All guides, page 4 of 20

Newest first. Search or pick a topic.

476 guides, newest first

• Behavioral Interview Prep for Engineers: Build a Story Bank From Six ProjectsInterview prep · A plain-English guide to behavioral interviews for engineers: what they test, how to turn six projects into a story bank, STAR without sounding robotic, and conflict and failure answers, shown on one running example of a payments engineer.20 min read · Updated 25 Oct 2026
• Body-Parser's October 2026 Vulnerability Explained: Upgrade to 2.4.0 or 1.20.9Backend · A plain-English guide to the body-parser vulnerability of October 2026: why trailing bytes after a gzip body crash Node.js, how Express pulls in body-parser and how to patch, shown on one running example of an Express 4 order API.21 min read · Updated 25 Oct 2026
• Email Deliverability Explained: SPF, DKIM, DMARC and Sender ReputationBackend · A plain-English guide to email deliverability: how SPF, DKIM and DMARC prove your mail is yours, what Gmail and Yahoo require, and how bounces, spam traps and warm-up shape reputation, shown on one running example of an app sending OTP and receipt emails.23 min read · Updated 25 Oct 2026
• Engineering Manager Interview: People, Delivery and Technical Rounds ExplainedInterview prep · A plain-English guide to the engineering manager interview: the rounds, what panels score, how to answer people, delivery and project questions, and a prep plan, shown on one running example of a senior engineer's first manager loop.21 min read · Updated 25 Oct 2026
• FastMCP's October 2026 Vulnerabilities Explained: Secret Leaks and Hidden ToolsAI and GenAI · A plain-English guide to the FastMCP vulnerability fixed in 4.1.2 and 3.4.10: how a malicious MCP server could collect OAuth client secrets, why hidden tools stayed callable, and what to do now, shown on one running example of an internal agent platform.19 min read · Updated 25 Oct 2026
• Feature Flag System Design: Sticky Rollouts, Safe Defaults and Kill SwitchesSystem design · A plain-English guide to feature flag system design: targeting rules, sticky percentage rollouts, local evaluation, outages, kill switches and flag debt, shown on one running example of a food delivery checkout.24 min read · Updated 25 Oct 2026
• Frontend Memory Leaks Explained: Detached DOM, Listeners and Heap SnapshotsFrontend · A plain-English guide to frontend memory leaks: how forgotten listeners, timers, closures and caches keep removed DOM in memory, how to find them with heap snapshots, and how to fix and test them, shown on one running example of an orders dashboard panel.22 min read · Updated 25 Oct 2026
• How to Become a Staff Engineer: Scope, Influence and the Promo CaseInterview prep · A plain-English guide to the staff engineer path: what public career ladders ask for, scope vs output, the four archetypes, writing, and building a promotion case, shown on one running example of a cross-team payments bug.25 min read · Updated 25 Oct 2026
• JavaScript Code Splitting and Tree Shaking: How to Cut Bundle SizeFrontend · A plain-English guide to JavaScript code splitting and tree shaking: dynamic import() chunks, sideEffects in package.json, why CommonJS blocks shaking and size budgets, shown on one running example of a shop admin app with a heavy reports page.22 min read · Updated 25 Oct 2026
• LangGraph's October 2026 Namespace Flaw Explained: Why Dot-Joined Keys CollideAI and GenAI · A plain-English guide to the LangGraph store namespace vulnerability: why dot-joined namespaces collided, which versions fix it and how to check, shown on one running example of a multi-tenant agent memory store.18 min read · Updated 25 Oct 2026
• Machine Translation System Design: Glossaries, Quality Checks and FallbacksAI and GenAI · A plain-English guide to machine translation system design: glossaries, protected placeholders, quality estimation, translation caching, human review and fallbacks, shown on one running example of a shopping app translating order messages into Indian languages.23 min read · Updated 25 Oct 2026
