Scrolling and content management

1) Why think about scrolling

• speeds up the search for the right content (fewer clicks - more scrolling),
• gives a sense of control (anchors, "back to top," adhered filters),
• saves resources (lazy boot, virtualization),
• increases conversion (content seen earlier, CTA in the "thumb zone").

Principles: speed> density; context> noise; predictability> "magic."

2) Scrolling models: when to choose what

1. Classical pagination

Suitable for search results, tables, reporting. Pros: control, stable URLs, easy page navigation. Cons: more clicks, attention "gaps."

2. Infinite scroll

For feeds and catalogs with a low cost of error (news, content cards). Pros: Engagement, fewer clicks. Cons: "lost footer," hard to return, difficult addressing.

3. Hybrid: Show More/Load More

Compromise: widgets are loaded in batches per button. Pros: render control, footer availability, predictability. Cons: still linear.

4. Segmented scrolling (sections/anchors)

For long articles, references and wiki. Pros: document map, quick jumps. Cons: complicating navigation and table of contents.

• Catalogs/lobbies - hybrid or infinite + "go back to the beginning."
• Search/tables - pagination with page size and quick filters.
• Documentation/Longrid - segments with TOC and progress bar reading.

3) Information architecture and layout

Top header (sticky): search, quick filters, sorting; does not overlap content when it appears.
Sidebar (desktop): table of contents (TOC), filters; on mobile - leaving sheet.

Sticky elements: top filters, anchor menu, reading progress indicator, "Back to Top."

Content cards: predictable preview height → less layout jumps.

Empty states: Skeletons/shimmers, not "empty screens."

4) Scrolling behavior (micromechanics)

Inertia and physics: scrolling must appear "native"; do not break system patterns.
Axial lock: For horizons (carousels), lock the vertical axis after the motion threshold.
Snap points: Appropriate for carousels, cards and wizard steps. Do not abuse in long tapes.
Anchored scrolling: Maintain user focus and relative position when reloading.
Scroll-chaining: Limit the "flow" of events from nested containers so as not to "jump" to the page.

5) Attention management

Floating STA/" Deposit "/" Play ": in the thumb area, does not overlap content.
Progress bar reading: ruler on top, synchronized with anchors.
Table of Contents (TOC) - Current topic highlighted, shortcuts, top button.
Title anchors: stable hashes in URL; scrolling with cap height compensation.
Context "sticky" filters: fix after scrolling 1-2 screens.

6) Loading and rendering large tapes

Lazy loading: images, videos, blocks. The load threshold is ~ 1-2 screens ahead.
Virtualization/windowing: Draw only the visible area + buffer.

Placeholders/skeletons: predictable sizes, no "leaps."

Batch reloading: step 20-60 elements; balance between queries and renders.
Partition Cache: When going back, recover positions and loaded chunks.

7) Manage content in tape

Grouping: by dates/categories; separator headers stick.
Sorts and filters: visible and accessible, with indication of active conditions.
Collapse/Expand: For long descriptions, Show More.
Media in scrolling: auto-pause video out of sight; auto-play only without sound and with explicit control.
Error states: "Loss of network," "Failed to load" - with retry and saving position.

8) Availability and localization

All actions are available without gestures: "Download more," "To the beginning," "Open TOC."

Focus management: when navigating anchors - transfer focus to the section title.
Screen readers: descriptions for scroll buttons/TOC, order logic.
RTL: Mirror horizontal carousels and indicators.
Reduced motion: Disable "complex" animations and parallax for those who prefer simplified effects.

9) Performance: Goals and Metrics

INP (Interaction to Next Paint) key gestures/scrolling: ≤ 200 ms.
Scroll-jank: <1% frames> 16.7 ms on typical devices.
CLS (cumulative layout shift): ≤ 0.1 (especially during reloading).
TBT/Blocking: Avoid heavy synchronous computing while scrolling.
Memory: stable use during long sessions (no leaks during virtualization).

• passive scrolling listeners, deferred computation through 'requestAnimationFrame';
• "light" shadows/no complex blur while scrolling;
• Fixed or predictable card sizes
• saving redraws (batched updates).

10) Telemetry and events

• 'scroll _ start '/' scroll _ end '(source, speed, direction),
• 'content _ load _ request/success/fail '(stack, size),
• 'viewport _ item _ exposed '(id, visibility time),
• `toc_click`, `anchor_navigate`, `back_to_top_click`,
• 'list _ restore '(position, restore time).

• Depth Reached (how many ecraps/elements have been viewed),
• Exposure Time per Item (mean/median),
• Load Error Rate, Retry Rate,
• Scroll Abandonment (out before the next batch is loaded),
• Return-to-Position Success.

11) Patterns for different types of content

Catalogs of games/products: hybrid tape, sticky filters, virtualization, "Show more" button.

Longrides/wiki: TOC, progress bar, anchors, "copy link to section."

News feed: endless feed with separator dates, "go back to the last."

Tables/grids: pagination + "show by N," freezing headings and key columns, horizontal scrolling as needed.
Live feeds/log streams: auto-scroll with "pause/catch up," buffer limit.

12) Mobile features

Thumb zones: CTA and "to the beginning" - from below; filters - in the outgoing sheet.
"Pulling" footer: show only when stopped; do not interfere with scrolling.
Gestures: horizontal carousels - with axial lock; pull-to-refresh - only where expected.
Smoothness: 60 FPS check on "heavy" lists; reduce the density of effects.

13) Antipatterns

"Endless tape + hidden footer with no exit" (no links/contacts/rules).
Additional load that shifts the read - loss of context.
Floating panels overlapping text and CTA.
Unlimited height of cards → "wandering" layout-shifts.
Autoplay media with sound when visible.

No position recovery when "back."

14) Implementation checklist (by sprints)

Sprint 1: model selection (pagination/hybrid/infinite), basic scrolling containers, sticky hat/filters, "Back to Top."

Sprint 2: lazy loading of images/blocks, skeletons, predictable card sizes.
Sprint 3: list virtualization, save position and burst cache, anchors/TOC.
Sprint 4: Scroll and exposure telemetry, and scroll-jank alerts.
Sprint 5: accessibility (focus/readers), RTL, reduced motion, keyboard navigation (desktop).
Sprint 6: Fine Optimization: Axial Lock, Snap Points, UX Media Enhancement in Tape.

15) Glossary

Infinite Scroll - infinite loading of elements.
Windowing/Virtualization - Render only visible list items.
Anchored Scrolling - maintaining the relative position during reloading.
Scroll-jank - "jerking" due to skipping frames when scrolling.
TOC (Table of Contents) - table of contents with anchors.
CLS/INP - metrics of layout stability and responsiveness.

16) The bottom line

1. selects the appropriate flow model (pagination/hybrid/infinite),

2. gives control (anchors, TOC, sticky filters, "to the beginning"),

3. rendering fast and stable (lazy loading, virtualization, no shifts),

4. remains accessible and predictable,

5. measures telemetry and improves UX based on data.