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Links
Resumegoogle drive第三人称：Chris Zhong is a Software Engineer with 2 years of experience in software development. At BOCUSA and Fiserv, he worked on scalable microservices, Kafka, and CI/CD pipelines, improving API latency and system reliability. He h...…
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StreamBuffer
Scannertry to aviod using scanner, because read each line contains an I/O operation.BufferReader will preload a batch of data. (efficient)// 此种情况适用于按token读取，如果有换行符和空格则无法区别行public static int[][] mat;public static void main() { BufferReader br = ...…
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UB Phone
Graph 成环问题（Service Dependency）基本解法 用 DFS + 三色标记，判断有向图是否存在环 或使用 拓扑排序（Topological Sort），若无法完成所有节点的排序则说明存在环Follow-up 1：多个 dependency array 如何处理？ 可以先对每个 dependency array 单独建图并分别判断是否有环 若每个 array 均无环，再将它们合并成一个整体图进行最终判断（Batch Processing） 也可以直接将所有 de...…
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Search design
Common ProblemsDesign FB Post SearchUnderstanding the Problem🔍 What is Facebook? Facebook is a social network centered around “posts” (messages). Users consume posts via a timeline composed of posts from users they follow or more recently, that th...…
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Kafka Dead Letter Queue
OverviewA Kafka Dead Letter Queue is an essential part of building robust, fault-tolerant data pipelines. Kafka’s distributed nature makes it highly reliable, but that does not mean every message will be successfully processed. Data errors, consum...…
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System design - Url Shorterner
clairify requirements & back-of-the-envelope estimationurl shortern basiclly need to handle 2 flow: user give a long url, return a short url user type a short url, redirect to original urlWill cover this later, focus on algorithm & deep ...…
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System design basic - Unique ID generator
Common way to generate Unique ID in distributed systemIn distributed system, it is not enough to rely on auto_increment provided by a transactional database.multi-master replication:Suppose we have k databases, each database increase by k, there w...…
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System design basic - consistent hasing
Round RobinserverIndex = hash(key) % n: you have n cache servers, want to balance the load, then use: serverIndex = hash(key) % nIt is simple but when there is a server offline, n changed, it need rehashing and all server are routed to different c...…
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System design - Rate limiter
Rate Limitera rate limiter is used to control the rate of traffic sent by a client or aservice.why prevent Dos attach to prevent prevent server overload reduce cost if using third party api, like retireve balanceimplement client side: throttle ...…
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System design basic - Concurrency Race Condition
Race Condition…
