diff --git a/bin/clean.sh b/bin/clean.sh
index 55f5789..53bdba5 100755
--- a/bin/clean.sh
+++ b/bin/clean.sh
@@ -121,6 +121,13 @@ SECTION_ACTIVITY=0
 files_cleaned=0
 total_size_cleaned=0
 whitelist_skipped_count=0
+PROJECT_ARTIFACT_HINT_DETECTED=false
+PROJECT_ARTIFACT_HINT_COUNT=0
+PROJECT_ARTIFACT_HINT_TRUNCATED=false
+PROJECT_ARTIFACT_HINT_EXAMPLES=()
+PROJECT_ARTIFACT_HINT_ESTIMATED_KB=0
+PROJECT_ARTIFACT_HINT_ESTIMATE_SAMPLES=0
+PROJECT_ARTIFACT_HINT_ESTIMATE_PARTIAL=false
 
 # shellcheck disable=SC2329
 note_activity() {
@@ -294,6 +301,427 @@ classify_cleanup_risk() {
     echo "MEDIUM|User data files"
 }
 
+# Quick reminder probe for project build artifacts handled by `mo purge`.
+# Designed to be very fast: shallow directory checks only, no du/find scans.
+# shellcheck disable=SC2329
+load_quick_purge_hint_paths() {
+    local config_file="$HOME/.config/mole/purge_paths"
+    local -a paths=()
+
+    if [[ -f "$config_file" ]]; then
+        while IFS= read -r line; do
+            line="${line#"${line%%[![:space:]]*}"}"
+            line="${line%"${line##*[![:space:]]}"}"
+
+            [[ -z "$line" || "$line" =~ ^# ]] && continue
+            [[ "$line" == ~* ]] && line="${line/#~/$HOME}"
+            paths+=("$line")
+        done < "$config_file"
+    fi
+
+    if [[ ${#paths[@]} -eq 0 ]]; then
+        paths=(
+            "$HOME/www"
+            "$HOME/dev"
+            "$HOME/Projects"
+            "$HOME/GitHub"
+            "$HOME/Code"
+            "$HOME/Workspace"
+            "$HOME/Repos"
+            "$HOME/Development"
+        )
+    fi
+
+    if [[ ${#paths[@]} -gt 0 ]]; then
+        printf '%s\n' "${paths[@]}"
+    fi
+}
+
+# shellcheck disable=SC2329
+record_project_artifact_hint() {
+    local path="$1"
+
+    ((PROJECT_ARTIFACT_HINT_COUNT++))
+
+    if [[ ${#PROJECT_ARTIFACT_HINT_EXAMPLES[@]} -lt 2 ]]; then
+        PROJECT_ARTIFACT_HINT_EXAMPLES+=("${path/#$HOME/~}")
+    fi
+
+    local sample_max=3
+
+    if [[ $PROJECT_ARTIFACT_HINT_ESTIMATE_SAMPLES -ge $sample_max ]]; then
+        PROJECT_ARTIFACT_HINT_ESTIMATE_PARTIAL=true
+        return 0
+    fi
+
+    local timeout_seconds="0.8"
+
+    local du_tmp
+    du_tmp=$(mktemp)
+
+    local du_status=0
+    if run_with_timeout "$timeout_seconds" du -skP "$path" > "$du_tmp" 2> /dev/null; then
+        du_status=0
+    else
+        du_status=$?
+    fi
+
+    if [[ $du_status -eq 0 ]]; then
+        local size_kb
+        size_kb=$(awk 'NR==1 {print $1; exit}' "$du_tmp")
+        if [[ "$size_kb" =~ ^[0-9]+$ ]]; then
+            ((PROJECT_ARTIFACT_HINT_ESTIMATED_KB += size_kb))
+            ((PROJECT_ARTIFACT_HINT_ESTIMATE_SAMPLES++))
+        else
+            PROJECT_ARTIFACT_HINT_ESTIMATE_PARTIAL=true
+        fi
+    else
+        PROJECT_ARTIFACT_HINT_ESTIMATE_PARTIAL=true
+    fi
+
+    rm -f "$du_tmp"
+}
+
+# shellcheck disable=SC2329
+is_quick_purge_project_root() {
+    local dir="$1"
+    local indicator
+
+    # Mirror purge single-project detection so configured project roots like
+    # ~/www/Pake can still surface direct-child artifacts such as target/.
