Design and Build a Web or Mobile App

A Comprehensive Playbook

At FullStack, we have partnered with hundreds of mid-to-enterprise-size organizations, providing custom software development services to design and build their web apps, mobile apps, or app suites. In this playbook, you’ll learn the FullStack Labs methods for designing and building a custom application.

Phase 1

Pre-development Discovery

Laying the Groundwork for Innovation

In the discovery phase, we establish the bedrock of our collaborative journey, building a shared understanding and strategy for the successful development of your app. We aim to comprehensively grasp your envisioned application, discern your ambitions, and acknowledge potential hurdles. Through this, we strive to craft a tactical roadmap to transform your vision into a concrete, functional reality. This process typically includes:

Knowledge Transfer

We review existing data, prior research, and any foundational materials the client supplies. Before starting our app development journey, it is crucial to gain a thorough understanding of the landscape.

Stakeholder Conversations

Dialogues with primary stakeholders unearth crucial insights into their expectations, reservations, and the business rationale driving the app, informing a product that reflects and advances the company's broader goals.

Goal Setting

We pinpoint essential benchmarks encompassing technical prowess and business-oriented outcomes, such as user engagement, conversion rates, and revenue trajectories.

Market Analysis

A thorough competitive analysis allows us to assess the competition, recognize areas of opportunity, and differentiate ourselves to secure a unique market position for the mobile or web app.

Technical Discovery

Our technical discovery encompasses all backend and frontend considerations. We examine the tech stack, architecture, and integration possibilities to ensure a robust and scalable foundation for your custom app development. This process may include some proof-of-concept development to ensure feasibility.

Scope Definition

Here, we delineate what's in and what's out for your custom app. Determining the most important features for the MVP versus those that can wait ensures we avoid overreach and stay on track for a successful product launch.

Discovery provides clarity from the start.

Completing the pre-development discovery phase sets clear expectations for the feasibility and trajectory of the rest of the software development project. The discovery phase commonly includes delivering these items:

Key Deliverables

Phase 2

App Design

Crafting the Blueprint for User Engagement

In the design phase, your app comes to life, seamlessly blending form and function. We prioritize user experience and aesthetics, turning your custom mobile or web app vision into reality through wireframes, mockups, and prototypes. We aim to create an intuitive, engaging design aligned with your brand and goals.

User Experience (UX) Research

We examine user behaviors, needs, and motivations through various methodologies such as user interviews, usability testing, and persona development. This research informs design solutions that are not only visually pleasing but also highly functional and user-centric.

User Experience (UX) Design

Our team uses user feedback as our compass to guide the iterative process of refining the UX. We build the user's journey based on business goals and insights from UX research, crafting a seamless and intuitive navigation path. We leverage time-tested best practices, such as Jakob Nielsen's usability heuristics.

User Interface (UI) Design

Once we have the UX map, we create the interface. We carefully select aesthetically pleasing colors, typography, and imagery that communicate your brand's essence and engage your app's users. Our UI designers then create high-fidelity style concepts and development-ready mockups, which guide the developers when building the app interface.

Interactive Prototyping

Clickable prototypes are our testing ground, validating design assumptions and user flows. Interactive models help stakeholders and potential users provide feedback on the app, enabling us to iterate rapidly before any software code is written. These prototypes often show general app navigation, detailed interactions, and complex workflows.

Design System Creation

We build a comprehensive design system of reusable components and design standards to ensure consistency throughout the app and expedite future development efforts. Most of our clients customize an existing design system (such as Material Design) to meet their needs rather than build a custom app design system from scratch to save time and money.

Accessibility Design

Accessibility isn't an afterthought; it's embedded in our app design process. We ensure that the app is usable by everyone and complies with ADA standards and other regulatory requirements. By designing with inclusivity in mind, we create experiences catering to a diverse user base, expanding your reach and fostering a positive brand reputation.

Software design brings your plan to life.

