"Browser-like features" — tabs, navigation history, bookmarks, find-in-page, a tab manager, a mini DOM renderer — test whether you can model a stateful system, pick data structures, and reason about lifecycle, memory, and edge cases. Approach it like any system design: clarify scope, model state, then go deep.

1. Clarify scope

Browsers are huge — pin down which feature and which behaviors. "Tabs" could mean just switching, or also drag-reorder, persistence, lazy-loading, and crash recovery. Agree on the subset.

2. Model the state + data structures

Each feature has a natural structure:

• Navigation history (back/forward) — two stacks (back, forward). Navigate → push current to back, clear forward. Back → pop back, push to forward. Same shape as undo/redo.
• Tabs — an ordered list of tab objects { id, url, title, state, lastActive } + an activeTabId. Reorder = array move.
• DOM / mini-renderer — a tree; rendering = recursive traversal.
• Find-in-page — text index + a list of match ranges + a current-match pointer.
• Bookmarks — a tree (folders) or flat list with tags.

Naming the right structure quickly is the core signal.

3. Lifecycle & persistence

• Persistence — tabs/history/bookmarks survive restarts → localStorage/IndexedDB; restore on load.
• Lifecycle — tabs mount/unmount; suspend inactive tabs (don't keep 100 live) and restore on activation.
• Crash recovery — periodically snapshot session state.

4. Memory management — the part that separates levels

A browser can't keep everything live:

• Lazy-load — don't render a tab's content until activated.
• Suspend / evict — serialize inactive tabs' state, free their DOM/memory, rehydrate on return (this is exactly what real browsers do).
• Cap in-memory instances; LRU-evict the rest to storage.

5. Performance

• Virtualize if there can be thousands of items (a huge history list, a tab overflow menu).
• Debounce expensive work (find-in-page search on input).
• Keep switching instant — pre-warm the likely-next tab.

6. Edge cases (always raise these)

• History: navigating mid-stack truncates forward; duplicate entries; max depth.
• Tabs: closing the active tab (which becomes active next?), closing the last tab, restoring a closed tab.
• Find: zero matches, wrapping past the last match, matches inside collapsed/hidden content, live DOM changes.
• Persistence: corrupted/stale stored state; storage quota exceeded.

The framework

Scope it down → model state with the right data structure → handle lifecycle & persistence → manage memory (lazy/suspend/evict) → performance → edge cases. Browser-like features are really "stateful systems with constrained resources" — show you can reason about all of it, not just the happy path.