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Foundation lessons plus a few deeper ones, from both the System Design + LLD path and the AI Systems path. Same voice. Same examples. Same focus on tradeoffs. See pricing and full access →
What System Design Actually Is
What system design rounds test in Indian companies, and what interviewers look for beyond textbook diagrams.
How the Internet Actually Works
How requests travel from a browser or app to a backend service, using DNS, TCP, and HTTP.
The 30 Must-Know Concepts
The core thirty concepts you need to speak comfortably in backend architecture interviews.
Scalability vs Availability vs Reliability
The practical differences and tradeoffs between scaling out, staying up, and staying correct.
Latency vs Throughput vs Bandwidth
How to calculate and talk about latency percentiles, throughput limits, and bandwidth bottlenecks.
CAP Theorem & Consistency Models
How network partitions force a choice between availability and consistency in distributed data stores.
Consistent Hashing
Why distributed caches and databases use hash rings to add nodes without massive key movement.
Load Balancing 101
Algorithms, health checks, and failure modes when distributing requests across a fleet.
Cache Invalidation & Stampede
How to protect databases during peak traffic events like Big Billion Days when hot keys expire.
Resilience Patterns
Circuit breakers, bulkheads, and graceful degradation patterns drawn from real outages.
Circuit Breakers
Closed, open, and half-open states with failure patterns from production payment and order flows.
Interview Framework & Pattern Library
A repeatable timetable to structure a 45-minute system design interview round without panicking.
Pattern: kill the inner loop
How to spot when a nested loop can collapse into a single pass with a hash map.
Thinking in Objects, Not Boxes
How to drop from high-level boxes into concrete classes with real invariants and state.
Design a Rate Limiter (LLD)
Class modeling and algorithm choices for an in-memory rate limiter that survives concurrency.
What a Class Is Actually For
Why classes exist to protect invariants, using an e-commerce wallet ledger example.
Class Diagrams Without the UML Police
How to read and draw associations, composition, and inheritance without getting lost in UML minutiae.
Finding the Objects in the Prompt
How to break down an open-ended interview prompt into actors, use cases, and four clean classes.