What is the best way to document architecture for mobile applications?

Architecture should be documented at early stages as it helps to brainstorm the requirements and find the best ways to implement them, identifying any potential problems like design issues, future risks and helps to proactively address them at the early stages of planning instead of identifying them in development/testing phases. It serves as a blueprint for all the stakeholders and as a reference after project completion so it's essential to keep it updated whenever there is a new requirement update.

If you application - not just mobile: any custom-built application - is not documented, it means that you/your colleagues/your successor will waste hours or even days trying to understand how it works. You/they will have to dig into the code, build a mental map of all the code & data elements that make up the application + all their dependencies.

If you're a visual thinker, you'll need very little persuasion to create some high level diagrams as a way to capture and rationalize your approach. In addition, those of us in heavily regulated industries need very little encouragement to create some level of architecture documentation - as it is simply required and auditable. However, another consideration - beyond software engineering best practice - is what happens when your development team extends beyond 1 to 2 people (or 1 to 2 time zones). How do you effectively collaborate early on - when every one has their own vision of how the system might be composed? Architecture documentation at various levels is one of the easiest ways to get everyone aligned.

Documenting architecture makes you thoroughly think about it. You will catch hidden details sooner, even before you started implementing them with your team. It also lets you see clear progress that you are making with every sprint, every release, because as the application is getting bigger, some little things in the architecture may, or sometimes surely will, change as well.

Documenting mobile app architecture is crucial for team understanding. Start with a high-level overview and architectural pattern explanation. Use code comments, class, and sequence diagrams to clarify complex parts. Detail component roles and data flow. Document dependencies and integration with external systems. Version control your docs and include README files. Define coding style guidelines and future maintenance plans. Encourage team collaboration and use documentation tools for efficiency. Effective architecture documentation ensures smoother development and scalability.

In my experience, documenting the architecture for mobile applications is crucial for ensuring the clarity, maintainability, and scalability of the project. Here are important considerations when documenting mobile app architecture: Main features, System Overview, Architectural Diagrams, Key Components, Technology Stack, Data Flow, User Interface (UI), Authentication and Security, Data Storage, Networking, Concurrency and Multithreading, Performance Considerations, Error Handling and Logging, Testing and Quality Assurance, Deployment and Release, Scalability and Future Considerations, Dependencies and Third-Party Libraries, Maintenance and Support.

DOCUMENT EVERYTHING. - Create an architectural diagram on your favorite canvas for the MVP. - Document the inter-communication of each module of the architecture - For each PRD, create a design doc to answer the how, why, what, and where. Encouraging collaboration on such documents is a must. - Have a special place to document special features (like a core algorithm that drives your product) and explain it thoroughly.

The code is the document. Documents go stale. So keep it very high level indeed. Just a topology diagram with core themes. Let the code do the rest.

As much as you can! - High-level overview: A bird's-eye view of the application. - Architectural style and patterns: Design principles guiding the app. - Major components and modules: Their functionalities and interrelationships. - Key technologies: Tools and tech stacks used in development. - Deployment strategy: How the app is rolled out to users. - Distribution model: Platforms and methods of distribution. - Non-functional requirements: Performance, security, and other quality attributes. - Constraints: Limitations or conditions influencing the app's design.

According to my experience in Web Development, Frontend Architecture, Backend Architecture, Used Libraries, Business Logic, Components Structure, Files/Folders Structure, Database Style, are the essential components to include in Documentation.

Diagram as much as you can. It clarifies things to people from all tech frameworks, and opens up to any flow-flaws. The best part is: anyone can pick out problems in a diagram, you don’t need to know the framework. After diagrams, the standard & practices need to be penned down to make sure architecture is followed.

Documenting mobile app architecture requires a blend of visual aids and detailed descriptions. UML offers a standardized way to visualize system components, but its depth might be overwhelming for some stakeholders. The C4 model, with its hierarchical approach, allows teams to zoom in and out of details, making it versatile for varied audiences. ADRs, on the other hand, focus on the 'why' behind architectural choices, ensuring that decisions are well-understood and traceable. . The key is to combine these methods, tailoring documentation to the project's needs and the audience's familiarity with the system.

