Developing a product catalog with filters for a mobile app is a challenge we have tackled in over 80 projects, serving clients from fashion retail to building materials. A properly implemented catalog not only displays products but also helps users quickly find the right item through filters, sorting, and switching between grid and list views. We guarantee performance even with 10,000+ SKUs and complex display logic.
The most common mistake when creating a catalog is storing filter state in the component's local state. When navigating to a product card and back, all selected parameters are reset, forcing the user to start over. According to our observations, this reduces conversion by 15–20%. Our approach: filters are stored in a global store (Zustand, Redux, Riverpod, or Bloc) and serialized into a deep link to preserve between sessions, which works more reliably than simple session state.
List performance is the second key quality criterion for a catalog. FlashList from Shopify renders long lists 5–10 times faster than the standard FlatList when dealing with 1,000+ items. FlashList — Shopify Open Source confirms that replacing FlatList with FlashList reduces time to first frame by 58–70%. On Flutter, we use CustomScrollView with SliverList and virtualization. Product images are cached via FastImage (React Native) or CachedNetworkImage (Flutter) — traffic is reduced by 40–60%.
How to Structure Filter Architecture in a Mobile App?
Filters are divided into two types: client-side (applied instantly to already loaded data) and server-side (a request is sent to the backend on each change). Client-side filters are faster and require no network requests, but are limited by the amount of data on the device. Server-side filters are necessary for catalogs with thousands of items or complex business logic: real-time warehouse stock, contractual pricing.
We implement a hybrid approach: the first page loads from the server with default parameters, subsequent pages are updated via a debounced request (300 ms) when filters change. State is serialized into URL through react-navigation or go_router, allowing users to return to the catalog with the same settings even after app restart. Users can also share a link to a specific product selection — more convenient than storing only in the device's RAM.
Which Product Catalog View Modes to Choose?
Most eCommerce apps support grid and list views. Grid is better for visual products — clothing, furniture, decor — where the buyer chooses by sight. List is more convenient for electronics or auto parts, where specifications and price matter. We recommend supporting both modes and saving the user's choice in AsyncStorage (React Native) or SharedPreferences (Android) so it persists between sessions.
| Parameter |
Grid |
List |
| Columns |
2–3 |
1 |
| Display focus |
Image, price |
Description, specifications |
| Application |
Clothing, decor, cosmetics |
Electronics, parts, materials |
| Scroll speed |
Fast scrolling |
More information per screen |
| Recommended type |
Impulse purchases |
Rational choice |
Performance Optimization and Technical Solutions
For smooth scrolling, memoize the product card component and separate images into preview and detail views. Pagination is built using onEndReached (React Native) or ScrollController (Flutter): when 80% of the list length is reached, the next page request is sent in advance. This makes data loading unnoticeable to the user. This approach is faster than a manual "Show more" button and more efficient than preloading all pages.
Four steps to reduce list render time:
- Replace FlatList with FlashList or use SliverList on Flutter instead of ListView.builder
- Add card memoization via React.memo or const-constructor widget
- Set up getItemType for different cell types: product, banner, separator, skeleton
- Enable removeClippedSubviews and adjust windowSize to the device screen size
| Metric |
Before Optimization |
After Optimization |
| FPS when scrolling 1,000 items |
30–40 |
58–60 |
| First paint time, ms |
800–1,200 |
200–400 |
| Memory consumption, MB |
180–250 |
80–120 |
| Image traffic |
100% |
40–60% |
Typical mistake: filters in component local state
When storing selected filters in useState (React Native) or StatefulWidget (Flutter), the component loses state on navigating back. The user has to reconfigure filters — according to our data, this reduces conversion by 15–25%. Solution: move filters to a global store and serialize into URL via deep link. State restoration takes less than 50 ms and is unnoticeable to the user.
What's Included in the Work
- Catalog UI: grid, list, product cards, active filter chips, and sorting
- Client-side and server-side filters with debounce, caching, and request deduplication
- Global store for filter state (Zustand, Redux Toolkit, Riverpod, Bloc)
- Filter serialization into deep link for link sharing and session restoration
- Performance optimization: FlashList or SliverList, FastImage, virtualization
- Pagination or infinite scroll with next page preloading
Timeline and Cost
A basic catalog with client-side filters takes 3–5 working days. The full version with server integration, filter persistence, offline cache, and two view modes takes 8 to 12 working days. Cost starts from $800 for an MVP and from $2,000 for a full-featured solution. We provide a free estimate after analyzing your requirements. Contact us for a consultation and receive an accurate timeline and budget.
Our experience in over 80 mobile catalog development projects allows us to guarantee results: list performance, filtering convenience, and stable operation when scaling assortment. We work with clients from Russia, Belarus, and Israel, and select the stack to fit your existing infrastructure. Each project is accompanied by documentation, access transfer, and post-launch support.
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
| Parameter |
iOS (HIG) |
Android (Material Design 3) |
| Minimum tap target |
44×44 pt |
48×48 dp |
| Safe area |
safeAreaLayoutGuide / safeAreaPadding |
Insets in WindowInsets |
| Back gesture |
Swipe from left edge |
System back gesture (Android 10+) |
| Color scheme |
System dark/light |
Dynamic Color from wallpaper |
| Typography |
San Francisco (Dynamic Type) |
Roboto (Material Type Scale) |
| Haptic feedback |
UIImpactFeedbackGenerator |
HapticFeedbackConstants (Compose) |
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:
| Deliverable |
Description |
| User flows and wireframes |
Screen structure and user paths |
| Design system |
Design tokens, components, Style Dictionary for export |
| UI layouts (Figma) |
All screens following platform guidelines |
| Interactive prototype |
Prototype with variables and animations |
| Development specification |
Zeplin / Figma Dev Mode with dimensions, margins, states |
| Maintenance guide |
Recommendations for adding new screens and components |
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:
| Scope |
Timeline |
| Redesign of 3–5 screens |
1–2 weeks |
| MVP (10–15 screens) |
3–5 weeks |
| Full product (30+ screens) |
6–10 weeks |
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.
