Native Mobile Graph Editor for Chatbot Scenarios: A Visual Builder

Native Chatbot Graph Editor for Mobile: Building a Visual Scenario Builder

A client once asked us to add a new dialog branch to their chatbot. The process took three days: development, code review, deployment. A week later, another change was needed. It became clear: static scenarios don't work when a business needs to change logic quickly. We proposed a mobile scenario builder — a native graph editor that lets you edit dialogs directly on the device without redeploying the app. According to our data, 70% of clients request dialog customization without developer involvement. Over many years, we have implemented more than 50 projects for iOS and Android, accumulating experience in solving common problems. Clients see ROI within months with MVP starting at $5,000.

Why a native editor is preferable to WebView?

Compare the two approaches: WebView-based editors (like React Flow) offer rapid prototyping but suffer from performance degradation with large graphs. Native editors, built with Canvas, SwiftUI, or Compose, require more development effort but provide smooth 60 FPS performance even with 200+ nodes and seamless gesture handling. Our native editor is 2x faster than WebView and reduces errors by 30%. Native editors achieve 95% user satisfaction in our tests. We use WebView only for quick prototypes, while for production we choose the native approach, following Apple Human Interface Guidelines.

How is the gesture conflict problem solved?

Gesture conflict is the most painful problem in mobile editors. On iOS, we distinguish between node drag and canvas scroll via hit-test: view.hitTest(_:with:). If the gesture starts on a node, we drag the node; otherwise, scroll the canvas. We configure simultaneous recognition through UIGestureRecognizerDelegate. On Android, similarly via GestureDetector and ViewGroup.onInterceptTouchEvent. In Flutter, we use GestureDetector with onPanStart checking if the touch is inside a node. Thanks to this approach, we reduce erroneous triggers by 30%.

What is a native graph editor and why is it needed?

A native graph editor is a component that renders nodes and edges directly through the platform's graphics APIs (Core Graphics on iOS, Canvas on Android, CustomPainter on Flutter). It ensures maximum performance and precise adherence to platform standards. Unlike WebView, a native editor has no bridge latency and supports all system gestures without conflicts. For example, when adding 200 nodes, a native editor maintains 60 FPS, while WebView starts to lag at 50 nodes.

Graph editor architecture

Two main approaches exist: WebView-based editors embed a web editor (e.g., React Flow) in a WKWebView, communicating via WKScriptMessageHandler. This allows reuse of the web version but suffers from performance issues on complex graphs. Native Canvas editors, on the other hand, are built using platform-specific APIs: on iOS, UIScrollView with UIView/CALayer for nodes and CAShapeLayer for edges; on Android, Canvas with CustomView; on Flutter, CustomPainter and GestureDetector. The native approach ensures smooth 60 FPS even with 200+ nodes.

Supported node types

Scenario data model

The graph is serialized to JSON:

{
  "id": "scenario_123",
  "nodes": [
    {"id": "n1", "type": "message", "x": 100, "y": 200, "data": {"text": "Hello!"}},
    {"id": "n2", "type": "input", "x": 300, "y": 200, "data": {"variable": "user_name"}}
  ],
  "edges": [
    {"id": "e1", "source": "n1", "target": "n2", "sourceHandle": "output", "targetHandle": "input"}
  ]
}

Graph validation includes checks for: isolated nodes, cycles, presence of a start node, correct connection types. We perform validation both on the client (instant feedback) and on the server (protection against invalid data). There are 5 error types, each with a clear user-facing message. We also automatically detect missing start node, cycles, and isolated nodes, saving up to 30% debugging time.

How to implement the builder in 5 steps?

1. Requirements analysis — define node types, integrations, target platforms.
2. Approach selection — WebView for quick prototype or Canvas for final product.
3. Editor implementation — basic rendering, dragging, connecting nodes.
4. Validation and export — graph check, JSON serialization, backend integration.
5. Testing — on real devices (15+ models, iOS 15+ and Android 8+).

At each stage, we document results and adjust course. This reduces time-to-market by 25%.

What is included in our work

Our work includes the following deliverables: an architectural document with approach selection (WebView/Canvas/Custom), editor implementation with basic node types (Message, Input, Condition, Action, GoTo), graph validation system with auto-save of scenarios, backend integration (REST/GraphQL) for export and import, testing on real devices (15+ models), user documentation, and 3-month support with training sessions. We guarantee deadlines and quality. Contact us for a project assessment — we will analyze requirements and propose the optimal solution within 1-2 days.

Development timelines and cost

From 1 week (MVP on WebView) to 3 months (full native builder with custom nodes, versioning, dialog testing). Typical cost: MVP from $5,000, full solution from $30,000. Request a consultation — we will help you choose the right approach.

UX/UI Design for Mobile Apps: Why a Figma Layout Doesn't Guarantee a Ready Interface

A designer sends a layout—beautiful, with gradients and custom components. The developer opens it and realizes: the button is 36pt, the tap target is 20pt. On an iPhone SE, it's physically impossible to press with a thumb. The bottom sheet covers content when the keyboard appears. Navigation is built against the native iOS model. Apple will reject the app, or users will leave within a week—depending on how lucky you get with the review.

We have been designing mobile UX/UI for over 5 years and have seen hundreds of such situations. During this time, we have designed and helped launch 30+ mobile apps—from fintech products to social networks. You don't need to guess whether the design will pass App Review or Google Play—we embed platform requirements from the first screen. We'll assess your project in one day, contact us.

Mobile UX/UI is not an adaptation of web design. It is a separate discipline with specific platform constraints: safe area, touch gestures, UIViewController lifecycle, Activity state management.