+    local -a indicators=(
+        "lerna.json"
+        "pnpm-workspace.yaml"
+        "nx.json"
+        "rush.json"
+        "package.json"
+        "Cargo.toml"
+        "go.mod"
+        "pyproject.toml"
+        "requirements.txt"
+        "pom.xml"
+        "build.gradle"
+        "Gemfile"
+        "composer.json"
+        "pubspec.yaml"
+        "Makefile"
+        "build.zig"
+        "build.zig.zon"
+        ".git"
+    )
+
+    for indicator in "${indicators[@]}"; do
+        if [[ -e "$dir/$indicator" ]]; then
+            return 0
+        fi
+    done
+
+    return 1
+}
+
+# shellcheck disable=SC2329
+probe_project_artifact_hints() {
+    PROJECT_ARTIFACT_HINT_DETECTED=false
+    PROJECT_ARTIFACT_HINT_COUNT=0
+    PROJECT_ARTIFACT_HINT_TRUNCATED=false
+    PROJECT_ARTIFACT_HINT_EXAMPLES=()
+    PROJECT_ARTIFACT_HINT_ESTIMATED_KB=0
+    PROJECT_ARTIFACT_HINT_ESTIMATE_SAMPLES=0
+    PROJECT_ARTIFACT_HINT_ESTIMATE_PARTIAL=false
+
+    local max_projects=200
+    local max_projects_per_root=0
+    local max_nested_per_project=120
+    local max_matches=12
+
+    # Fast hint list tracks most purge targets, but excludes high-noise names
+    # like `bin` and `vendor` that need deeper context checks in purge logic.
+    local -a target_names=(
+        "node_modules"
+        "target"
+        "build"
+        "dist"
+        "venv"
+        ".venv"
+        ".pytest_cache"
+        ".mypy_cache"
+        ".tox"
+        ".nox"
+        ".ruff_cache"
+        ".gradle"
+        "__pycache__"
+        ".next"
+        ".nuxt"
+        ".output"
+        "obj"
+        ".turbo"
+        ".parcel-cache"
+        ".dart_tool"
+        ".zig-cache"
+        "zig-out"
+        ".angular"
+        ".svelte-kit"
+        ".astro"
+        "coverage"
+        "DerivedData"
+        "Pods"
+        ".cxx"
+        ".expo"
+    )
+
+    local -a scan_roots=()
+    while IFS= read -r path; do
+        [[ -n "$path" ]] && scan_roots+=("$path")
+    done < <(load_quick_purge_hint_paths)
+
+    [[ ${#scan_roots[@]} -eq 0 ]] && return 0
+
+    # Fairness: avoid one very large root exhausting the entire scan budget.
+    if [[ $max_projects_per_root -le 0 ]]; then
+        max_projects_per_root=$(((max_projects + ${#scan_roots[@]} - 1) / ${#scan_roots[@]}))
+        [[ $max_projects_per_root -lt 25 ]] && max_projects_per_root=25
+    fi
+    [[ $max_projects_per_root -gt $max_projects ]] && max_projects_per_root=$max_projects
+
+    local nullglob_was_set=0
+    if shopt -q nullglob; then
+        nullglob_was_set=1
+    fi
+    shopt -s nullglob
+
+    local scanned_projects=0
+    local stop_scan=false
+    local root project_dir nested_dir target_name candidate
+
+    for root in "${scan_roots[@]}"; do
+        [[ -d "$root" ]] || continue
+        local root_projects_scanned=0
+
+        if is_quick_purge_project_root "$root"; then
+            ((scanned_projects++))
+            ((root_projects_scanned++))
+            if [[ $scanned_projects -gt $max_projects ]]; then
+                PROJECT_ARTIFACT_HINT_TRUNCATED=true
+                stop_scan=true
+                break
+            fi
+
+            for target_name in "${target_names[@]}"; do
+                candidate="$root/$target_name"
+                if [[ -d "$candidate" ]]; then
+                    record_project_artifact_hint "$candidate"
+                fi
+            done
+        fi
+        [[ "$stop_scan" == "true" ]] && break
+
+        if [[ $root_projects_scanned -ge $max_projects_per_root ]]; then
+            PROJECT_ARTIFACT_HINT_TRUNCATED=true
+            continue
+        fi
+
+        for project_dir in "$root"/*/; do
+            [[ -d "$project_dir" ]] || continue
+            project_dir="${project_dir%/}"
