This guide serves as a comprehensive framework for engineering excellence, outlining essential system design and architectural principles tailored for Bandpey. It is curated as a dynamic repository, providing a wealth of resources aimed at enabling our clients to develop scalable software solutions effectively. Through these guidelines, we commit to fostering innovation, ensuring best practices, and facilitating the creation of robust, scalable systems that meet the evolving needs of our customers.
Every software system has a structure, whether that structure is meticulously planned or evolves in a chaotic manner. The longer we spend building a software system, the more challenging it becomes to alter its architecture down the line. This architecture not only defines the system's purpose and its operational quality but also deeply influences its performance and scalability, the ease of integrating new features, and its resilience against failures and security breaches. A suboptimal organization of our software can lead to steep costs for redesigns. Too many software projects start as proof of concepts (PoCs) without a forward-thinking architectural plan, setting the stage for a host of problems. It's high time we recognize that neglecting the architecture of our software in the early stages can corner us into expensive and time-consuming overhauls later on. Let's not fall into that trap.
Software architecture is essentially a blueprint of a system. It sketches out the high-level structure, pinpointing various components and detailing how they interact to meet the system's requirements and constraints. Think of it as the skeleton of a building, outlining its essential support structure without getting bogged down in the specifics of which brand of nails or screws are used.
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High-level Design (HLD): By high-level, we mean it's an abstraction layer that highlights the key components and their interactions, deliberately ignoring the nitty-gritty of implementation. It’s like looking at a map; you see the cities and the highways connecting them, not every house or streetlight.
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Tech specifics: Normally, you won’t find details like which programming languages or technologies are used, or the nitty-gritty of API calls in the HLD. Those are reserved for the low-level design, which dives into the implementation details.
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Purpose of HLD: The idea behind keeping the design high-level initially is to postpone locking in on specific technologies for as long as possible. This gives us flexibility and ensures that our choices are guided by the system's actual needs rather than a premature commitment to a particular stack.
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Components: In software architecture, components are like black boxes defined by what they do (their behavior) and how they talk to other components (their APIs). These components might be complex systems in their own right, each with its own HLD and Low-Level Design (LLD).
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Integration and Constraints: The HLD should make clear not only how these components fit together to fulfill the system's functional requirements but also outline what the system does not or should not do, marking the project's boundaries and limitations.
By focusing on the high-level design early on, we create a solid foundation that guides the development process, ensuring that when it comes time to make detailed decisions, they’re informed by a clear understanding of the system as a whole, not just immediate needs or current preferences.
In the architecture of software systems, we deal with multiple layers of abstraction.
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Lowest Level: At the ground floor, we're talking about classes, functions, and the nitty-gritty of object interactions, all shaped by the choice of programming language. It's here where the micro details of coding practices live.
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Mid-Level: Moving up, we encounter modules, packages, and libraries, along with the rules of engagement for how these elements interact. It's a bit like organizing departments within a company so they communicate and collaborate efficiently.
Modern software architecture tends to zoom out from these granular details. The shift towards agile development means lengthy upfront design phases clash with the need for speed and flexibility. Instead of meticulously planning every class and function, we enforce structure through coding guidelines, DevOps practices, linting, and code reviews. It's less about drafting every detail on paper and more about setting up a system that guides developers towards best practices.
- High-Level Abstraction: For large-scale systems, our focus shifts to an even broader view: services and how they interact in a distributed, multi-service ecosystem. Here, components are entire processes or groups of processes, potentially running on different machines. This approach equips us to build systems capable of handling immense loads, processing and storing vast amounts of data, and serving millions of users daily. Think ride-sharing apps, video games, investment platforms, social media, and so on.
Getting the architecture "future-proof" means scaling from a small proof of concept (PoC) or minimum viable product (MVP) to a fully-fledged product without needing to overhaul everything. A well-thought-out design can save months of engineering effort, avoid building a system that falls short of requirements, and prevent the costly process of re-architecting a system bogged down by years of technical debt. The stakes couldn't be higher: nail the architecture, and you pave the way for scalable, robust development; miss the mark, and you're looking at significant setbacks.
Software development typically unfolds across four main phases: design, implementation, testing, and deployment. These phases are not linear; they are part of an iterative process that often requires going back and refining previous steps. Initially, this cycle produces a prototype, and subsequent iterations refine and expand upon the existing system, as illustrated in the diagram below.
In this context, software architecture forms during the design phase and serves as a foundational blueprint for the implementation phase. Throughout this document, we focus primarily on the design phase, which explains why terms like "software architecture" and "system design" are used interchangeably here.
It’s important to note that software architecture isn’t about achieving perfection on the first try. Instead, it's about adopting a systematic approach to evolve the system. This involves leveraging industry best practices and established design patterns to guide development, ensuring the architecture can adapt and improve over time.