All guides, page 12 of 21

Newest first. Search or pick a topic.

482 guides, newest first

• Design a Unique ID Generator (Snowflake): Sortable IDsSystem design · A plain-English guide to designing a unique ID generator like Snowflake, built on one running example of a Lucknow story-sharing app.26 min read · Updated 22 Oct 2026
• URL Shortener System Design: Keys, Redirects and ClicksSystem design · A plain-English guide to designing a URL shortener, from short keys and fast redirects to click analytics, built on one running SMS campaign example.24 min read · Updated 22 Oct 2026
• Webhook Design: Retries, Signatures and OrderingBackend · A plain-English guide to webhook design: retries, HMAC signatures, duplicates, ordering and safe URLs, shown on one running example of a freight-booking platform.23 min read · Updated 22 Oct 2026
• YouTube System Design: Upload, Transcode and StreamSystem design · A plain-English guide to designing a YouTube-like video platform, from resumable uploads to transcoding and adaptive streaming, shown on one running example of a regional video app.28 min read · Updated 22 Oct 2026
• Agent Harness Explained: The Code That Turns an LLM Into an AgentAI and GenAI · A plain-English guide to the agent harness: the prompts, tools, memory, guardrails and loop around a model, and why October 2026 research tunes the harness instead of the model, shown on one running example of an order-support agent.19 min read · Updated 22 Oct 2026
• Database Replication: Primary-Backup, Multi-Primary and QuorumsSystem design · A plain-English guide to database replication, from primary-backup and failover to multi-primary and quorums, built on one running payments ledger example.26 min read · Updated 22 Oct 2026
• DSpark Speculative Decoding Explained: Block Drafting and Confidence ChecksAI and GenAI · A plain-English guide to DSpark speculative decoding: how a small model drafts tokens, how the large model checks them, and how block drafting and confidence scheduling speed up serving, shown on one running example of a travel-booking chatbot.21 min read · Updated 22 Oct 2026
• eMudhra's October 2026 CA Compromise Explained: Weak Keys and What to UpdateBackend · A plain-English guide to the eMudhra certificate compromise: why eight intermediate CA keys were guessable, how browsers blocked them in hours, and what servers must update, shown on one running example of a Python payments service in an old Docker image.20 min read · Updated 22 Oct 2026
• Multi-Perspective Issuance Corroboration Explained: How CAs Outvote BGP HijacksBackend · A plain-English guide to multi-perspective issuance corroboration (MPIC): how certificate authorities confirm domain checks from several networks, what changes on 15 December 2026 and which BGP hijacks it stops, shown on one running example of a small online store renewing its certificate.20 min read · Updated 22 Oct 2026
• PHP's October 2026 PHP2Shell Bugs Explained: How to Patch and VerifyBackend · A plain-English guide to PHP2Shell, the two critical PHP remote code execution bugs fixed on 21 October 2026: how they work, who is at risk and how to patch and verify, shown on one running example of a small online store's Ubuntu server.21 min read · Updated 22 Oct 2026
• WebSockets vs SSE vs Long Polling: Real-Time Options and CostsBackend · A plain-English guide to short polling, long polling, server-sent events and WebSockets: how each works, what each costs and how to choose, shown on one running example of a live auction site.26 min read · Updated 22 Oct 2026
• Design an Ad Click Aggregator: Counting Each Click OnceSystem design · A plain-English guide to ad click aggregator design: removing duplicate clicks, counting each click in the minute it happened and surviving crashes, shown on one running example of an ad network that bills per click.28 min read · Updated 21 Oct 2026
• Design an Ad Click Prediction System: CTR, Calibration, AuctionsAI and GenAI · A plain-English guide to ad click prediction: CTR models, features, calibration, auctions, training data and serving, shown on one running example of an ad network inside news apps.24 min read · Updated 21 Oct 2026
• Agent Context Handoff: What to Pass, Summarise or DropAI and GenAI · A plain-English guide to agent context handoff: what one AI agent or long session should pass, summarise or drop for the next, built on one running tender-bid example.27 min read · Updated 21 Oct 2026
• AI Bias Testing: Fairness Checks for LLM FeaturesAI and GenAI · A plain-English guide to AI bias testing for LLM features: slicing tests by group, counterfactual pairs and the four-fifths alarm, shown on one running example of a job-matching app.23 min read · Updated 21 Oct 2026
• Design an AI Chat Assistant: System Design WalkthroughAI and GenAI · A plain-English guide to AI chat assistant system design: streaming, chat storage, context budgets, quotas, a model gateway, safety, regions and cost, shown on one running example of a multilingual chat app.27 min read · Updated 21 Oct 2026
• AI Engineer Interview Prep: Rounds, Questions and Study PlanInterview prep · A plain-English guide to the AI engineer interview loop: each round, sample questions, tested code and an 8-week study plan, shown on one running example of an invoice question assistant.27 min read · Updated 21 Oct 2026
• AI Governance for Startups: Intake, Risk Register and Sign-offAI and GenAI · A plain-English guide to a light AI governance framework for startups, with an intake form, risk tiers, a risk register and sign-off rules, built on one running home-loan marketplace example.25 min read · Updated 21 Oct 2026
• AI Incident Response: When Your AI Gets It Wrong in PublicAI and GenAI · A plain-English guide to AI incident response: kill switches, honest communication and blameless post-mortems, built on one running bus ticket chatbot example.24 min read · Updated 21 Oct 2026
• No-Code AI Workflows vs Writing Code: When Each One WinsAI and GenAI · A plain-English guide to AI workflow automation that shows when a no-code flow beats custom code or an agent, and when it does not, using one running example of a small candle shop.25 min read · Updated 21 Oct 2026
• API Latency Budgets: Estimating Response TimeBackend · A plain-English guide to API latency estimation: add up every hop, handshake and parallel call, set a p99 budget and check it, shown on one running example of a truck-hire quote API.28 min read · Updated 21 Oct 2026
• The 2020 AWS Kinesis Outage Explained: Threads and LessonsSystem design · A plain-English guide to the November 2020 AWS Kinesis outage: the thread limit behind it, why recovery was slow, how it spread and the design lessons, shown on one running example of a clickstream analytics pipeline.25 min read · Updated 21 Oct 2026
• How Bigtable and HBase Work: LSM Trees and TabletsSystem design · A plain-English guide to how Bigtable and HBase store data with LSM trees, compaction and tablets, built on one running air-quality sensor example.26 min read · Updated 21 Oct 2026
• Block vs File vs Object Storage: Which Fits Which JobSystem design · A plain-English guide to block, file and object storage, what each is good at and how to choose, built on one running cooperative bank example.27 min read · Updated 21 Oct 2026