Architecture

Introduction  Behind every successful software, there is a well-structured and meticulously executed Application Development Life Cycle (ADLC). ADLC breathes life into ideas, transforms them into robust applications, and guides them through a journey of growth and evolution. From inception to deployment, this systematic approach paves the way for efficient planning, precise coding, rigorous testing, and continuous improvement. Join us as we unravel the mysteries of the ADLC and unlock the key to building scalable applications to reshape the future of the digital landscape.  What is Application Development Life Cycle (ADLC)? ADLC, also known as software development life cycle (SDLC), is a step-by-step process that takes an app idea and transforms it into a fully functional and user-friendly application. It involves planning, designing, coding, testing, deploying, and maintaining the app to ensure its success and continuous improvement. Application Development Life Cycle (ADLC) is essential for creating high-quality and successful applications. It allows developers and stakeholders to carefully plan and define the app’s goals, features, and user experience. It also ensures that everyone involved in the process has a clear understanding of what the app aims to achieve. Six Phases of ADLC The Application Development Life Cycle typically consists of six phases that play a crucial role in every digital product development.  1. Project Discovery  The project discovery phase in the Application Development Life Cycle is an essential stage where project requirements are gathered and analysed. It involves conducting research, meeting with stakeholders, and understanding the project’s purpose, scope, and desired outcomes. This phase sets the foundation for successful planning and execution of the development process by identifying project constraints, goals, and feasibility. Through thorough discovery, the project team gains valuable insights to ensure a clear understanding of project needs before proceeding to subsequent phases. 2. PlanningThe planning phase in the ADLC is a crucial stage where the project’s roadmap is outlined and project goals are defined. During this phase, the project team creates a detailed project plan, establishes timelines, allocates resources, and determines the project scope & success criteria. They identify risks, dependencies, and constraints that might impact the development process and devise strategies to mitigate them.The planning phase sets the foundation for efficient project execution by providing a clear direction and ensuring all stakeholders are aligned with the project objectives. It helps in estimating costs, organising tasks, and establishing communication channels, ultimately facilitating a smooth transition into the subsequent software development cycle. 3. DesignThe design phase in the Software Development Life Cycle is a critical stage where the visual and functional aspects of the application are defined. In this phase, the software project team creates the user interface (UI) and user experience (UX) design of the application. They determine the layout, navigation, and overall look and feel of the app.The design phase involves wireframing, prototyping, and iterating on the design based on user feedback. The goal is to create an intuitive and visually appealing interface that enhances usability and provides a positive user experience. This phase sets the foundation for the development and guides developers in implementing the envisioned design. 4. DevelopmentThe development phase in the ADLC is a core stage where the actual coding and programming of the application take place. During this phase, developers write the code that brings the design and functionality of the application to life. They follow the requirements and specifications gathered in earlier phases, utilising programming languages, frameworks, and tools to create the desired features and functionalities.The development phase involves writing clean, efficient, and modular code, adhering to coding standards and best practices. Developers collaborate, review each other’s code, and integrate different components to ensure a cohesive and functioning application. This phase lays the groundwork for subsequent testing and deployment phases. 5. Quality Assurance (QA)In the Quality Assurance phase, the application is thoroughly tested to ensure its functionality, reliability, and performance. QA engineers and testers employ various testing techniques, such as unit testing, integration testing, system testing, and user acceptance testing. They identify and document any defects or bugs in the application, ensuring they are addressed and fixed before deployment. The QA phase aims to verify that the application meets the specified requirements, performs as intended, and delivers a positive user experience. Rigorous testing during this phase helps ensure the application’s quality and helps in delivering a robust and error-free final product. 6. Deployment The deployment phase marks the stage where the application is prepared and made available for actual use. It involves the final steps required to release the application to the intended users or customers.The deployment process includes tasks such as configuring servers, setting up databases, establishing network connections, and installing the application on the targeted platforms or devices. It also involves finalising documentation, user guides, and support materials. The deployment phase ensures that the application is properly installed and accessible to users, ready to deliver its intended functionality and value in a live production environment. 