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.

Customer Acquisition Cost is the cost to convert a customer to buy a product/service. Lifetime Value is the estimated net profit we can make from a customer. Payback Period refers to the period of time required to recoup the funds expended in an investment.

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.

There are several tools for the public API, API gateway or Backend for Frontend gateway. GraphQL distinguishes itself from others for its features like tailing results, batching nested queries, performance tracing, and explicit caching.

An economic moat is the ability to maintain advantages over its competitors. It can provide protection for business’ long-term profits and market share. Technology is not an economic moat as it will always be duplicated.

Target Audience

An interview is a process for workers to find future co-workers. The candidate will be evaluated based on answers to three key questions: capability, willingness, and culture-fit. Any question above can not be answered without good communication.

Apache Kafka is a distributed streaming platform, which can be used for logging by topics, messaging system geo-replication or stream processing. It is much faster than other platforms due to its zero-copy technology.

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.

In the battle ground, if you don’t sleep, you’ll burn out pretty quickly and make bad decisions. The principle for falling asleep within 120 seconds is to relax the whole body one part by another and not to think.

On the battlefield, if you don't sleep, you will quickly feel exhausted, make wrong decisions, feel burdened by your mission, and become a liability. You can fall asleep quickly by: gradually relaxing your entire body, avoiding thoughts; stretching your body; relaxing your facial muscles, slowing everything down; relaxing your upper body; relaxing your legs; thinking of nothing at all.

What characteristics do good managers possess? Morality, benevolence, righteousness, propriety: The Dao represents truth, the laws governing the development of the world and humanity; virtue is about serving the people and creating products and services that the public enjoys efficiently; benevolence is empathy; righteousness is fairness and justice, rewarding good deeds and punishing wrongdoings; propriety involves adhering to rules and behaving in accordance with the needs of the community.