The design phase brings life to the product requirements. It progresses the application to a state where it can be evaluated by stakeholders, tested with users, and ultimately built by the development team. (For more details, review our Designing a New App Playbook) Common deliverables of a design phase include:

Key Deliverables

Learn more about Product Design

Phase 3

App Development

Quality Code, Built with Speed

In the app development phase, your app becomes a reality, turning the strategic plans and designs into a functional, dynamic product. Our experienced developers and specialists work efficiently to translate your vision into code, ensuring smooth project progression and timely deliveries. This phase makes up the most significant part of our overall software development process and typically includes:

Pre-development Planning

Before writing a single line of code, we plan each stage of development. This includes assembling a skilled app development team, completing design-to-development handoffs, establishing key project milestones, and outlining sprints and stories for efficient progress.

Design-to-dev Handoff

A smooth handoff process is critical for seamless development. We ensure software developers receive all the materials from the design phase, including user personas, flow maps, style guides, high-fidelity designs, and clickable prototypes.

Assemble the Team

Our typical software development team includes two senior developers, a project manager, a quality assurance expert, a part-time designer, and a product owner. This combination of onshore and nearshore development professionals ensures a balance of expertise and perspectives.

Establish Development Milestones

We set project milestones, referred to as version releases, at regular intervals to ensure steady progress. These milestones include a limited number of app features for client testing and feedback.

Create Stories

Stories are tickets that define what the app developers need to build within each epic and how each feature should perform to meet quality assurance standards. These stories guide our development process and maintain clarity throughout the project.

Sprint Planning

Stories are organized into two-week sprints for focused development. We plan multiple sprints at the outset, providing flexibility and precision in early sprints and adaptability in later stages, and continue our sprint planning throughout the engagement.

Active Development

With thorough planning complete, we launch into active software development, executing sprints and launching version releases per the established milestones.

Sprint Execution

Developers work through stories in each sprint, ensuring all tasks are clearly outlined with links to necessary assets and acceptance criteria.

Test Coverage

We emphasize strong test coverage from day one, including automated unit and integration tests. This approach alerts us to potential issues early on and saves time and resources in the long run.

Quality Assurance

Quality assurance checks the app's code against acceptance criteria, ensuring compatibility across devices and browsers while upholding mobile responsiveness. This is critical to successful custom software development and ensures user acceptance.

Code Review & Merge to Master

The code undergoes a thorough quality review before merging with the master codebase. We adhere to our code quality standards, ensuring clean, concise, and maintainable code.

Sprint Retrospective

At the end of each sprint, our team conducts a retrospective to assess progress, identify any issues, and adjust plans as needed. This iterative feedback loop enhances efficiency and keeps the custom software development project on track.

Version Releases

Completed sprints culminate in version releases that allow clients to test features and provide feedback, ensuring your custom app meets your requirements and exceeds expectations.

Web and Mobile App Development with Unmatched Code Quality

During the development phase, your team will begin seeing early releases of the app. This will allow you to ensure the dev work is going according to plan. When the development phase is complete, your app is ready for launch.

Learn more about Custom Software Development

Phase 4


Mission Control: We’re Ready to Launch

The launch phase is the culmination of the custom software development process, where your app is introduced to the world. This phase involves thorough testing and refinement to ensure a successful launch that exceeds user expectations. We work hand in hand with you to guarantee that the launch process is efficient and coordinated and sets the stage for future growth. Most applications include:

Beta Testing

Beta testing is a critical phase where a select group of users puts your app through real-world usage, allowing us to identify any last-minute issues and fine-tune the app for an optimal launch. This testing period ensures that the app is stable, user-friendly, and ready for a successful public release.

Private Beta

We begin with a private beta testing phase, providing access to an identified group of users to gather real-world feedback and identify any remaining issues. This helps us fine-tune the web or mobile app before it is open to public testers.

Public Beta

After addressing feedback from private beta testers, we open the app to a wider audience in the public beta phase. This broader testing helps us gather diverse insights and further validate the app’s functionality, stability, and user experience.

