Tutorials

Practical engineering guides, interactive visualizations, and lessons from building and shipping real software.

Computer Systems

CPU Caches and Locality Visualized

See how cache lines, locality, access order, and finite capacity make two algorithms with the same Big O behave differently on real hardware.

September 4, 20268 min readRead

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All Tutorials

Virtual Memory Visualized: Pages, Page Tables and Address Translation

Follow a virtual address through the TLB and page table to physical memory, including page faults, protection, and the limits of the model.

Computer Systems

Operating Systems

September 4, 20268 min read

Processes, Threads and Concurrency Visualized

See how processes isolate resources, threads share state, schedules interleave, and synchronization prevents races while creating new tradeoffs.

Computer Systems

Race Conditions

Synchronization

Operating Systems

September 4, 20268 min read

Arrays, Linked Lists, Stacks and Queues Visualized

How the organization of linear data makes indexing, insertion, removal, and traversal cheap or expensive.

Algorithms Visualized

Data Structures

September 4, 20265 min read

Dynamic Programming Visualized

From repeated recursion to carefully defined states, memoization, tabulation, and the tradeoffs behind dynamic programming.

Algorithms Visualized

Dynamic Programming

September 4, 20264 min read

Heaps and Priority Queues Visualized

Why a binary heap keeps the next priority at the root, maps naturally to an array, and supports efficient scheduling.

Algorithms Visualized

Data Structures

September 4, 20264 min read

Recursion and the Call Stack Visualized

Recursion explained as ordinary function calls, pending stack frames, base cases, and a controlled return journey.

Algorithms Visualized

Computer Science

September 4, 20264 min read

Stack vs Heap: How Memory Works

A careful conceptual model of call frames, dynamic allocation, ownership, lifetime, and what managed runtimes can change.

Computer Systems

Computer Systems

September 4, 20264 min read

Trees and Binary Search Trees Visualized

Tree vocabulary, binary-search-tree invariants, deletion cases, traversals, and why balance determines performance.

Algorithms Visualized

Binary Search Trees

Data Structures

September 4, 20264 min read

Designing Retry-Safe APIs with Idempotency

Retries are normal. Idempotency makes important API operations safe to retry without pretending distributed systems can guarantee magic exactly-once execution.

Backend & Cloud

Distributed Systems

September 4, 20267 min read

Implementing Secure Account Deletion in Expo and Supabase

Account deletion in an Expo app is a controlled workflow: confirm intent, authenticate the caller, clean up data and providers, then remove the identity safely.

React Native & Expo

Account Deletion

September 4, 20267 min read

Testing the States That Break Mobile Apps

A production testing matrix for React Native apps: installation, authentication, offline behavior, purchases, lifecycle changes, and data migrations.

Engineering Patterns

September 4, 20266 min read

Apple and Google Sign-In with Expo and Supabase

A production-minded approach to social sign-in in Expo: native Apple credentials, OAuth redirects, Supabase sessions, secure storage, and the identity edge cases that affect real users.

React Native & Expo

September 4, 20269 min read

Building an Offline-First React Native App

A practical architecture for React Native apps that remain useful without a connection: local source of truth, migrations, sync queues, conflicts, and honest failure handling.

Engineering Patterns

September 4, 20268 min read

RevenueCat + Expo: Subscriptions, Lifetime Purchases, and Restore

How to add in-app purchases to an Expo app with RevenueCat: entitlements over product IDs, why restore is mandatory, and why the client is the wrong place to trust a purchase.

Shipping Products

September 4, 202610 min read

Building a Secure API with Cloudflare Workers, Zod, and Rate Limiting

Validating every input at the edge, rate limiting without a database, and using signed state so a client can hold data it cannot forge.

Backend & Cloud

Cloudflare Workers

September 4, 202610 min read

How to Ship a React Native Expo App to the App Store with EAS

The full path from a working Expo project to an approved App Store release: build profiles, credentials, versioning, TestFlight, and the review rejections that are easiest to avoid.

React Native & Expo

September 4, 202610 min read

Big O Notation Visualized: Understanding Time Complexity

What Big O actually measures, how each growth class behaves as input grows, and when complexity decides your architecture versus when it is the wrong thing to optimize.

Algorithms Visualized

September 4, 202613 min read

Binary Search Visualized

A step-by-step guide to binary search, including the core invariant, common implementation bugs, and why halving the search interval changes performance completely.

Algorithms Visualized

February 28, 20268 min read

Graph Algorithms Part 2: Dijkstra and Topological Sort

Visualize shortest paths with Dijkstra's algorithm and understand dependency resolution with Topological Sort (Kahn's algorithm).

Algorithms Visualized

February 1, 20267 min read

Graph Traversal Algorithms Visualized

A visual guide to exploring graphs using Breadth-First Search (BFS) and Depth-First Search (DFS), and understanding how traversal strategy affects performance and behavior.

Algorithms Visualized

Data Structures

February 1, 20265 min read

Hash Tables Visualized

A visual guide to how hash tables really work: hashing, collisions, probing, resizing, and why performance can collapse if you ignore the details.

Algorithms Visualized

Data Structures

January 25, 20266 min read

Advanced Sorting Algorithms Visualized

Explore non-comparison sorting algorithms and selection algorithms including QuickSelect, Counting Sort, and Lexicographic Counting Sort.

Algorithms Visualized

Data Structures

January 18, 20269 min read

Sorting Algorithms Visualized

A visual guide to understanding common sorting algorithms including Bubble Sort, Selection Sort, Insertion Sort, Quick Sort, and Merge Sort.

Algorithms Visualized

Data Structures

January 11, 202610 min read