Free lesson · Microservices Interview
What This Course Covers (And What It Doesn't)
What This Course Covers (And What It Doesn't)
Before you invest time in a course, you deserve to know exactly what it will and will not teach you. This lesson draws that boundary clearly - what is inside the scope, what is deliberately excluded, and what foundational knowledge you should already have before starting.
What This Course Teaches
This course teaches microservices architecture for system design interviews. That phrase carries specific meaning, and each word in it matters.
Microservices - not distributed systems in general. Distributed systems is the broader field. Microservices is a specific architectural style within that field, with its own decomposition principles, data-management patterns, communication strategies, and operational concerns. This course focuses on the decisions and tradeoffs that are specific to building, operating, and evolving a microservices architecture. Where distributed systems fundamentals are needed (consistency models, failure semantics, CAP theorem), we reference them as prerequisites rather than re-deriving them from scratch.
Architecture - not implementation. You will not write a Spring Boot service or deploy a Kubernetes pod in this course. You will learn how to reason about service decomposition, data ownership, communication patterns, resilience strategies, and operational concerns at the level of abstraction that system design interviews operate at. The goal is architectural judgment - the ability to make decisions, justify them, and anticipate their consequences. Implementation follows from architecture, not the other way around.
System design interviews - not academic study. Everything in this course is framed through the lens of what interviewers at L5 through L7 actually evaluate. That framing affects what we cover, how we cover it, and what we spend the most time on. The Saga pattern is not presented as a theoretical concept - it is presented as a pattern you will need to propose, justify, and walk through failure scenarios for in a 45-minute interview. The emphasis is always on reasoning, tradeoffs, and communication - the three things that separate strong from weak system design performance.
The Fourteen Modules
Interactive animation: Fourteen modules in three phases - Foundations, The Hard Problems and Wisdom - answering what, how, and what actually matters.
The course is organised into three phases.
Phase 1 - Foundations and Decomposition (Modules 01–03). What microservices are, when they are the right choice, how to decompose systems into services using domain-driven design principles, and how to plan and execute a migration from monolith to microservices. This phase answers the what and why.
Phase 2 - The Hard Problems (Modules 04–11). Inter-service communication, data management across service boundaries, resilience and fault tolerance, service discovery and API gateways, observability, security, deployment and operations, and testing. This is the engineering core of the course - the modules where you learn to design the internal machinery of a microservices system and handle the complexity it creates. This phase answers the how.
Phase 3 - Wisdom (Modules 12–14). Microservices at scale (what changes when you operate hundreds of services), interview-format case studies where you design complete architectures and compare your approach to how real companies solved them, and a capstone module on anti-patterns and the hard-won lessons that senior engineers wish they had learned earlier. This phase answers the what actually matters.
Tip: If you are preparing for a specific interview and have limited time, you do not need to complete every module sequentially. The highest-leverage path for rapid preparation is:
Module 01 (Foundations) → Module 02 (Decomposition) → Module 05 (Data Management) → Module 06 (Resilience) → Module 13 (Case Studies)
These five modules cover the territory that appears most frequently in system design rounds at senior and principal levels.
Interactive animation: The five-module path for limited time: Modules 01, 02, 05, 06 and 13, in that order.
What This Course Does Not Teach
Being clear about what is excluded is as important as being clear about what is included. Several adjacent topics are deliberately outside the scope of this course.
Basic distributed systems concepts. This course does not teach you what a load balancer is, how a message queue works at a fundamental level, what eventual consistency means, or how databases replicate. These are assumed knowledge. If any of them feel unfamiliar, our System Design Fundamentals course covers them in depth. Specifically:
- Load balancing, reverse proxies, and CDNs → System Design Fundamentals, Modules 5–7
- Databases, replication, and partitioning → System Design Fundamentals, Modules 10–14
- Caching fundamentals → System Design Fundamentals, Module 8
- Message queues and pub/sub basics → System Design Fundamentals, Module 15
This course builds on top of those foundations. When a lesson references a concept from the fundamentals layer, it provides a one-paragraph refresher and a cross-link rather than a full re-teach.
Technology-specific implementation. We reference specific technologies throughout the course - Kafka, gRPC, Kubernetes, Istio, Consul, Debezium, OpenTelemetry. We explain what they do, when to choose them, and what tradeoffs they carry. We do not teach you how to configure them, write code against their APIs, or deploy them in production. That is implementation, not architecture. Our System Design Advanced course includes technology deep-dives on many of these tools if you want implementation-level depth.
Coding interview preparation. Microservices system design interviews are whiteboard architecture discussions, not coding challenges. If you are preparing for the coding round, our DSA Mastery and Coding Patterns courses cover that domain. This course is exclusively focused on the system design and architecture interview track.
Organizational and management topics. We touch on Conway's Law, team topologies, and organizational readiness where they directly affect architectural decisions. We do not cover engineering management, hiring, performance reviews, or career development. Our Career Trajectory and Promotion Strategy courses, led by Swati Bajpai, cover that territory.
Interactive animation: Four topics left out on purpose, and where each lives instead - from distributed systems basics to coding interviews.
Prerequisites Self-Check
Before starting Module 01, you should be comfortable with the following concepts. You do not need to be an expert - but you should be able to explain each one in two or three sentences without looking it up.
Distributed Systems Fundamentals
- CAP theorem - what it states, what the practical tradeoffs are between consistency and availability during a partition, and why it matters for database selection
- Consistency models - the difference between strong consistency, eventual consistency, and causal consistency, and when each is appropriate
- Replication - leader-follower replication, multi-leader replication, and the write-conflict problems each creates
- Partitioning - horizontal partitioning (sharding), partition strategies (hash-based, range-based), and the problems partitioning creates for queries that span partitions
Communication and Networking
- HTTP and REST - request/response model, status codes, idempotent methods, statelessness
- Message queues - the difference between point-to-point queues and publish-subscribe topics, at-least-once versus exactly-once delivery, dead letter queues
- Load balancing - what a load balancer does, Layer 4 versus Layer 7, health checks
Data and Storage
- Relational databases - tables, joins, transactions, ACID properties
- NoSQL databases - document stores, key-value stores, when to choose them over relational databases
- Caching - cache-aside pattern, cache invalidation, TTL
General Architecture
- Client-server architecture - how web applications work at a high level
- APIs - what an API is, the difference between synchronous and asynchronous APIs
- Scalability - horizontal versus vertical scaling, stateless services, the role of a reverse proxy
Interview: Why this self-check matters for interviews: System design interviewers at L5+ expect you to use these concepts fluently - as building blocks, not as things you are discovering for the first time during the interview. If you find yourself uncertain on more than two or three items in this list, invest time in our System Design Fundamentals course before starting this one. The depth you gain there will make every module here land more effectively.
If the items above feel solid, you are ready. Let us look at how the course is structured and how to navigate it based on your timeline and goals.