Ali Mohammad Tarif · WritingData structures, system design and production notes from a backend and AI engineer, taught from first principles to expert level.https://tarif.dev/enDesigning real-time chat, from first idea to productionhttps://tarif.dev/blog/real-time-chat-system-design/https://tarif.dev/blog/real-time-chat-system-design/How real-time chat works: polling vs WebSockets, message ordering, receipts, presence, fan-out across servers and slow readers, with live demos and real code.Fri, 30 Oct 2026 00:00:00 GMTSystem designSystem designWebSocketsReal-timeRedisPythontohin.tarif@gmail.com (Ali Mohammad Tarif)Heaps and priority queues, from first idea to productionhttps://tarif.dev/blog/heaps-priority-queues/https://tarif.dev/blog/heaps-priority-queues/How heaps and priority queues work, from ER triage to heapq, heapify, Dijkstra, timing wheels and the asyncio scheduler, with demos and production code.Tue, 27 Oct 2026 00:00:00 GMTData structures & algorithmsData structuresHeapsPythonInterviewstohin.tarif@gmail.com (Ali Mohammad Tarif)Consistent hashing, from first idea to productionhttps://tarif.dev/blog/consistent-hashing/https://tarif.dev/blog/consistent-hashing/How consistent hashing works, from hash % N to rings, virtual nodes, jump hash, Maglev and Redis Cluster slots, with live demos and measured numbers.Fri, 23 Oct 2026 00:00:00 GMTSystem designSystem designDistributed systemsCachingRedisPythontohin.tarif@gmail.com (Ali Mohammad Tarif)Binary search, from first idea to productionhttps://tarif.dev/blog/binary-search/https://tarif.dev/blog/binary-search/How binary search works, from a guessing game to bisect, answer-space search, cache-friendly layouts, B-tree indexes and git bisect, with demos.Tue, 20 Oct 2026 00:00:00 GMTData structures & algorithmsAlgorithmsBinary searchPythonInterviewstohin.tarif@gmail.com (Ali Mohammad Tarif)Big-O notation, from first idea to productionhttps://tarif.dev/blog/big-o-complexity/https://tarif.dev/blog/big-o-complexity/How to read time and space complexity, from counting loop steps to amortized analysis, query plans and N+1 bugs, with demos and production code.Sat, 17 Oct 2026 00:00:00 GMTData structures & algorithmsAlgorithmsComplexityPythonInterviewstohin.tarif@gmail.com (Ali Mohammad Tarif)Caching, from first idea to productionhttps://tarif.dev/blog/caching-system-design/https://tarif.dev/blog/caching-system-design/How caching works, from TTLs and cache-aside to eviction, HTTP headers, stampedes and LLM caches, with two live simulators and real production code.Sat, 17 Oct 2026 00:00:00 GMTSystem designSystem designCachingRedisHTTPPythontohin.tarif@gmail.com (Ali Mohammad Tarif)Hash maps, from first idea to productionhttps://tarif.dev/blog/hash-maps/https://tarif.dev/blog/hash-maps/How hash maps and sets work, from a coat check to CPython's dict, Swiss tables and hash flooding, with demos, exercises and real production code.Sat, 17 Oct 2026 00:00:00 GMTData structures & algorithmsData structuresHashingPythonInterviewstohin.tarif@gmail.com (Ali Mohammad Tarif)Idempotency and safe retries, from first idea to productionhttps://tarif.dev/blog/idempotency-and-retries/https://tarif.dev/blog/idempotency-and-retries/Why retries double-charge and how to stop it: idempotency keys, upserts, backoff with jitter, the outbox and inbox, with live demos and real production code.Sat, 17 Oct 2026 00:00:00 GMTSystem designSystem designIdempotencyReliabilityPostgreSQLPythontohin.tarif@gmail.com (Ali Mohammad Tarif)Queues and backpressure, from first idea to productionhttps://tarif.dev/blog/queues-and-backpressure/https://tarif.dev/blog/queues-and-backpressure/How job queues work, from one producer and one worker to Little's Law, Celery tuning, retry storms and backpressure, with two live simulators and real code.Sat, 17 Oct 2026 00:00:00 GMTSystem designSystem designQueuesCeleryPythontohin.tarif@gmail.com (Ali Mohammad Tarif)Designing a rate limiter, from first idea to productionhttps://tarif.dev/blog/rate-limiter-system-design/https://tarif.dev/blog/rate-limiter-system-design/How rate limiters work, from a ten-line counter to a distributed Redis design: five algorithms, a live simulator, two classic bugs and real production code.Sat, 17 Oct 2026 00:00:00 GMTSystem designSystem designRate limitingRedisPythontohin.tarif@gmail.com (Ali Mohammad Tarif)The sliding window technique, from first idea to productionhttps://tarif.dev/blog/sliding-window/https://tarif.dev/blog/sliding-window/How the sliding window technique works, from a running sum to monotonic deques, stream windows and TCP, with step-through demos and real production code.Sat, 17 Oct 2026 00:00:00 GMTData structures & algorithmsAlgorithmsSliding windowPythonInterviewstohin.tarif@gmail.com (Ali Mohammad Tarif)The two pointers technique, from first idea to productionhttps://tarif.dev/blog/two-pointers/https://tarif.dev/blog/two-pointers/How two pointers work, from reversing a string to Floyd's cycle detection, PostgreSQL merge joins and one-pass sync diffs, with demos and exercises.Sat, 17 Oct 2026 00:00:00 GMTData structures & algorithmsAlgorithmsTwo pointersPythonInterviewstohin.tarif@gmail.com (Ali Mohammad Tarif)Congestive collapse: why our API got slower the harder we pushed ithttps://tarif.dev/blog/congestive-collapse-admission-control/https://tarif.dev/blog/congestive-collapse-admission-control/Throughput fell from 157.6 to 55 req/s as load rose, with zero errors. How a latency-derived concurrency limit fixed it, and where it stops helping.Fri, 16 Oct 2026 00:00:00 GMTProduction notesScalingLoad testingFastAPIAWStohin.tarif@gmail.com (Ali Mohammad Tarif)No lost turns: an AI reply pipeline that can’t silently drop a customerhttps://tarif.dev/blog/no-lost-turns-ai-reply-pipeline/https://tarif.dev/blog/no-lost-turns-ai-reply-pipeline/Queues lose tasks and deploys kill workers. How an owed-reply marker, a 60-second sweeper and a sent marker make sure every customer gets an answer.Fri, 16 Oct 2026 00:00:00 GMTProduction notesReliabilityCeleryPostgreSQLAI in productiontohin.tarif@gmail.com (Ali Mohammad Tarif)Pin your model IDs: when a “latest” alias tripled our pricehttps://tarif.dev/blog/pin-your-llm-model-ids/https://tarif.dev/blog/pin-your-llm-model-ids/A vendor moved a model alias and every AI feature changed model and price with no deploy. What we pin now, and why failover skips vendors without keys.Fri, 16 Oct 2026 00:00:00 GMTProduction notesAI in productionLLMOpsReliabilityGeminitohin.tarif@gmail.com (Ali Mohammad Tarif)