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Simple, practical guide to the first and often-most-used approach to scaling: making copies of what works. No PhD required — just common sense, a few engineering patterns, and awareness of the pitfalls.By Your Friendly Engineer · Part 1 in a short series on practicalscalability. Acloneis simply anot

Overview:A compact guide to the main topics you’ll encounter when designing modern software systems — principles, patterns, trade-offs, and practical concerns for reliable, scalable, and maintainable systems.Audience:engineers, technical leads, and architects looking for a structured checklist and a

TheCAP theoremis one of the most fundamental principles in distributed system design. It defines the trade-offs between three key properties —Consistency,Availability, andPartition tolerance— and explains why it’s impossible to achieve all three simultaneously in a distributed data system. Formally

Consistency is one of the foundational concerns when designing distributed systems. It answers the question:when a client reads data, how fresh or correct should that data be compared to the most recent write?Different applications have different tolerances for stale or conflicting data. This articl

What availability means, how it's measured, architectural patterns that improve it, practical trade-offs, and how to validate an availability target. Availabilityis the probability that a system performs its required function at a given point in time. Practically, it answers the question:“Is the ser

Modern software systems must handle rapid growth, unpredictable load, and unexpected failures — all without compromising user experience. Three key pillars define such systems:scalability,availability, andstability. Each comes with its own design patterns and trade-offs that engineers use to build r

Caching is the process of temporarily storing frequently accessed data in a faster storage layer to reduce latency, save computation, and improve system scalability. Instead of recomputing or refetching data from a slower source like a database or API, a cache serves it quickly from memory or nearby

Scalability is the ability of a system to handle increased load — such as more users, data, or requests — without unacceptable performance degradation. It can be achieved in two main ways: It also includes operational, cost, and development scalability — how the system, budget, and team scale with g

Caches can exist on the client (OS or browser), on the server, or in a dedicated cache layer. Content delivery networks (CDNs) act as distributed caches to improve performance and availability. Reverse proxies and caching servers like Varnish can serve static and dynamic content directly. Web server