• Pandas 3.1 Explained: Inplace Deprecation, Select, Filter and Faster CSV ReadsBackend · A plain-English guide to pandas 3.1: why inplace is deprecated and how to migrate, the new select and filter tools, faster read_csv and the date unit change, shown on one running example of a shop's nightly orders script.19 min read · Updated 25 Oct 2026
• Pgvector vs Vector Database: When Postgres Is Enough and When to SwitchAI and GenAI · A plain-English guide to choosing between pgvector and a dedicated vector database: recall, filters, memory and write cost measured on 100,000 vectors, shown on one running example of a help-desk article search.24 min read · Updated 25 Oct 2026
• Pillow 13 Security Update Explained (October 2026): What Image Uploads Need NowBackend · A plain-English guide to the Pillow 13 security update: what the October 2026 advisories fix, why there is no 12.x patch, and how to harden image uploads, shown on one running example of a marketplace that makes thumbnails from seller photos.20 min read · Updated 25 Oct 2026
• Presence System Design: Heartbeats, Last Seen, Fan-Out and PrivacySystem design · A plain-English guide to presence system design: heartbeats and TTL keys for online status, last seen without a write storm, contact fan-out and privacy rules, shown on one running example of a chat app.25 min read · Updated 25 Oct 2026
• Redis Internals Explained: Event Loop, RDB vs AOF and EvictionBackend · A plain-English guide to Redis internals: the single-threaded event loop, what blocks the server, RDB and AOF persistence, fork and eviction, shown on one running example of a food delivery app's Redis server.24 min read · Updated 25 Oct 2026
• Secrets Management Explained: Vaults, Short-Lived Credentials and RotationBackend · A plain-English guide to secrets management: why .env files stop scaling, how vaults and envelope encryption work, short-lived credentials, rotation and leak scanning, shown on one running example of a food delivery app.23 min read · Updated 25 Oct 2026
• Service Mesh Explained: Sidecars, mTLS, Retries and When You Need OneBackend · A plain-English guide to service meshes: what the proxies do, sidecar vs ambient mode, mTLS identities, retries, timeouts, canary traffic shifting and when Istio or Linkerd is worth it, shown on one running example of an orders service calling payments.23 min read · Updated 25 Oct 2026
• Service Workers Explained: Offline-First Caching Without Stale AppsFrontend · A plain-English guide to service workers: caching strategies per file type, the install, waiting and activate lifecycle, and safe updates, shown on one running example of a delivery riders' drop-list app.21 min read · Updated 25 Oct 2026
• Session Replay Explained: How DOM Recording Masks Passwords and PIIFrontend · A plain-English guide to session replay: how it records DOM snapshots and changes instead of video, how masking keeps passwords and PII out, what consent requires and how big recordings get, shown on one running example of a store's checkout bug.19 min read · Updated 25 Oct 2026
• Splitwise System Design: LLD for Splits, Balances and Debt SimplificationSystem design · A plain-English guide to Splitwise system design at the class level: groups, expenses, three split rules in paise, net balances and greedy debt simplification, shown on one running example of four flatmates sharing bills.23 min read · Updated 25 Oct 2026
• Storybook's October 2026 Vulnerabilities Explained: Lock Down Your Dev ServerFrontend · A plain-English guide to the two October 2026 Storybook dev server advisories: how a website or a Wi-Fi neighbour could write story files, what the fixed versions change and how to check your setup, shown on one running example of a design-system repo.20 min read · Updated 25 Oct 2026
• Trending Topics System Design: Count-Min Sketch, Top-K and Time DecaySystem design · A plain-English guide to trending topics system design: Count-Min Sketch counting, top-k lists, time decay, per-city boards and keeping bots out, shown on one running example of a social app's trending box.25 min read · Updated 25 Oct 2026
• Agent Failure Recovery: Checkpoints and Partial FailuresAI and GenAI · A plain-English guide to agent failure recovery: how checkpoints, idempotency keys and undo steps let a crashed AI agent resume safely, shown on one running example of a nightly invoice check.25 min read · Updated 24 Oct 2026