--- title: "#system-design articles | Hashnode" description: "System Design is a very important topic that can be asked in interviews and also it plays an important role in the development phase." url: "https://hashnode.com/tag/system-design" --- Tag # #system-design 3,825 posts · 890 followers [hoppvia](https://hashnode.com/@hoppvia) · [1h ago](https://hashnode.com/posts/how-to-build-a-real-time-taxi-booking-and-dispatch-system/6af4a810fe352d7842e5644b) ### [How to Build a Real-Time Taxi Booking and Dispatch System](https://hoppvia.hashnode.dev/how-to-build-a-real-time-taxi-booking-and-dispatch-system?utm_source=hashnode&utm_medium=feed) Learn how to build a real-time taxi booking and dispatch system, covering driver matching, GPS tracking, payments, backend architecture & scalability. 9 min read · [hoppvia.hashnode.dev](https://hoppvia.hashnode.dev/how-to-build-a-real-time-taxi-booking-and-dispatch-system?utm_source=hashnode&utm_medium=feed) [aleksejmenner](https://hashnode.com/@alexmen) · [5h ago](https://hashnode.com/posts/designing-an-entitlement-model-for-paid-telegram-communities/6af46d3cf50d6138ae3b8488) ### [Designing an Entitlement Model for Paid Telegram Communities](https://alexmanner.hashnode.dev/designing-an-entitlement-model-for-paid-telegram-communities?utm_source=hashnode&utm_medium=feed) Design paid Telegram access with entitlements, verified recipients, validity periods, refunds, and membership tracked separately. 14 min read · [alexmanner.hashnode.dev](https://alexmanner.hashnode.dev/designing-an-entitlement-model-for-paid-telegram-communities?utm_source=hashnode&utm_medium=feed) [Dmytro Nasyrov](https://hashnode.com/@dmytro-nasyrov) · [10h ago](https://hashnode.com/posts/casino-wallet-recovery-session-round-ledger-state/6af425dd27d0807c65d18a8e) ### [Casino Wallet Recovery: Keep Session, Round and Ledger State Separate](https://pharos-production.hashnode.dev/casino-wallet-recovery-session-round-ledger-state?utm_source=hashnode&utm_medium=feed) A three-domain ownership map and fictional late-event sequence for assigning recovery evidence. 17 min read · [pharos-production.hashnode.dev](https://pharos-production.hashnode.dev/casino-wallet-recovery-session-round-ledger-state?utm_source=hashnode&utm_medium=feed) [Neeraj Sharma](https://hashnode.com/@neeraj0786) · [10h ago](https://hashnode.com/posts/system-design-for-a-private-ai-video-studio-one-gpu-four-open-models-and-an-agent-that-directs/6af423fae410f1390d7b7b7a) ### [System Design for a Private AI Video Studio: One GPU, Four Open Models and an Agent That Directs](https://axionry.hashnode.dev/system-design-for-a-private-ai-video-studio-one-gpu-four-open-models-and-an-agent-that-directs?utm_source=hashnode&utm_medium=feed) A hosted AI video tool charges per credit and owns your workflow. A private studio on open models charges you per GPU minute and lets you keep your characters, prompts and outputs. We run one for our 5 min read · [axionry.hashnode.dev](https://axionry.hashnode.dev/system-design-for-a-private-ai-video-studio-one-gpu-four-open-models-and-an-agent-that-directs?utm_source=hashnode&utm_medium=feed) [DigiCirq](https://hashnode.com/@digicirq) · [11h ago](https://hashnode.com/posts/whatsapp-ticks-explained-one-grey-two-grey-two-blue-and-why-blue-doesn-t-always-mean-read/6af413ccc341a4521a037cba) ### [WhatsApp Ticks Explained: One Grey, Two Grey, Two Blue, and Why Blue Doesn't Always Mean Read](https://digicirq.hashnode.dev/whatsapp-ticks-explained-one-grey-two-grey-two-blue-and-why-blue-doesn-t-always-mean-read?utm_source=hashnode&utm_medium=feed) One tick is the server, two is the phone, blue is the eyes. How delivery and read receipts travel, why two grey ticks sit for days, how to read without blue. 5 min read · [digicirq.hashnode.dev](https://digicirq.hashnode.dev/whatsapp-ticks-explained-one-grey-two-grey-two-blue-and-why-blue-doesn-t-always-mean-read?utm_source=hashnode&utm_medium=feed) [1](https://hashnode.com/posts/whatsapp-ticks-explained-one-grey-two-grey-two-blue-and-why-blue-doesn-t-always-mean-read/6af413ccc341a4521a037cba) [DigiCirq](https://hashnode.com/@digicirq) · [11h