Who is the Senior/Staff path for?

Engineers who already build services and want to reason clearly about consistency, consensus, multi-region and failure, the topics a Staff or Principal loop goes deep on.

Does it skip the basics?

Yes. It starts at consistency models. If a word is new, the Foundations path covers it, and every lesson still defines its terms.

What does a staff-level mock interview change?

The AI interviewer is told your level. At staff level it expects you to drive the conversation, name the trade-offs yourself, and talk about failure and operations without being asked.

A week-by-week plan · System Design

Senior/Staff Depth

For engineers five or more years in, filling the gaps before a Staff or Principal loop. You can argue for a consistency model, a consensus approach and a multi-region layout, and say how you would see each one fail.

6 steps
37 lessons
0 free
1 mock interview
18 hours of reading

Start with Data Consistency Models

Who it is for

Engineers five or more years in, filling the gaps before a Staff or Principal loop.

What you can do at the end

You can argue for a consistency model, a consensus approach and a multi-region layout, and say how you would see each one fail.

First milestone

Consistency, consensus, multi-region and observability, finished with a staff-level mock interview.

Week 6: Observability

0 of the 37 lessons are free to read now, with no account. The other 37 are in the System Design Masterclass course: $49 once, lifetime access, pay with PayPal.

Get System Design · $49

The plan, week by week

Times are each lesson’s own reading time, added up. A mock interview is set to 45 minutes. A lock means the lesson is in the course.

Week 1
Consistency models
155 min
Say exactly what a reader can see after a write, model by model.
1. Data Consistency ModelsSystem Design lesson20 minin the course
2. LinearizabilitySystem Design lesson25 minin the course
3. Sequential ConsistencySystem Design lesson20 minin the course
4. Causal ConsistencySystem Design lesson20 minin the course
5. Read-Your-WritesSystem Design lesson20 minin the course
6. Snapshot IsolationSystem Design lesson25 minin the course
7. SerializabilitySystem Design lesson25 minin the course
Week 2
Consensus and coordination
250 min
Agree on one answer when machines fail and messages arrive late.
1. Consensus AlgorithmsSystem Design lesson35 minin the course
2. Leader ElectionSystem Design lesson35 minin the course
3. QuorumSystem Design lesson52 minin the course
4. Split-BrainSystem Design lesson43 minin the course
5. Distributed LocksSystem Design lesson30 minin the course
6. Lamport TimestampsSystem Design lesson25 minin the course
7. Vector ClocksSystem Design lesson30 minin the course
Week 3
Transactions across services
159 min
Keep data correct when one business action touches many services.
1. Two-Phase CommitSystem Design lesson40 minin the course
2. Saga PatternSystem Design lesson30 minin the course
3. Transactional Outbox PatternSystem Design lesson22 minin the course
4. Exactly-Once DeliverySystem Design lesson22 minin the course
5. Idempotent ConsumerSystem Design lesson20 minin the course
6. CRDTsSystem Design lesson25 minin the course
Week 4
Multi-region
170 min
Run in more than one region, and choose what to give up.
1. Multi-Region DeploymentSystem Design lesson22 minin the course
2. Geo-ReplicationSystem Design lesson18 minin the course
3. Active-Active ConfigurationSystem Design lesson22 minin the course
4. Replication LagSystem Design lesson18 minin the course
5. Disaster RecoverySystem Design lesson25 minin the course
6. Design a Multi-Region DeploymentSystem Design lesson65 minin the course
Week 5
Designing for failure
170 min
Keep the most important part working while something else is down.
1. Circuit Breaker for ResilienceSystem Design lesson35 minin the course
2. Bulkhead PatternSystem Design lesson35 minin the course
3. Backpressure for ResilienceSystem Design lesson35 minin the course
4. Load SheddingSystem Design lesson20 minin the course
5. Graceful DegradationSystem Design lesson25 minin the course
6. Chaos EngineeringSystem Design lesson20 minin the course
Week 6
Observability
150 min
Know it is broken before your users tell you.
milestone: Consistency, consensus, multi-region and observability, finished with a staff-level mock interview.
1. Observability OverviewSystem Design lesson15 minin the course
2. Distributed TracingSystem Design lesson25 minin the course
3. SLO EngineeringSystem Design lesson20 minin the course
4. Error BudgetsSystem Design lesson25 minin the course
5. Alert Fatigue PreventionSystem Design lesson20 minin the course
6. Mock interview: design Apache KafkaAI interviewer, staff level45 min

Questions about this path

Who is the Senior/Staff path for?: Engineers who already build services and want to reason clearly about consistency, consensus, multi-region and failure, the topics a Staff or Principal loop goes deep on.
Does it skip the basics?: Yes. It starts at consistency models. If a word is new, the Foundations path covers it, and every lesson still defines its terms.
What does a staff-level mock interview change?: The AI interviewer is told your level. At staff level it expects you to drive the conversation, name the trade-offs yourself, and talk about failure and operations without being asked.

This path runs through the System Design course. Here is the whole course, at your price.

The course this path is part of

System Design Masterclass

770 lessons · about 283 hours · 18 free to read

$49 once, lifetime access · pay with PayPal

Get System Design · $49 Read 18 lessons free first

Also from me

AI Engineering

204 lessons · about 211 hours · 10 free to read

$49 once, lifetime access · pay with PayPal

Get AI Engineering · $49 Read 10 lessons free first

Either course includes the AI tutor beside every lesson, 10 questions a day, and the full seven-stage mock interview. Try a mock interview

Other paths

System Design Foundations Interview in 30 Days AI Engineer Foundations Production Agents

A week-by-week plan · System Design

Senior/Staff Depth

6 steps
37 lessons
0 free
1 mock interview
18 hours of reading

Start with Data Consistency Models

Who it is for

Engineers five or more years in, filling the gaps before a Staff or Principal loop.

