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12 articlesDesigning a URL Shortener System
Design a system that can convert URLs provided by users into short URLs, allowing users to access their original long URLs using these short URLs. The operation of the system should include, but not be limited to, the following questions: How to allocate short URLs? How to store the mapping between short URLs and long URLs? How to implement the redirection service? How to store access data?
Improving System Availability through Failover
An overview of failover strategies for improving system availability, including cold, warm, and hot backups, and active-active versus active-passive configurations.
Lambda Architecture
Using Lambda can address three issues brought by big data: accuracy (good); latency (fast); throughput (high). The lambda architecture can guide us on how to scale a data system.
Nonviolent Communication (NVC)
Nonviolent Communication is not about appearing friendly, nor is it about getting others to do what we want; it concerns mutual understanding between people. There are two ways to strengthen connections and understanding between individuals: expressing our feelings and needs vulnerably; and actively listening to the feelings and needs of others.
Why is Buyer Persona Important?
KYC is not easy; employees outside the marketing department may never have the opportunity to understand buyers' needs. Buyer persona = buyer profile (who will buy) + buyer insights (when/how/why they buy)
Elements of Value
When customers evaluate a product or service, they weigh perceived value against actual price. The elements of value include functional value; emotional value; life-changing; and social impact.
What are CAC, LTV, and PBP in Marketing?
What are CAC, LTV, and PBP in marketing? CAC (Customer Acquisition Cost), LTV (Customer Lifetime Value), PBP (Payback Period). The LTV:CAC ratio helps you determine how much you should spend to acquire a customer for sustainable growth.
Skip List
A skip list is essentially a linked list that allows for binary search. It achieves this by adding extra nodes that enable you to "skip" parts of the linked list. Given a random number generator to create these extra nodes, a skip list has O(log n) complexity for search, insert, and delete operations.
Bloom Filter
A Bloom filter is a data structure that is used to determine whether an element is a member of a set with a much higher space and time efficiency than other general algorithms. The results obtained using a Bloom filter may yield false positive matches, but cannot yield false negative matches. Elements can be added to the set, but cannot be removed; the more elements added to the set, the greater the likelihood of false positives.
Mark Sellers: Technology Is Not an Economic Moat
An economic moat refers to a company's ability to maintain a competitive advantage over its rivals, protecting long-term profits and market share. Elements that do not constitute an economic moat include: technology; extensive reading; master's degrees or other degrees from top universities; experience. Elements that constitute an economic moat include: economies of scale and scope; network effects; intellectual property; high customer switching costs.
Past Work Experience Interview
A guide to past work experience interviews: how to describe projects compellingly, highlight challenges, and demonstrate learning and leadership.
What is Apache Kafka?
Apache Kafka is a distributed streaming platform. Its features include a distributed publish-subscribe (pub-sub) messaging system that simplifies N ^ 2 relationships into N, allowing publishers and subscribers to operate at their own rates; ultra-fast zero-copy technology; and support for fault-tolerant data persistence.
About Tian Pan
I'm Tian Pan, an engineer-founder focused on agentic engineering — building autonomous AI systems and scaling engineering teams. I write practical guides on system design, technical leadership, and shipping with AI agents. Previously an early engineer at Uber, Brex, and IoTeX.