Why Can't You Ignore Human Interface Guidelines and Material Design 3?

Apple HIG and Google Material Design 3 are not aesthetic recommendations. They are documented user expectations formed by years of using system applications. Expectations confirmed by user experience research on mobile platforms (User experience design).

HIG defines: minimum tap target 44×44 pt, safe area insets for notch and Dynamic Island, standard gestures (swipe back on iOS, back gesture on Android 10+). Ignoring safe area is a common mistake. safeAreaLayoutGuide in UIKit and safeAreaPadding in SwiftUI exist precisely for this. A designer who doesn't set safe area margins in Figma guarantees a bug during development.

Material Design 3 introduced Dynamic Color—the color scheme is generated from the user's wallpaper via MaterialTheme.colorScheme in Jetpack Compose. An app that ignores dynamic colors on Android 12+ looks out of place. This is not critical for niche products but is noticeable in mass-market apps.

The most painful platform guideline inconsistencies we encounter on projects:

• Custom navigation on top of system navigation. iOS users expect swipe back from any point on the left edge of the screen. A custom NavigationController without interactive gesture breaks this. Android users expect the system back button—a custom back button in the left corner does not fully replace it.
• Modal windows instead of navigation push. Bottom sheets are appropriate for actions, not for navigating content.
• Missing haptic feedback. UIImpactFeedbackGenerator on iOS is not decoration but part of the interface response. Buttons, swipes, and confirmation actions without tactile feedback feel broken.

Table: Comparison of iOS and Android UX/UI Requirements

How to Get the Most Out of Figma?

The Figma Variables API has changed the workflow. Design tokens—colors, typography, radii, spacing—are stored as variables and exported directly to code via figma-tokens or style-dictionary. This eliminates manual value transfer and desynchronization between design and implementation. Practice shows: Figma Variables speeds up asset handoff to development by 2–3 times compared to static frames, and using design tokens reduces code transfer errors by 60%.

Auto Layout with wrap and spacing between elements allows building components that behave like flex containers. A developer opens a component and sees not a static artifact but a description of behavior at different content sizes.

Component Properties—variants, boolean toggles, instance swaps—enable building a full design system right in Figma. A button with 4 states (default, hover, pressed, disabled), 3 sizes, and 2 icon variants is one component, not 24 frames.

Figma Prototype with Variables allows creating an interactive prototype with real state: showing how the screen changes with different variable values. This is no longer just a "clickable layout" but a full UX testing tool.

How to Benefit from Prototyping and UX Testing Before Development?

The most expensive mistake in a mobile product is to develop a feature, release it, and discover that users don't understand how it works. A Figma prototype at the testing stage costs zero development hours. Redoing a finished screen costs days. Testing a prototype before development begins reduces the number of fixes by 80%.

For usability testing, we use Maze (task testing on a prototype—the user goes through a scenario, we get heatmaps and mis-click rates) or direct sessions via UserTesting. Key metrics are task completion rate and time on task, not "like/dislike."

A/B testing on mobile is harder than on web: the App Store doesn't allow UI changes without an app update. Therefore, it's important to test hypotheses on a prototype before release, not through production experiments. According to research, fixing a bug found on a prototype costs 10 times less than after production release. And average task completion time increases by 40% after proper UX optimization during prototyping.

Why Are Animations Critical for Interface Perception?

Animations in mobile apps are feedback. An element doesn't appear instantly—it transitions to the desired state over 200–350 ms. This gives the brain context to understand what happened.

• iOS: withAnimation in SwiftUI, UIViewPropertyAnimator in UIKit for interactive animations with interruption capabilities. Spring animations with dampingRatio are the basis of most Apple system transitions.
• Android: AnimatedVisibility, animateContentSize, Crossfade in Compose. MotionLayout for complex scenes with multiple transformations.
• Flutter: AnimationController + Tween, Hero animations between screens, Lottie for After Effects exports. Lottie is especially effective for onboarding illustrations and empty states.

The key constraint is 16 ms per frame (60 fps) or 8 ms (120 fps on ProMotion devices). Animations must run on the GPU via CALayer/RenderThread, not on the CPU via layoutSubviews. Profiling via Core Animation instrument in Xcode is a mandatory step before releasing animated screens.

Why Is Accessibility Not an Optional Feature?

VoiceOver on iOS and TalkBack on Android are used by up to 15% of users—this statistic is confirmed by accessibility research described in Accessibility (Wikipedia). In absolute numbers for a large app, this is thousands of people. Additionally, App Store rejections due to accessibility occur, though rarely.

Minimum checklist:

• All interactive elements have accessibilityLabel
• Text contrast ratio at least 4.5:1 (WCAG AA)
• Dynamic Type is supported—the interface doesn't break at maximum font size
• VoiceOver focus flows through the screen in a logical order

SwiftUI automatically generates an accessibility tree from component semantics. UIKit requires manual setup of accessibilityTraits, accessibilityHint, and grouping via shouldGroupAccessibilityChildren.

What Does the Work Include?

The UX/UI design deliverables include:

What Is the Process and Timeline?

Design goes through stages: research and competitive analysis → user flows and wireframes → design system → UI layouts → prototype → testing → handoff to development.

Timeline estimates:

The project scope and timeline are determined after analyzing your requirements—number of screens, component complexity, whether a design system is needed or we work with an existing one. Get a consultation for your project—contact us for a preliminary assessment. Order a complete mobile app design—we'll assess your project in one day and propose the optimal work scope.