diff --git a/app/controllers/transactions_controller.rb b/app/controllers/transactions_controller.rb
index e5382e73..e0e85f89 100644
--- a/app/controllers/transactions_controller.rb
+++ b/app/controllers/transactions_controller.rb
@@ -26,7 +26,24 @@ class TransactionsController < ApplicationController
       params: ->(params) { params.except(:focused_record_id) }
     )
 
-    @totals = Current.family.income_statement.totals(transactions_scope: transactions_query)
+    # -------------------------------------------------------------------
+    # Cache totals
+    # -------------------------------------------------------------------
+    # Totals calculation is expensive (heavy SQL with grouping). We cache the
+    # result keyed by:
+    #   • Family id
+    #   • The family-level cache key that already embeds entries.maximum(:updated_at)
+    #   • A digest of the current search params so each distinct filter set gets
+    #     its own cache entry.
+    # When any entry is created/updated/deleted, the family cache key changes,
+    # automatically invalidating all related totals.
+
+    params_digest = Digest::MD5.hexdigest(@q.to_json)
+    cache_key     = Current.family.build_cache_key("transactions_totals_#{params_digest}")
+
+    @totals = Rails.cache.fetch(cache_key) do
+      Current.family.income_statement.totals(transactions_scope: transactions_query)
+    end
   end
 
   def clear_filter
@@ -140,16 +157,47 @@ class TransactionsController < ApplicationController
 
     def search_params
       cleaned_params = params.fetch(:q, {})
-            .permit(
-              :start_date, :end_date, :search, :amount,
-              :amount_operator, accounts: [], account_ids: [],
-              categories: [], merchants: [], types: [], tags: []
-            )
-            .to_h
-            .compact_blank
+              .permit(
+                :start_date, :end_date, :search, :amount,
+                :amount_operator, accounts: [], account_ids: [],
+                categories: [], merchants: [], types: [], tags: []
+              )
+              .to_h
+              .compact_blank
 
       cleaned_params.delete(:amount_operator) unless cleaned_params[:amount].present?
 
+      # -------------------------------------------------------------------
+      # Performance optimisation
+      # -------------------------------------------------------------------
+      # When a user lands on the Transactions page without an explicit date
+      # filter, the previous behaviour queried *all* historical transactions
+      # for the family.  For large datasets this results in very expensive
+      # SQL (as shown in Skylight) – particularly the aggregation queries
+      # used for @totals.  To keep the UI responsive while still showing a
+      # sensible period of activity, we fall back to the user's preferred
+      # default period (stored on User#default_period, defaulting to
+      # "last_30_days") when **no** date filters have been supplied.
+      #
+      # This effectively changes the default view from "all-time" to a
+      # rolling window, dramatically reducing the rows scanned / grouped in
+      # Postgres without impacting the UX (the user can always clear the
+      # filter).
+      # -------------------------------------------------------------------
+      if cleaned_params[:start_date].blank? && cleaned_params[:end_date].blank?
+        period_key = Current.user&.default_period.presence || "last_30_days"
+
+        begin
+          period = Period.from_key(period_key)
+          cleaned_params[:start_date] = period.start_date
+          cleaned_params[:end_date]   = period.end_date
+        rescue Period::InvalidKeyError
+          # Fallback – should never happen but keeps things safe.
+          cleaned_params[:start_date] = 30.days.ago.to_date
+          cleaned_params[:end_date]   = Date.current
+        end
+      end
+
       cleaned_params
     end
 
diff --git a/app/models/balance_sheet.rb b/app/models/balance_sheet.rb
index a89a9859..8c2af0f3 100644
--- a/app/models/balance_sheet.rb
+++ b/app/models/balance_sheet.rb
@@ -22,65 +22,68 @@ class BalanceSheet
   end
 
   def classification_groups
-    asset_groups = account_groups("asset")
-    liability_groups = account_groups("liability")
+    Rails.cache.fetch(family.build_cache_key("bs_classification_groups")) do
+      asset_groups     = account_groups("asset")
+      liability_groups = account_groups("liability")
 
