactions are defined in High-Level Design (HLD).

2. Step 2: Identify phase for detailed module logic

   Detailed logic, like payment module internals, is defined in Low-Level Design (LLD).

3. Final Answer:

   Use HLD for main components and LLD for payment module details. -> Option A

4. Quick Check:

   HLD = components, LLD = details [OK]

Hint: HLD = components, LLD = detailed logic [OK]

Common Mistakes:

• Swapping HLD and LLD roles
• Using one phase for all design
• Ignoring detailed design for modules