+
+            local project_name
+            project_name=$(basename "$project_dir")
+            [[ "$project_name" == .* ]] && continue
+
+            if [[ $root_projects_scanned -ge $max_projects_per_root ]]; then
+                PROJECT_ARTIFACT_HINT_TRUNCATED=true
+                break
+            fi
+
+            ((scanned_projects++))
+            ((root_projects_scanned++))
+            if [[ $scanned_projects -gt $max_projects ]]; then
+                PROJECT_ARTIFACT_HINT_TRUNCATED=true
+                stop_scan=true
+                break
+            fi
+
+            for target_name in "${target_names[@]}"; do
+                candidate="$project_dir/$target_name"
+                if [[ -d "$candidate" ]]; then
+                    record_project_artifact_hint "$candidate"
+                fi
+            done
+            [[ "$stop_scan" == "true" ]] && break
+
+            local nested_count=0
+            for nested_dir in "$project_dir"/*/; do
+                [[ -d "$nested_dir" ]] || continue
+                nested_dir="${nested_dir%/}"
+
+                local nested_name
+                nested_name=$(basename "$nested_dir")
+                [[ "$nested_name" == .* ]] && continue
+
+                case "$nested_name" in
+                    node_modules | target | build | dist | DerivedData | Pods)
+                        continue
+                        ;;
+                esac
+
+                ((nested_count++))
+                if [[ $nested_count -gt $max_nested_per_project ]]; then
+                    break
+                fi
+
+                for target_name in "${target_names[@]}"; do
+                    candidate="$nested_dir/$target_name"
+                    if [[ -d "$candidate" ]]; then
+                        record_project_artifact_hint "$candidate"
+                    fi
+                done
+
+                [[ "$stop_scan" == "true" ]] && break
+            done
+
+            [[ "$stop_scan" == "true" ]] && break
+        done
+
+        [[ "$stop_scan" == "true" ]] && break
+    done
+
+    if [[ $nullglob_was_set -eq 0 ]]; then
+        shopt -u nullglob
+    fi
+
+    if [[ $PROJECT_ARTIFACT_HINT_COUNT -gt 0 ]]; then
+        PROJECT_ARTIFACT_HINT_DETECTED=true
+    fi
+
+    # Preserve a compact display hint if candidate count is large, but do not
+    # stop scanning early solely because we exceeded this threshold.
+    if [[ $PROJECT_ARTIFACT_HINT_COUNT -gt $max_matches ]]; then
+        PROJECT_ARTIFACT_HINT_TRUNCATED=true
+    fi
+
+    return 0
+}
+
+# shellcheck disable=SC2329
+show_system_data_hint_notice() {
+    local min_gb=2
+    local timeout_seconds="0.8"
+    local max_hits=3
+
+    local threshold_kb=$((min_gb * 1024 * 1024))
+    local -a clue_labels=()
+    local -a clue_sizes=()
+    local -a clue_paths=()
+
+    local -a labels=(
+        "Xcode DerivedData"
+        "Xcode Archives"
+        "iPhone backups"
+        "Simulator data"
+        "Docker Desktop data"
+        "Mail data"
+    )
+    local -a paths=(
+        "$HOME/Library/Developer/Xcode/DerivedData"
+        "$HOME/Library/Developer/Xcode/Archives"
+        "$HOME/Library/Application Support/MobileSync/Backup"
+        "$HOME/Library/Developer/CoreSimulator/Devices"
+        "$HOME/Library/Containers/com.docker.docker/Data"
+        "$HOME/Library/Mail"
+    )
+
+    local i
+    for i in "${!paths[@]}"; do
+        local path="${paths[$i]}"
+        [[ -d "$path" ]] || continue
+
+        local du_tmp
+        du_tmp=$(mktemp)
+        local du_status=0
+        if run_with_timeout "$timeout_seconds" du -skP "$path" > "$du_tmp" 2> /dev/null; then
+            du_status=0
+        else
+            du_status=$?