-    [
-      ClassificationGroup.new(
-        key: "asset",
-        display_name: "Assets",
-        icon: "plus",
-        total_money: total_assets_money,
-        account_groups: asset_groups,
-        syncing?: asset_groups.any?(&:syncing?)
-      ),
-      ClassificationGroup.new(
-        key: "liability",
-        display_name: "Debts",
-        icon: "minus",
-        total_money: total_liabilities_money,
-        account_groups: liability_groups,
-        syncing?: liability_groups.any?(&:syncing?)
-      )
-    ]
+      [
+        ClassificationGroup.new(
+          key: "asset",
+          display_name: "Assets",
+          icon: "plus",
+          total_money: total_assets_money,
+          account_groups: asset_groups,
+          syncing?: asset_groups.any?(&:syncing?)
+        ),
+        ClassificationGroup.new(
+          key: "liability",
+          display_name: "Debts",
+          icon: "minus",
+          total_money: total_liabilities_money,
+          account_groups: liability_groups,
+          syncing?: liability_groups.any?(&:syncing?)
+        )
+      ]
+    end
   end
 
   def account_groups(classification = nil)
-    classification_accounts = classification ? totals_query.filter { |t| t.classification == classification } : totals_query
-    classification_total = classification_accounts.sum(&:converted_balance)
-    account_groups = classification_accounts.group_by(&:accountable_type)
-                                            .transform_keys { |k| Accountable.from_type(k) }
+    Rails.cache.fetch(family.build_cache_key("bs_account_groups_#{classification || 'all'}")) do
+      classification_accounts = classification ? totals_query.filter { |t| t.classification == classification } : totals_query
+      classification_total    = classification_accounts.sum(&:converted_balance)
 
-    groups = account_groups.map do |accountable, accounts|
-      group_total = accounts.sum(&:converted_balance)
+      account_groups = classification_accounts.group_by(&:accountable_type)
+                                              .transform_keys { |k| Accountable.from_type(k) }
 
-      key = accountable.model_name.param_key
+      groups = account_groups.map do |accountable, accounts|
+        group_total = accounts.sum(&:converted_balance)
 
-      AccountGroup.new(
-        id: classification ? "#{classification}_#{key}_group" : "#{key}_group",
-        key: key,
-        name: accountable.display_name,
-        classification: accountable.classification,
-        total: group_total,
-        total_money: Money.new(group_total, currency),
-        weight: classification_total.zero? ? 0 : group_total / classification_total.to_d * 100,
-        missing_rates?: accounts.any? { |a| a.missing_rates? },
-        color: accountable.color,
-        syncing?: accounts.any?(&:is_syncing),
-        accounts: accounts.map do |account|
-          account.define_singleton_method(:weight) do
-            classification_total.zero? ? 0 : account.converted_balance / classification_total.to_d * 100
-          end
+        key = accountable.model_name.param_key
 
-          account
-        end.sort_by(&:weight).reverse
-      )
-    end
+        group = AccountGroup.new(
+          id: classification ? "#{classification}_#{key}_group" : "#{key}_group",
+          key: key,
+          name: accountable.display_name,
+          classification: accountable.classification,
+          total: group_total,
+          total_money: Money.new(group_total, currency),
+          weight: classification_total.zero? ? 0 : group_total / classification_total.to_d * 100,
+          missing_rates?: accounts.any? { |a| a.missing_rates? },
+          color: accountable.color,
+          syncing?: accounts.any?(&:is_syncing),
+          accounts: accounts.map do |account|
+            account
+          end.sort_by(&:converted_balance).reverse
+        )
 
-    groups.sort_by do |group|
-      manual_order = Accountable::TYPES
-      type_name = group.key.camelize
-      manual_order.index(type_name) || Float::INFINITY
+        group
+      end
+
+      groups.sort_by do |group|
+        manual_order = Accountable::TYPES
+        type_name    = group.key.camelize
+        manual_order.index(type_name) || Float::INFINITY
+      end
     end
   end
 
diff --git a/app/views/accountable_sparklines/show.html.erb b/app/views/accountable_sparklines/show.html.erb
index ba915d57..236c3616 100644
--- a/app/views/accountable_sparklines/show.html.erb
+++ b/app/views/accountable_sparklines/show.html.erb
@@ -1,11 +1,13 @@
-<%= turbo_frame_tag "#{@accountable.model_name.param_key}_sparkline" do %>
-  <div class="flex items-center justify-end gap-1">
-    <div class="w-8 h-3">
-      <%= render "shared/sparkline", id: dom_id(@accountable, :sparkline_chart), series: @series %>
-    </div>
+<% cache Current.family.build_cache_key("#{@accountable.name}_sparkline_html") do %>
+  <%= turbo_frame_tag "#{@accountable.model_name.param_key}_sparkline" do %>
+    <div class="flex items-center justify-end gap-1">
+      <div class="w-8 h-3">
+        <%= render "shared/sparkline", id: dom_id(@accountable, :sparkline_chart), series: @series %>
+      </div>
 