7. Maintenance & SupportThe maintenance phase occurs after the application has been deployed and is in active use by users. During this phase, developers and support teams monitor the application’s performance, address any reported issues or bugs, and make necessary updates or enhancements.The maintenance phase includes regular system updates, security patches, and bug fixes to ensure the application remains secure, stable, and compatible with evolving technologies. It also involves incorporating user feedback, analysing usage data, and implementing continuous improvements to enhance the application’s functionality, performance, and user experience. The maintenance phase ensures the long-term success and reliability of the application in a production environment.Note: It’s important to note that the specific phases and their names may vary depending on the development methodology used (e.g., Waterfall, Agile, etc.), but the general concepts of planning, designing, developing, testing, deploying, and maintaining an application remain consistent across most ADLC frameworks. ADLC Models There are several Application Development Life Cycle models, each with its own approach to managing the software development cycle. Here are four common ADLC models with examples: 1. Waterfall ModelThe Waterfall model works with a linear and sequential approach. Each phase is completed

Introduction  As a software product owner or an architect, you may have found yourself caught in a situation where you need to migrate your legacy system to a modern system, but unfortunately, the migration can be lengthy and time-consuming. So you may have been tasked to carry out the migration gradually over a period of time, thus ensuring that the new application should be able to utilise the legacy resources such as data. More often than not, your legacy system may have issues due to which it is not able to perform well to cater to your present needs. For instance, your legacy system database is too complex with very tight relationships that need to be broken down to support your modern cloud architecture pattern. Maybe the legacy APIs are obsolete and your modern system requires new APIs and frameworks. To support the smooth transitioning from the legacy system to the modern system, your systems need to interoperate. Hence, maintaining access between new and legacy systems can force the new system to adhere to at least some of the legacy system’s APIs or other semantics. So the problem is the potential corruption of your modern clean architecture in order to support the legacy system/features. A similar problem arises when dealing with external 3rd party systems. To support the smooth transitioning from the legacy system to the modern system, your systems need to interoperate. Hence, maintaining access between new and legacy systems can force the new system to adhere to at least some of the legacy system’s APIs or other semantics. So the problem is the potential corruption of your modern clean architecture in order to support the legacy system/features. A similar problem arises when dealing with external 3rd party systems. The solution I am about to explain is called the Anti-Corruption Layer Pattern. But before I move forward and talk about it in detail, I want to establish the fact that this solution needs to be considered in the following scenarios: Also, note that this pattern may not be suitable if there are no significant semantic differences between new and legacy systems. Solution The solution is building an adapter layer or an anti-corruption layer between the two systems. In essence, this layer translates communication between your legacy system and your modern system acting as a gateway. This allows legacy systems to be unchanged and yet at the same time makes sure that your modern system design stays uncompromised. A good scenario could be thought out to be as your legacy system is a monolithic architecture that was designed some years ago to support the business requirements back then. But your modern architecture and AWS design pattern is a service-oriented architecture and supports different applications. Some services need access to legacy functions during the migration stages for interoperability and business continuity. Now that you’re aware of the significance of data security in safeguarding your business against potential data breaches, let’s delve into what data security entails and how it can be beneficial for you. The design for such an anti-corruption layer is simple but may add a certain level of complexity per use case basis. Some of the design considerations when architecting such an anti-corruption design pattern could be: Also, note that this pattern may not be suitable if there are no significant semantic differences between new and legacy systems. Similarly, there could be more design considerations and factors that you may need to consider if you are planning to retire your legacy system to a more advanced modern system and are not sure about how to go about it. Conclusion  Are you facing the challenge of migrating your legacy software to a modern architecture? Don’t let the migration process overwhelm you. Trust The Nth Bit Labs for a smooth and successful transition. Our Anti-Corruption Layer Pattern expertise ensures your legacy systems remain intact. Take the first step towards modernizing your software with confidence.

