Leading a company from good to great is equivalent to driving a massive flywheel to achieve breakthroughs through the following three factors: disciplined and well-trained people; disciplined and well-trained thoughts; disciplined and well-trained actions.

Leading a company to leap from good to great is like pushing a giant flywheel to breakthrough. Disciplined people, disciplined thought and disciplined action are indispensable.

How to find your growth hack? Ryan Holiday has some advice for you. Target a few hundred or a thousand key people, not millions. Do not target all people - target the right people. Focus on new user sign-ups instead of awareness. Use growth techniques.

How to attract and nurture seed users? Here are some points to consider: Target a few hundred or a thousand key individuals, rather than millions; focus on the right people, not everyone; concentrate on new user registrations (acquisition) rather than brand awareness; growth hacking = marketing + engineering.

According to Ryan Holiday, to begin with PMF, we need to start with MVP and evolve with feedback, use data and information to back PMF, understand the needs of customers as early as possible and develop answers with the Socrates method.

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?

Failover: Failover is a backup operational mode used to enhance system stability and availability. When the primary component fails or is scheduled for downtime, the functions of system components (such as processors, servers, networks, or databases) are transferred to secondary system components.

To improve availability with failover, there are serval ways to achieve the goal such as cold standby, hot standby, warm standby, checkpointing and all active.

If you are asked to design a system to take user-provided URLs and transform them to shortened URLs, what would you do? How would you allocate the shorthand URLs? How would you implement the redirect servers? How would you store the click stats?

Lambda architecture = CQRS (batch layer + serving layer) + speed layer. It solves accuracy, latency, throughput problems of big data.