+        fi
+
+        if [[ $du_status -eq 0 ]]; then
+            local size_kb
+            size_kb=$(awk 'NR==1 {print $1; exit}' "$du_tmp")
+            if [[ "$size_kb" =~ ^[0-9]+$ ]] && [[ "$size_kb" -ge "$threshold_kb" ]]; then
+                clue_labels+=("${labels[$i]}")
+                clue_sizes+=("$size_kb")
+                clue_paths+=("${path/#$HOME/~}")
+                if [[ ${#clue_labels[@]} -ge $max_hits ]]; then
+                    rm -f "$du_tmp"
+                    break
+                fi
+            fi
+        fi
+        rm -f "$du_tmp"
+    done
+
+    if [[ ${#clue_labels[@]} -eq 0 ]]; then
+        note_activity
+        echo -e "  ${GREEN}${ICON_SUCCESS}${NC} No common System Data clues detected"
+        return 0
+    fi
+
+    note_activity
+
+    for i in "${!clue_labels[@]}"; do
+        local human_size
+        human_size=$(bytes_to_human "$((clue_sizes[$i] * 1024))")
+        echo -e "  ${GREEN}${ICON_LIST}${NC} ${clue_labels[$i]}: ${human_size}"
+        echo -e "  ${GRAY}${ICON_SUBLIST}${NC} Path: ${GRAY}${clue_paths[$i]}${NC}"
+    done
+    echo -e "  ${GRAY}${ICON_REVIEW}${NC} Review: mo analyze, Device backups, docker system df"
+}
+
+# shellcheck disable=SC2329
+show_project_artifact_hint_notice() {
+    probe_project_artifact_hints
+
+    if [[ "$PROJECT_ARTIFACT_HINT_DETECTED" != "true" ]]; then
+        return 0
+    fi
+
+    note_activity
+
+    local hint_count_label="$PROJECT_ARTIFACT_HINT_COUNT"
+    [[ "$PROJECT_ARTIFACT_HINT_TRUNCATED" == "true" ]] && hint_count_label="${hint_count_label}+"
+
+    local example_text=""
+    if [[ ${#PROJECT_ARTIFACT_HINT_EXAMPLES[@]} -gt 0 ]]; then
+        example_text="${PROJECT_ARTIFACT_HINT_EXAMPLES[0]}"
+        if [[ ${#PROJECT_ARTIFACT_HINT_EXAMPLES[@]} -gt 1 ]]; then
+            example_text+=", ${PROJECT_ARTIFACT_HINT_EXAMPLES[1]}"
+        fi
+    fi
+
+    if [[ $PROJECT_ARTIFACT_HINT_ESTIMATE_SAMPLES -gt 0 ]]; then
+        local estimate_human
+        estimate_human=$(bytes_to_human "$((PROJECT_ARTIFACT_HINT_ESTIMATED_KB * 1024))")
+
+        local estimate_is_partial="$PROJECT_ARTIFACT_HINT_ESTIMATE_PARTIAL"
+        if [[ "$PROJECT_ARTIFACT_HINT_TRUNCATED" == "true" ]] || [[ $PROJECT_ARTIFACT_HINT_ESTIMATE_SAMPLES -lt $PROJECT_ARTIFACT_HINT_COUNT ]]; then
+            estimate_is_partial=true
+        fi
+
+        if [[ "$estimate_is_partial" == "true" ]]; then
+            echo -e "  ${GREEN}${ICON_LIST}${NC} ${GREEN}${hint_count_label}${NC} candidates, at least ${estimate_human} sampled from ${PROJECT_ARTIFACT_HINT_ESTIMATE_SAMPLES} items"
+        else
+            echo -e "  ${GREEN}${ICON_LIST}${NC} ${GREEN}${hint_count_label}${NC} candidates, sampled ${estimate_human}"
+        fi
+    else
+        echo -e "  ${GREEN}${ICON_LIST}${NC} ${GREEN}${hint_count_label}${NC} candidates"
+    fi
+
+    if [[ -n "$example_text" ]]; then
+        echo -e "  ${GRAY}${ICON_SUBLIST}${NC} Examples: ${GRAY}${example_text}${NC}"
+    fi
+    echo -e "  ${GRAY}${ICON_REVIEW}${NC} Review: mo purge"
+}
+
 # shellcheck disable=SC2329
 safe_clean() {
     if [[ $# -eq 0 ]]; then
@@ -867,7 +1295,7 @@ perform_cleanup() {
             if [[ "$DRY_RUN" == "true" ]]; then
                 for pattern in "${WHITELIST_PATTERNS[@]}"; do
                     [[ "$pattern" == "$FINDER_METADATA_SENTINEL" ]] && continue
-                    echo -e "  ${GRAY}→ $pattern${NC}"
+                    echo -e "  ${GRAY}${ICON_SUBLIST}${NC} ${GRAY}${pattern}${NC}"
                 done
             fi
         fi
@@ -879,7 +1307,7 @@ perform_cleanup() {
         fda_status=$?
