Topic / 26 published entries
Fundamentals
Core CS concepts every senior engineer must know cold — networking, security, storage, distributed systems.
fundamentals
Algorithms Practice: Arrays & Hashing
The array and hash-map patterns I practice first for interview speed: lookup, grouping, counting, prefix ideas, and duplicate detection.
Bloom Filter
Probabilistic set membership data structure — how it works, false positive rate, use cases in web crawlers, cache systems, and databases.
Caching Strategies
Cache Aside, Read Through, Write Through, Write Back, Write Around — when to use each, trade-offs, and cache invalidation patterns.
CDN Architecture
How Content Delivery Networks work — PoPs, edge caching, cache invalidation, pull vs push, and when to use a CDN.
Consistency: At-Most Once, At-Least Once, Exactly Once
Message delivery guarantees, idempotency patterns, optimistic locking, and CAP theorem trade-offs in distributed systems.
Database Isolation Levels
Read Uncommitted, Read Committed, Repeatable Read, Serializable — what anomalies each level prevents, how MVCC implements them, and which to use.
Deployment Strategies
Blue-green, canary, rolling, and feature flags — how to ship safely to production with zero downtime and controlled rollouts.
DNS + What Happens When You Type a URL
Full journey from URL to rendered page — DNS resolution, TCP, TLS, HTTP, browser rendering — with every step explained for interviews.
HTTP 1.0 → HTTP 1.1 → HTTP 2.0 → HTTP 3.0
How each HTTP version solved the previous generation's bottlenecks — persistent connections, multiplexing, QUIC, and HOL blocking.
How HTTPS Works (TLS Handshake)
TLS 1.3 handshake step-by-step — asymmetric vs symmetric encryption, certificate validation, session keys, and why HTTPS is fast.
Orchestration vs Choreography
How microservices coordinate — orchestration (central conductor), choreography (event-driven), saga pattern, and when to choose which.
Coding Practice: Arrays
Ten medium-level array questions that sharpen indexing, range handling, transformation, and mutation patterns for senior frontend engineers.
Coding Practice: Collections
Ten medium-level questions using Map, Set, WeakMap, frequency tables, grouping, caches, and lookup-heavy workflows.
Coding Practice: Graphs
Ten medium-level graph questions covering traversal, cycle detection, connectivity, dependency ordering, and shortest-path thinking.
Coding Practice: JSON & Object Transformations
Ten medium-level object and JSON transformation questions focused on payload shaping, normalization, flattening, and deep updates.
Coding Practice: Recursion and Backtracking
Ten medium-level recursion questions covering nested data, combinatorial search, branching, and backtracking control.
Coding Practice: Searching
Ten medium-level searching questions focused on binary search variants, lookup strategies, boundary conditions, and real UI data access patterns.
Coding Practice: Sorting
Ten medium-level sorting questions covering custom comparators, stable ordering, partial ordering, interval sorting, and ranked UI data.
Coding Practice: Stack and Queue
Ten medium-level stack and queue questions covering bracket validation, undo history, monotonic stacks, BFS queues, and scheduling.
Coding Practice: Strings, Sliding Window, and Two Pointers
Ten medium-level string and window questions focused on parsing, uniqueness, substring state, and pointer-based reasoning.
Coding Practice: Trees
Ten medium-level tree questions covering traversal, view building, hierarchy assembly, validation, and path-based reasoning.
Algorithms Practice: Sliding Window & Two Pointers
The patterns I use for substring, subarray, and sorted-array problems where moving boundaries beats brute force.
SSO (Single Sign-On) & OAuth 2.0
How SSO works with SAML and OAuth/OIDC, the token flow, JWT internals, and how to implement SSO in a microservices architecture.
Algorithms Practice: Stack, Queue, and Recursion
The interview patterns behind balanced brackets, monotonic stacks, BFS queues, and recursive decomposition.
Algorithms Practice: Trees, Graphs, and Dynamic Programming
A compact study map for traversal, path problems, cycle detection, and the dynamic-programming mindset.
Globally Unique ID Generation (Snowflake)
UUID vs auto-increment vs Twitter Snowflake vs ULID — how to generate 64-bit sortable unique IDs at scale across distributed systems.