Introduction  API Gateways; it seems to have become a hot buzzword that often gets tossed around in discussions about building robust and scalable tech products. But you are not alone if you do not fully understand what it means, how it contributes to the strength and scalability of your B2B or B2C software product, and how you can actually benefit from it. What is an API Gateway? API gateway is a design pattern that works like a middleman between API endpoints and backend services. It receives the Client’s API requests, aggregates them, and then routes them to the required service endpoints. When a client initiates an API request, the API Gateway steps in, consolidating and managing these requests before efficiently directing them to the specific service endpoints they require. To support the smooth transitioning from the legacy system to the modern system, your systems need to interoperate. Hence, maintaining access between new and legacy systems can force the new system to adhere to at least some of the legacy system’s APIs or other semantics. So the problem is the potential corruption of your modern clean architecture in order to support the legacy system/features. A similar problem arises when dealing with external 3rd party systems. In short, the API Gateway acts as a vital link, optimizing the flow of data between clients and backend services, contributing to a more organized, responsive, and streamlined operation of digital systems. Use Cases of API Gateways Whether you are building a B2B or a B2C SaaS product, API Gateways can be the game-changer for your business. After reading the use cases of API gateway you’ll know how it enhances both the performance and security of your software. 1. Caching API gateways store the data of request responses for reuse later. It not only enhances the performance of the server but also reduces the load on back-end services. If it receives similar requests earlier, it sends the response from the cache itself rather than back-end services. Imagine you have a favorite online game. Instead of fetching the latest game updates every time you play, the API gateway stores a copy (cache) of the updates. So, when you want to play again, it quickly gives you the stored updates, reducing the time and resources needed to fetch them anew. 2. Aggregation Think of your phone displaying news from various sources in one app. An API gateway aggregates information from different sources and presents it in a unified way. It is a unified point for clients to access various service points. In this, one gateway receives and handles all the requests and routes them to its respective backend service. It’s like having one app that combines news, weather, and social media updates seamlessly. 3. Request Routing In a system with multiple services, the gateway guides requests to the appropriate service, ensuring they reach the right destination efficiently. Let’s understand request routing with an example. Picture ordering food online. The API gateway directs your order request to the correct restaurant’s kitchen that you have actually ordered from. 4. Rate Limiting and Throttling Rate limiting is a method that is used to limit the number of requests a user can make in a given period. While throttling refers to a technique that controls the load of traffic an API can handle and prevents overloading the server at once. Still confused? Let’s clear this up with an example.Suppose you’re at an ‘All-You-Can-Eat’ buffet. To make sure everyone gets a fair share, the restaurant sets limits on how fast you can fill your plate. API gateways do something similar; they control the rate at which requests are made to prevent overload or abuse, ensuring fair access for everyone. 5. Authorization and Authentication Just like you need a pass to enter the VIP lounge at an event, API gateways use authentication and authorization permission from the user to access the services. API gateways ensure that only authorized users (with proper access credentials) can use certain parts of a system, just like the VIP lounge is restricted to specific guests. When using methods like OAuth or JWT, the API Gateway may issue and validate tokens. These tokens carry information about the authenticated user and are used to grant access. Common API Gateway Patterns Choosing the right API gateway pattern is pivotal for designing a successful software product. Each pattern comes with distinct advantages, addressing specific needs within the system. Here are some API gateway patterns you should consider while designing your APIs. Centralized Edge Gateway A centralized edge gateway in API gateway patterns is a design where a single, centralized point manages and controls external API requests. This gateway acts as the entry point for all requests, providing a unified location for enforcing security measures, authentication, and access control.
The Centralized Edge Gateway ensures consistency and simplicity in managing client requests. It is an effective choice for businesses seeking centralized control over their API ecosystem while maintaining a secure and streamlined communication channel. Microgateway A Microgateway in API gateway patterns is tailored for microservices architecture , providing individualized control over each service. It means every microservices has its own API gateway. Unlike a centralized gateway, the Microgateway allows for independent scaling and maintenance of microservices. This pattern ensures flexibility and agility in dynamic systems where services evolve independently. It optimizes communication efficiency, offering a decentralized approach to managing APIs. The Microgateway pattern is particularly advantageous in environments where adaptability, scalability, and autonomy of microservices are crucial for maintaining a responsive and evolving system. Per Pod Gateway In the per-pod gateway pattern, the dedicated API gateway for each pod serves as an intermediary between the clients and the services running within the pod. This gateway acts as a reverse proxy, managing the routing of requests from clients to the appropriate services and forwarding the responses back to the clientsThe primary advantage of the per-pod gateway pattern is the level of isolation and autonomy it provides to each pod. By having a dedicated gateway for each pod, there is