Frontend, Backend Architecture, Folder Structures, Components Structure can be maintained in documentation in just doc file and using some examples. And Database Logic must be documented using different ER-Diagrams, or Class Daigrams in the case of OOP

Best method to document a custom-built software is to have a machine do it for you (yes, it is possible!). Machine-generated technical documentation is produced by software intelligence technologies, like CAST Imaging. They automatically analyze and understand how any custom-built software works via semantic analysis of database scripts, source code, config & property files, etc. The output of this reverse-engineering exercice is an interactive, navigable, searchable application blueprint, which is accurate, extensive, and up to date.

After reviewing a lot of tools, my personal choice is the C4-PlantUML library. It provides out-of-the-box a lot of components that will enable you to quickly write the code of your architecture diagram. After combining the .puml definition with proper GitHub Actions workflow, you end up with an automated solution, and thanks to VCS you can quickly navigate through the changes and include the pull requests to the documentation into the definition of done for any architectural change.

In my experience documenting each sprint is important when you are working in a startup company. You architecture may have additional modules as you grow, some additional requests by your end users, and the way you handle them and the way your architecture is capable of handling them, sure should be documented. Startups tend to focus on speed, so implementing and thinking architecture thoroughly in the beginning is not always the case. Therefore your architecture will surely change over time. Document each sprint, and you will see how much time that will save you in the future.

Document whenever you are about to begin a feature, then make tweaks after you are done with the feature. This will give you a general understanding of the business needs, impact, and technical assessment before starting the feature, and the correctness of the document when you have tweaked the code base, after the feature. This entire process saves a lot of time.

It depends on what SDLC you are working with, if it's the case of Agile then you should document in each sprint, and also in everyday scrum's(in the case of new introductory logic). Documenting in each sprint, will save so much of time and leads to efficient softwares!

The timing of documentation is important, starting early, during the design phase, sets a clear roadmap. However, as development progresses, changes and refinements should be continuously captured. This "document as you go" approach ensures real-time accuracy. It's also crucial to strike a balance: over-documenting can be as detrimental as under-documenting. Tailoring the content to the audience's technical proficiency ensures relevance. Regular feedback loops with stakeholders keep the documentation aligned with evolving needs. In essence, treat documentation as a dynamic entity, evolving in tandem with the application's lifecycle.

Most documents will thrive when they are treated like live documents which are constantly modified based on new information (the exception being the ADRs, as they are records of decisions). So document early, but also maintain them when anything changes.

Effective communication of an app's architecture is about fostering understanding and collaboration. Presentations and demos offer visual insights, making complex architectures digestible. Workshops allow for interactive discussions, bridging gaps between technical and non-technical stakeholders. Wikis, confluence, stoplight doc serve as accessible, continuously updated resources, while code reviews and pair programming immerse team members directly into the architectural nuances. The key is adaptability: understanding your audience and choosing the right medium. By ensuring stakeholders not only see the architecture but truly grasp it, you pave the way for informed feedback, cohesive development.

Communicate actively, be clear and empathetic, provide feedback, consider nonverbal cues, choose appropriate mediums, stay open-minded, be brief, ask questions, and use visuals when needed.

For communication on such documents, I have found that it is best that the diagrams from your notebook should be drawn on draw.io and then added to the document. Google Docs is a great collaboration tool where people can easily review your document and leave insightful comments. The documents can also be formally approved/rejected. Once your document is ready, you can ask for the stakeholders to review it.

When there isn't enough time for comprehensive documentation, introduce an easy-to-apply approach - use case or problem statement, Q&A, and decision log. Invite stakeholders for a review.

If you are doing native apps, it's pretty easy to document because most of the time you are using Model View ViewModel (MVVM) architecture. If there are micro-services, then usually you will add it in the ViewModel. If you are not doing native apps, then your architecture will follow any responsive design website. There isn't a "mobile application" architecture. It's just documenting your application's architecture. Mobile or not doesn't make a difference.