         if [[ $fda_status -eq 1 ]]; then
             echo ""
-            echo -e "${GRAY}${ICON_WARNING}${NC} ${GRAY}Tip: Grant Full Disk Access to your terminal in System Settings for best results${NC}"
+            echo -e "${GRAY}${ICON_REVIEW}${NC} ${GRAY}Grant Full Disk Access to your terminal in System Settings for best results${NC}"
         fi
     fi
 
@@ -976,6 +1404,16 @@ perform_cleanup() {
     check_large_file_candidates
     end_section
 
+    # ===== 15. System Data clues =====
+    start_section "System Data clues"
+    show_system_data_hint_notice
+    end_section
+
+    # ===== 16. Project artifacts =====
+    start_section "Project artifacts"
+    show_project_artifact_hint_notice
+    end_section
+
     # ===== Final summary =====
     echo ""
 
diff --git a/lib/clean/system.sh b/lib/clean/system.sh
index e73f5b8..5a14196 100644
--- a/lib/clean/system.sh
+++ b/lib/clean/system.sh
@@ -410,7 +410,8 @@ clean_local_snapshots() {
     local snapshot_count
     snapshot_count=$(echo "$snapshot_list" | { grep -Eo 'com\.apple\.TimeMachine\.[0-9]{4}-[0-9]{2}-[0-9]{2}-[0-9]{6}' || true; } | wc -l | awk '{print $1}')
     if [[ "$snapshot_count" =~ ^[0-9]+$ && "$snapshot_count" -gt 0 ]]; then
-        echo -e "  ${YELLOW}${ICON_WARNING}${NC} Time Machine local snapshots: ${GREEN}${snapshot_count}${NC}${GRAY}, Review: tmutil listlocalsnapshots /${NC}"
+        echo -e "  ${YELLOW}${ICON_WARNING}${NC} Time Machine local snapshots: ${GREEN}${snapshot_count}${NC}"
+        echo -e "  ${GRAY}${ICON_REVIEW}${NC} ${GRAY}Review: tmutil listlocalsnapshots /${NC}"
         note_activity
     fi
 }
diff --git a/lib/clean/user.sh b/lib/clean/user.sh
index 3871003..28a9cf0 100644
--- a/lib/clean/user.sh
+++ b/lib/clean/user.sh
@@ -887,7 +887,8 @@ check_large_file_candidates() {
         if [[ -n "$snapshot_list" ]]; then
             snapshot_count=$(echo "$snapshot_list" | { grep -Eo 'com\.apple\.TimeMachine\.[0-9]{4}-[0-9]{2}-[0-9]{2}-[0-9]{6}' || true; } | wc -l | awk '{print $1}')
             if [[ "$snapshot_count" =~ ^[0-9]+$ && "$snapshot_count" -gt 0 ]]; then
-                echo -e "  ${YELLOW}${ICON_WARNING}${NC} Time Machine local snapshots: ${GREEN}${snapshot_count}${NC}${GRAY}, Review: tmutil listlocalsnapshots /${NC}"
+                echo -e "  ${YELLOW}${ICON_WARNING}${NC} Time Machine local snapshots: ${GREEN}${snapshot_count}${NC}"
+                echo -e "  ${GRAY}${ICON_REVIEW}${NC} ${GRAY}Review: tmutil listlocalsnapshots /${NC}"
                 found_any=true
             fi
         fi
@@ -900,14 +901,14 @@ check_large_file_candidates() {
             echo -e "  ${YELLOW}${ICON_WARNING}${NC} Docker storage:"
             while IFS=$'\t' read -r dtype dsize dreclaim; do
                 [[ -z "$dtype" ]] && continue
-                echo -e "    ${GRAY}• $dtype: $dsize, Reclaimable: $dreclaim${NC}"
+                echo -e "    ${GRAY}${ICON_LIST} $dtype: $dsize, Reclaimable: $dreclaim${NC}"
             done <<< "$docker_output"
             found_any=true
         else
             docker_output=$(run_with_timeout 3 docker system df 2> /dev/null || true)
             if [[ -n "$docker_output" ]]; then
                 echo -e "  ${YELLOW}${ICON_WARNING}${NC} Docker storage:"
-                echo -e "    ${GRAY}• Run: docker system df${NC}"
+                echo -e "  ${GRAY}${ICON_REVIEW}${NC} ${GRAY}Run: docker system df${NC}"
                 found_any=true
             fi
         fi
diff --git a/lib/core/base.sh b/lib/core/base.sh
index d0f813b..452f2b0 100644
--- a/lib/core/base.sh
+++ b/lib/core/base.sh
@@ -35,8 +35,10 @@ readonly ICON_WARNING="◎"
 readonly ICON_EMPTY="○"
 readonly ICON_SOLID="●"
 readonly ICON_LIST="•"
+readonly ICON_SUBLIST="↳"
 readonly ICON_ARROW="➤"
 readonly ICON_DRY_RUN="→"
+readonly ICON_REVIEW="☞"
 readonly ICON_NAV_UP="↑"
 readonly ICON_NAV_DOWN="↓"