Public Release

The custom app is now ready for its public debut. At this stage, our primary focus is facilitating a seamless and successful launch, positioning your business for success from the outset.

Final Preparations

Before the official public release, we conduct final checks to ensure all elements, including user documentation, support resources, and marketing materials, are in place.

Launch Day Coordination

Our team works alongside you to coordinate a seamless launch day, managing timelines and ensuring the app is available on the appropriate platforms at the scheduled time.

Post-Launch Monitoring

Once your app is live, we closely monitor its performance and user engagement. We stay alert for any potential issues and address them promptly to guarantee a positive user experience.

Feedback & Iteration

We gather user feedback post-launch to identify areas for improvement and new opportunities. This ongoing iteration process keeps your app fresh and responsive to user needs.

Launch your app into the world.

With strategic launch planning and execution, you can have confidence that your users will experience a stable version of your app.

Phase 5


Keeping Your App Running Smoothly and Securely

The maintenance phase marks the beginning of your app's post-launch lifecycle, where our focus shifts from development to ongoing support and optimization. During this phase, we establish a maintenance agreement tailored to your needs: basic upkeep, routine updates, or continued feature development. This agreement ensures your custom app remains secure, functional, and competitive over time.

Maintenance Agreement

For applications with limited planned future development, a maintenance agreement is all that's required to keep the app running well. Maintenance may cover the following:

Error Monitoring & Bug Reporting

We utilize various third-party tools for error monitoring and bug reporting, such as CodeClimate, ESLint, Sentry, and Bugsnag. These tools notify us when issues arise and help optimize performance.

Update Versions

Open-source software languages are continuously updated by the open-source community. Each update is known as a "version." It's crucial to keep versions up-to-date to ensure performance and security. Therefore, our maintenance agreements include updating versions as a standard deliverable.

Performance Optimization

For applications that handle large amounts of data or have substantial user bases, ongoing performance optimization may be necessary. This may include monitoring and optimizing servers, load testing and optimization, and crash reporting and response.

Update Integrations & Dependencies

Modern applications are built with various third-party dependencies and APIs, which can evolve. Updating applications to ensure they continue to integrate seamlessly with third-party dependencies is a crucial part of our maintenance agreements.

Compliance and Security

We ensure your custom mobile or web app adheres to industry standards and regulatory requirements, providing updates as needed to maintain compliance and protect user data.

Documentation and Training

We provide comprehensive documentation and training to empower your team to manage the app effectively and understand any new features or updates.

Ongoing Development

For clients who wish to continue adding features and making changes to their custom app over time, an ongoing development agreement will be needed, in addition to a maintenance agreement. Ongoing development agreements include the following:

Product Roadmaps

We'll work with your team to create a robust product roadmap that outlines which new features will be built and when. This helps prioritize features, plan budgets, and more.

Design New Features

After adding new features to the product roadmap, we'll complete a design process to demonstrate the new feature and how it will operate within the existing application.

Develop New Features

Once the design is complete, we'll estimate how much time will be required to develop the new app feature, then will add it to an upcoming sprint to be completed.

Maintain what you’ve built.

At FullStack Labs, we can provide an ongoing maintenance agreement that meets your needs and allows you to meet your business goals.

Design and Build a Custom Web or Mobile App with FullStack Labs

Launching custom software is a complicated process with several moving pieces, each with a high complexity level. Partner with FullStack Labs, a custom software development company with proven experience in launching successful apps.

Transparent Collaboration

Our approach is flexible to accommodate each client's preferences. Whether you prefer to be closely involved or get periodic updates, we ensure clear and consistent communication.

Full-Service Excellence

With our team’s diverse skill sets, FullStack Labs is your ideal choice for a full-service app development company. Partner with us to begin your next digital transformation.

Are you ready to build your next app? Contact our experts at FullStack Labs and take the first step today.

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