Monolith vs microservices comparison - Practice Questions

Challenge - 5 Problems

🧠 Conceptual

intermediate

Key difference in deployment between monolith and microservices

Which statement best describes the deployment difference between a monolithic application and a microservices architecture?

A Monoliths deploy all features as a single unit; microservices deploy each service independently.

B Monoliths deploy services independently; microservices deploy all features as one unit.

C Both monoliths and microservices deploy all features as a single unit.

D Both monoliths and microservices deploy services independently.

💡 Hint

Think about how updates affect the whole system in each architecture.

Monolithic applications bundle all features into one deployable unit, while microservices allow independent deployment of each service.

❓ scaling

intermediate

Scaling approach difference between monolith and microservices

How does scaling differ between monolithic and microservices architectures?

A Monoliths scale individual services; microservices scale entire application.

B Both scale individual services independently.

C Monoliths scale entire application; microservices scale individual services as needed.

D Both scale entire application as a single unit.

💡 Hint

Consider resource usage when only one feature needs more capacity.

Monoliths require scaling the whole app even if only one part needs it; microservices allow scaling only the needed services.

❓ tradeoff

advanced

Tradeoff in complexity between monolith and microservices

Which option correctly describes a tradeoff in system complexity when choosing microservices over a monolith?

A Microservices reduce deployment complexity but increase operational complexity.

B Microservices reduce both deployment and operational complexity.

C Microservices increase deployment complexity but reduce operational complexity.

D Microservices increase both deployment and operational complexity.

💡 Hint

Think about managing many services versus one application.

Microservices simplify deployment by allowing independent updates but add operational complexity due to managing many services.

❓ Architecture

advanced

Impact on fault isolation in monolith vs microservices

Which statement best explains fault isolation differences between monolithic and microservices architectures?

A Monoliths isolate faults better because all code is in one place.

B In microservices, failure in one service usually does not crash the entire system; in monoliths, failure can affect the whole app.

C Both architectures isolate faults equally well.

D In monoliths, failure in one module never affects other modules; in microservices, failure always crashes the entire system.

💡 Hint

Consider how independent services affect system stability.

Microservices isolate faults to individual services, preventing system-wide crashes; monolith failures can impact the whole app.

❓ estimation

expert

Estimating operational overhead for microservices vs monolith

If a monolithic system requires 1 full-time engineer for operations, approximately how many engineers might be needed to operate an equivalent microservices system with 10 independent services, assuming each service requires 0.3 engineer effort for operations?

A 1 engineer

B 5 engineers

C 10 engineers

D 3 engineers

💡 Hint

Multiply the number of services by the effort per service.

10 services × 0.3 engineer effort = 3 engineers needed, which is higher than monolith's 1 engineer.

Practice

1. Which of the following best describes a monolithic architecture?

easy

A. Many small independent services communicating over a network

B. A database optimized for distributed transactions

C. A cloud service that automatically scales resources

D. A single large application where all components are tightly integrated

Solution

1. Step 1: Understand monolithic architecture

   A monolithic architecture means all parts of the application are combined into one single unit.

2. Step 2: Compare with other options

   Many small independent services communicating over a network describes microservices, C cloud scaling, and D databases, not monoliths.

3. Final Answer:

   A single large application where all components are tightly integrated -> Option D

4. Quick Check:

   Monolith = single big app [OK]

Hint: Monolith = one big app, microservices = many small apps [OK]

Common Mistakes:

• Confusing microservices with monolith
• Thinking monolith means cloud scaling
• Mixing database types with architecture

2. Which syntax correctly describes a microservice in a system design diagram?

easy

A. Multiple boxes each labeled with a specific service name

B. A single box labeled 'App' containing all modules

C. A database icon connected to a single app box

D. A cloud icon with no internal components

Solution

1. Step 1: Identify microservice representation

   Microservices are shown as multiple small boxes, each representing a service.

2. Step 2: Eliminate incorrect options

   A single box labeled 'App' containing all modules shows a monolith, C shows database relation, D is too vague.

3. Final Answer:

   Multiple boxes each labeled with a specific service name -> Option A

4. Quick Check:

   Microservices = many small boxes [OK]

Hint: Microservices = many small boxes, monolith = one big box [OK]

Common Mistakes:

• Choosing single box for microservices
• Confusing database icons with services
• Ignoring service labels

3. Given a system with a monolithic app and a microservices app, which scenario shows better scaling for microservices?

medium

A. Scaling the entire monolith when only one feature needs more resources

B. Scaling only the specific microservice that handles the busy feature

C. Scaling the database only in the monolith

D. Scaling the user interface layer in the monolith

Solution

1. Step 1: Understand scaling in monolith vs microservices

   Monolith requires scaling the whole app, microservices allow scaling individual services.

2. Step 2: Identify the efficient scaling method

   Scaling only the busy microservice is more efficient and flexible than scaling the entire monolith.

3. Final Answer:

   Scaling only the specific microservice that handles the busy feature -> Option B

4. Quick Check:

   Microservices scale individual parts [OK]

Hint: Microservices scale parts; monolith scales whole app [OK]

Common Mistakes:

• Thinking monolith scales parts independently
• Confusing database scaling with app scaling
• Ignoring microservice granularity

4. A team tries to split a monolithic app into microservices but faces frequent communication failures. What is the most likely cause?

medium

A. They deployed all microservices on the same server

B. They used a single database for all microservices

C. They did not implement proper API contracts between services

D. They kept all code in one repository

Solution

1. Step 1: Identify communication needs in microservices

   Microservices communicate over APIs; clear contracts are essential to avoid failures.

2. Step 2: Analyze other options

   Using a single database or same server is possible but less likely to cause communication failures; code repo does not affect runtime communication.

3. Final Answer:

   They did not implement proper API contracts between services -> Option C

4. Quick Check:

   API contracts prevent communication failures [OK]

Hint: API contracts are key for microservice communication [OK]

Common Mistakes:

• Blaming database sharing for communication errors
• Assuming deployment location causes failures
• Confusing code repo structure with runtime issues

5. A startup plans to build a new product with a small team and expects rapid changes. Which architecture is best and why?

hard

A. Monolith, because it is simpler to develop and deploy quickly

B. Microservices, because it allows independent scaling from day one

C. Monolith, because it supports multiple databases easily

D. Microservices, because it requires fewer resources initially

Solution

1. Step 1: Consider team size and speed needs

   A small team with rapid changes benefits from simpler, faster development and deployment.

2. Step 2: Evaluate architecture fit

   Monolith is simpler to build and deploy quickly; microservices add complexity and overhead not ideal for small teams initially.

3. Final Answer:

   Monolith, because it is simpler to develop and deploy quickly -> Option A

4. Quick Check:

   Small team + fast changes = monolith [OK]

Hint: Small teams start monolith for speed, microservices add complexity [OK]

Common Mistakes:

• Choosing microservices for small teams without need
• Assuming microservices always scale better initially
• Ignoring development speed and team skills