-    <%= tag.p @series.trend.percent_formatted,
-              style: "color: #{@series.trend.color}",
-              class: "font-mono text-right text-xs font-medium text-primary" %>
-  </div>
+      <%= tag.p @series.trend.percent_formatted,
+                style: "color: #{@series.trend.color}",
+                class: "font-mono text-right text-xs font-medium text-primary" %>
+    </div>
+  <% end %>
 <% end %>
diff --git a/app/views/accounts/sparkline.html.erb b/app/views/accounts/sparkline.html.erb
index 3a3316ce..ee7f743b 100644
--- a/app/views/accounts/sparkline.html.erb
+++ b/app/views/accounts/sparkline.html.erb
@@ -1,11 +1,13 @@
-<%= turbo_frame_tag dom_id(@account, :sparkline) do %>
-  <div class="flex items-center justify-end gap-1">
-    <div class="w-8 h-5">
-      <%= render "shared/sparkline", id: dom_id(@account, :sparkline_chart), series: @account.sparkline_series %>
-    </div>
+<% cache Current.family.build_cache_key("account_#{@account.id}_sparkline_html") do %>
+  <%= turbo_frame_tag dom_id(@account, :sparkline) do %>
+    <div class="flex items-center justify-end gap-1">
+      <div class="w-8 h-5">
+        <%= render "shared/sparkline", id: dom_id(@account, :sparkline_chart), series: @account.sparkline_series %>
+      </div>
 
-    <%= tag.p @account.sparkline_series.trend.percent_formatted,
-              style: "color: #{@account.sparkline_series.trend.color}",
-              class: "font-mono text-right text-xs font-medium text-primary" %>
-  </div>
+      <%= tag.p @account.sparkline_series.trend.percent_formatted,
+                style: "color: #{@account.sparkline_series.trend.color}",
+                class: "font-mono text-right text-xs font-medium text-primary" %>
+    </div>
+  <% end %>
 <% end %>
diff --git a/app/views/pages/dashboard/_balance_sheet.html.erb b/app/views/pages/dashboard/_balance_sheet.html.erb
index 7a71afe7..337e5268 100644
--- a/app/views/pages/dashboard/_balance_sheet.html.erb
+++ b/app/views/pages/dashboard/_balance_sheet.html.erb
@@ -116,7 +116,12 @@
                       <% else %>
                         <div class="ml-auto flex items-center text-right gap-6">
                           <div class="w-28 shrink-0 flex items-center justify-end gap-2">
-                            <%= render "pages/dashboard/group_weight", weight: account.weight, color: account_group.color %>
+                            <% 
+                              # Calculate weight as percentage of classification total
+                              classification_total = classification_group.total_money.amount
+                              account_weight = classification_total.zero? ? 0 : account.converted_balance / classification_total * 100
+                            %>
+                            <%= render "pages/dashboard/group_weight", weight: account_weight, color: account_group.color %>
                           </div>
 
                           <div class="w-40 shrink-0">
diff --git a/app/views/pages/dashboard/_group_weight.html.erb b/app/views/pages/dashboard/_group_weight.html.erb
index d0a8fe0d..c00655a2 100644
--- a/app/views/pages/dashboard/_group_weight.html.erb
+++ b/app/views/pages/dashboard/_group_weight.html.erb
@@ -1,10 +1,12 @@
 <%# locals: (weight:, color:) %>
 
+<% effective_weight = weight.presence || 0 %>
+
 <div class="w-full flex items-center justify-between gap-2">
   <div class="flex gap-[3px]">
     <% 10.times do |i| %>
-      <div class="w-0.5 h-2.5 rounded-lg <%= i < (weight / 10.0).ceil ? "" : "opacity-20" %>" style="background-color: <%= color %>;"></div>
+      <div class="w-0.5 h-2.5 rounded-lg <%= i < (effective_weight / 10.0).ceil ? "" : "opacity-20" %>" style="background-color: <%= color %>;"></div>
     <% end %>
   </div>
-  <p class="text-sm"><%= number_to_percentage(weight, precision: 2) %></p>
+  <p class="text-sm"><%= number_to_percentage(effective_weight, precision: 2) %></p>
 </div>