ago](https://hashnode.com/posts/what-does-rate-limited-mean-twitter-discord-apis-and-the-429-error-explained/6af41315efe44f37819b4b73) ### [What Does “Rate Limited” Mean? (Twitter, Discord, APIs and the 429 Error Explained)](https://digicirq.hashnode.dev/what-does-rate-limited-mean-twitter-discord-apis-and-the-429-error-explained?utm_source=hashnode&utm_medium=feed) Rate limited means you sent requests faster than the service allows, so it refused some. What the 429 error is, how token buckets count, and why apps do it. 5 min read · [digicirq.hashnode.dev](https://digicirq.hashnode.dev/what-does-rate-limited-mean-twitter-discord-apis-and-the-429-error-explained?utm_source=hashnode&utm_medium=feed) [Parminder singh](https://hashnode.com/@param007) · [1d ago](https://hashnode.com/posts/payment-failed-money-deducted-idempotency/6af2d4383c36fe3908d4fd5a) ### [Payment failed but money deducted: how idempotency keys stop double charges](https://systemdesignwithparam.hashnode.dev/payment-failed-money-deducted-idempotency?utm_source=hashnode&utm_medium=feed) The app shows "Payment failed". A second later your phone gets an SMS: ₹2,000 debited. You tap Pay again. Now ₹4,000 is gone, and you still have no order. This post covers why this happens, the fixes 5 min read · [systemdesignwithparam.hashnode.dev](https://systemdesignwithparam.hashnode.dev/payment-failed-money-deducted-idempotency?utm_source=hashnode&utm_medium=feed) [1](https://hashnode.com/posts/payment-failed-money-deducted-idempotency/6af2d4383c36fe3908d4fd5a) [TelcoEdge Inc.](https://hashnode.com/@telcoedgeinc) · [23h ago](https://hashnode.com/posts/before-the-bill-exists-how-telecom-mediation-pipelines-turn-raw-usage-into-reliable-data/6af370ff8f45796b006e8c41) ### [Before the Bill Exists: How Telecom Mediation Pipelines Turn Raw Usage Into Reliable Data](https://telcoedgeinc.hashnode.dev/before-the-bill-exists-how-telecom-mediation-pipelines-turn-raw-usage-into-reliable-data?utm_source=hashnode&utm_medium=feed) Understand how telecom mediation systems ingest, normalize, validate, deduplicate, and process network usage records before they reach billing systems 9 min read · [telcoedgeinc.hashnode.dev](https://telcoedgeinc.hashnode.dev/before-the-bill-exists-how-telecom-mediation-pipelines-turn-raw-usage-into-reliable-data?utm_source=hashnode&utm_medium=feed) [Mukul Kumar](https://hashnode.com/@pydevgo) · [1d ago](https://hashnode.com/posts/starlink-2-5-hour-global-outage-core-network-failure/6af335c50dfe9f9020feb197) ### [Starlink's 2.5-Hour Global Outage: The Core Network Failed, Not the Satellites](https://buildopsy.hashnode.dev/starlink-2-5-hour-global-outage-core-network-failure?utm_source=hashnode&utm_medium=feed) An analysis of Starlink's 2.5-hour global outage. How ground core control planes create single points of failure for LEO satellite networks. 4 min read · [buildopsy.hashnode.dev](https://buildopsy.hashnode.dev/starlink-2-5-hour-global-outage-core-network-failure?utm_source=hashnode&utm_medium=feed) [RONI DAS](https://hashnode.com/@ronidas) · [1d ago](https://hashnode.com/posts/how-canada-s-new-real-time-rail-moves-one-payment-and-what-it-teaches-about-backend-design/6af33769d90026f2051a4213) ### [How Canada's new Real-Time Rail moves one payment, and what it teaches about backend design](https://systemdesignacademy.hashnode.dev/how-canada-s-new-real-time-rail-moves-one-payment-and-what-it-teaches-about-backend-design?utm_source=hashnode&utm_medium=feed) Payments Canada switched on a 24/7 system on 9 November 2026 that settles every payment between banks in real time. Here is how one payment travels, why the fraud checks come first, and why a bank asks before it retries. 7 min read · [systemdesignacademy.hashnode.dev](https://systemdesignacademy.hashnode.dev/how-canada-s-new-real-time-rail-moves-one-payment-and-what-it-teaches-about-backend-design?utm_source=hashnode&utm_medium=feed)