Manipulate a simplified commit graph to see how Git objects, branches, HEAD, merge, rebase, reset, and cherry-pick fit together.
A structured path through complexity, core data structures, recursion, memory, trees, graphs, and dynamic programming.
A visual path through memory, processes, concurrency, virtual memory, and CPU caching.
Connect scheduling and runtime fundamentals to responsive mobile apps and the networks they depend on.
Follow a request from the network edge through a secure API, indexed data access, and authoritative state changes.
Build from tree-shaped indexes to concurrent transactions, isolation, and durable state changes.
Follow production requests through security, retries, queues, caches, telemetry, and authoritative state.
Design resilient Expo apps from identity and offline state through performance, notifications, testing, and shipping.
Core data structures and algorithms explained with interactive visualizers.
Building, shipping, and maintaining production mobile apps with Expo.
APIs, edge runtimes, validation, and the infrastructure behind the apps.
Store submissions, monetization, and everything between code and release.
Reusable approaches to problems that show up across real codebases.
Memory, processes, concurrency, operating systems, and the low-level concepts behind software.
Indexes, transactions, consistency, and the concurrency rules behind durable data.
The internal models behind tools developers use every day.
Send traffic through fixed-window, sliding-window, and token-bucket limiters to compare bursts, fairness, state, 429 responses, and refill behavior.
Inspect trace waterfalls, correlated logs, span errors, latency, throughput, and retries to find where a distributed request actually failed.
Trace a notification from an Expo backend through APNs or FCM into foreground, background, and terminated app states—and then into a deep link.
Send requests through memory, browser, CDN, API, and database layers while changing TTL, capacity, frequency, staleness, and revalidation.
Watch producers, queues, workers, retries, duplicate deliveries, backpressure, and dead-letter handling change under real failure scenarios.
Change table size, selectivity, and available indexes to see a conceptual planner choose scans and joins—and learn to read EXPLAIN ANALYZE safely.
Interleave two transactions and see lost updates, snapshots, row locks, deadlocks, and PostgreSQL serialization failures as they happen.
Use trust boundaries, authorization, validation, idempotency, transactions, and server-owned rules to keep mobile games and APIs correct under tampering and retries.
Follow fetch through DNS, connection security, edge infrastructure, authentication, cache, database, serialization, retries, and the final UI update.
See how JavaScript, React rendering, native/UI work, lists, images, and state updates compete for a frame—and which optimizations actually help.
Explore page-oriented B-Tree indexes, splits, range scans, composite keys, selectivity, and the tradeoff between faster reads and more expensive writes.
Step through the call stack, runtime APIs, microtasks, tasks, and rendering opportunities—and see why asynchronous JavaScript can still freeze an app.
See how cache lines, locality, access order, and finite capacity make two algorithms with the same Big O behave differently on real hardware.
Follow a virtual address through the TLB and page table to physical memory, including page faults, protection, and the limits of the model.
See how processes isolate resources, threads share state, schedules interleave, and synchronization prevents races while creating new tradeoffs.
How the organization of linear data makes indexing, insertion, removal, and traversal cheap or expensive.
From repeated recursion to carefully defined states, memoization, tabulation, and the tradeoffs behind dynamic programming.
Why a binary heap keeps the next priority at the root, maps naturally to an array, and supports efficient scheduling.
Recursion explained as ordinary function calls, pending stack frames, base cases, and a controlled return journey.
A careful conceptual model of call frames, dynamic allocation, ownership, lifetime, and what managed runtimes can change.
Tree vocabulary, binary-search-tree invariants, deletion cases, traversals, and why balance determines performance.
Retries are normal. Idempotency makes important API operations safe to retry without pretending distributed systems can guarantee magic exactly-once execution.
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.
A production testing matrix for React Native apps: installation, authentication, offline behavior, purchases, lifecycle changes, and data migrations.