What you can do at the end

You can argue for a consistency model, a consensus approach and a multi-region layout, and say how you would see each one fail.

First milestone

Consistency, consensus, multi-region and observability, finished with a staff-level mock interview.

Week 6: Observability

0 of the 37 lessons are free to read now, with no account. The other 37 are in the System Design Masterclass course: $49 once, lifetime access, pay with PayPal.

Get System Design · $49

The plan, week by week

Times are each lesson’s own reading time, added up. A mock interview is set to 45 minutes. A lock means the lesson is in the course.

Week 1
Consistency models
155 min
Say exactly what a reader can see after a write, model by model.
1. Data Consistency ModelsSystem Design lesson20 minin the course
2. LinearizabilitySystem Design lesson25 minin the course
3. Sequential ConsistencySystem Design lesson20 minin the course
4. Causal ConsistencySystem Design lesson20 minin the course
5. Read-Your-WritesSystem Design lesson20 minin the course
6. Snapshot IsolationSystem Design lesson25 minin the course
7. SerializabilitySystem Design lesson25 minin the course
Week 2
Consensus and coordination
250 min
Agree on one answer when machines fail and messages arrive late.
1. Consensus AlgorithmsSystem Design lesson35 minin the course
2. Leader ElectionSystem Design lesson35 minin the course
3. QuorumSystem Design lesson52 minin the course
4. Split-BrainSystem Design lesson43 minin the course
5. Distributed LocksSystem Design lesson30 minin the course
6. Lamport TimestampsSystem Design lesson25 minin the course
7. Vector ClocksSystem Design lesson30 minin the course
Week 3
Transactions across services
159 min
Keep data correct when one business action touches many services.
1. Two-Phase CommitSystem Design lesson40 minin the course
2. Saga PatternSystem Design lesson30 minin the course
3. Transactional Outbox PatternSystem Design lesson22 minin the course
4. Exactly-Once DeliverySystem Design lesson22 minin the course
5. Idempotent ConsumerSystem Design lesson20 minin the course
6. CRDTsSystem Design lesson25 minin the course
Week 4
Multi-region
170 min
Run in more than one region, and choose what to give up.
1. Multi-Region DeploymentSystem Design lesson22 minin the course
2. Geo-ReplicationSystem Design lesson18 minin the course
3. Active-Active ConfigurationSystem Design lesson22 minin the course
4. Replication LagSystem Design lesson18 minin the course
5. Disaster RecoverySystem Design lesson25 minin the course
6. Design a Multi-Region DeploymentSystem Design lesson65 minin the course
Week 5
Designing for failure
170 min
Keep the most important part working while something else is down.
1. Circuit Breaker for ResilienceSystem Design lesson35 minin the course
2. Bulkhead PatternSystem Design lesson35 minin the course
3. Backpressure for ResilienceSystem Design lesson35 minin the course
4. Load SheddingSystem Design lesson20 minin the course
5. Graceful DegradationSystem Design lesson25 minin the course
6. Chaos EngineeringSystem Design lesson20 minin the course
Week 6
Observability
150 min
Know it is broken before your users tell you.
milestone: Consistency, consensus, multi-region and observability, finished with a staff-level mock interview.
1. Observability OverviewSystem Design lesson15 minin the course
2. Distributed TracingSystem Design lesson25 minin the course
3. SLO EngineeringSystem Design lesson20 minin the course
4. Error BudgetsSystem Design lesson25 minin the course
5. Alert Fatigue PreventionSystem Design lesson20 minin the course
6. Mock interview: design Apache KafkaAI interviewer, staff level45 min

Questions about this path

Who is the Senior/Staff path for?: Engineers who already build services and want to reason clearly about consistency, consensus, multi-region and failure, the topics a Staff or Principal loop goes deep on.
Does it skip the basics?: Yes. It starts at consistency models. If a word is new, the Foundations path covers it, and every lesson still defines its terms.
What does a staff-level mock interview change?: The AI interviewer is told your level. At staff level it expects you to drive the conversation, name the trade-offs yourself, and talk about failure and operations without being asked.

This path runs through the System Design course. Here is the whole course, at your price.

The course this path is part of

System Design Masterclass

770 lessons · about 283 hours · 18 free to read

$49 once, lifetime access · pay with PayPal

Get System Design · $49 Read 18 lessons free first

Also from me

AI Engineering

204 lessons · about 211 hours · 10 free to read

$49 once, lifetime access · pay with PayPal

Get AI Engineering · $49 Read 10 lessons free first

Either course includes the AI tutor beside every lesson, 10 questions a day, and the full seven-stage mock interview. Try a mock interview

Other paths

System Design Foundations Interview in 30 Days AI Engineer Foundations Production Agents

The plan, week by week

Consistency models

Consensus and coordination

Transactions across services

Multi-region

Designing for failure

Observability

Questions about this path

This path runs through the System Design course. Here is the whole course, at your price.

System Design Masterclass

AI Engineering

Other paths

The plan, week by week

Consistency models

Consensus and coordination

Transactions across services

Multi-region

Designing for failure

Observability

Questions about this path

This path runs through the System Design course. Here is the whole course, at your price.

System Design Masterclass

AI Engineering

Other paths