diff --git a/app/assets/stylesheets/activity.css b/app/assets/stylesheets/activity.css
new file mode 100644
index 00000000..cd59ef0c
--- /dev/null
+++ b/app/assets/stylesheets/activity.css
@@ -0,0 +1,110 @@
+.recent-activity {
+    margin-top: 1rem;
+}
+
+.recent-activity h3 {
+    font-size: 1.2rem;
+    margin-bottom: 0.75rem;
+    color: var(--muted-color);
+}
+
+.activity-list {
+    max-height: 600px;
+    overflow-y: auto;
+}
+
+.activity-item {
+    padding: 0.75rem 0;
+    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
+    font-size: 0.9rem;
+}
+
+.activity-item:last-child {
+    border-bottom: none;
+}
+
+.activity-content {
+    margin: 0.5rem 0;
+}
+
+.activity-content p {
+    margin: 0;
+}
+
+.activity-time {
+    color: var(--muted-color);
+    font-size: 0.75rem;
+}
+
+.activity-actions {
+    display: flex;
+    margin-top: 0.5rem;
+}
+
+.give-kudos-btn {
+    display: inline-flex;
+    align-items: center;
+    background-color: rgba(var(--primary-color-rgb), 0.1);
+    color: var(--primary-color);
+    padding: 0.25rem 0.5rem;
+    border-radius: 4px;
+    text-decoration: none;
+    font-size: 0.75rem;
+    transition: background-color 0.2s;
+}
+
+.give-kudos-btn:hover {
+    background-color: rgba(var(--primary-color-rgb), 0.2);
+}
+
+.kudos-icon {
+    margin-right: 0.25rem;
+    font-style: normal;
+}
+
+.kudos-count {
+    margin-left: 0.25rem;
+    background: rgba(var(--primary-color-rgb), 0.2);
+    border-radius: 10px;
+    padding: 0.1rem 0.4rem;
+    font-size: 0.7rem;
+}
+
+.kudos-given,
+.kudos-received {
+    display: inline-flex;
+    align-items: center;
+    color: var(--primary-color);
+    padding: 0.25rem 0.5rem;
+    border-radius: 4px;
+    font-size: 0.75rem;
+    background-color: rgba(var(--primary-color-rgb), 0.1);
+}
+
+/* Dark mode overrides */
+@media (prefers-color-scheme: dark) {
+    .activity-item {
+        border-bottom: 1px solid rgba(255, 255, 255, 0.05);
+    }
+
+    .activity-time {
+        color: rgba(255, 255, 255, 0.5);
+    }
+
+    .give-kudos-btn {
+        background-color: rgba(var(--primary-color-rgb), 0.2);
+    }
+
+    .give-kudos-btn:hover {
+        background-color: rgba(var(--primary-color-rgb), 0.3);
+    }
+
+    .kudos-count {
+        background: rgba(var(--primary-color-rgb), 0.3);
+    }
+
+    .kudos-given,
+    .kudos-received {
+        background-color: rgba(var(--primary-color-rgb), 0.2);
+    }
+}
\ No newline at end of file
diff --git a/app/controllers/project_milestones_controller.rb b/app/controllers/project_milestones_controller.rb
new file mode 100644
index 00000000..996aee23
--- /dev/null
+++ b/app/controllers/project_milestones_controller.rb
@@ -0,0 +1,31 @@
+class ProjectMilestonesController < ApplicationController
+  before_action :authenticate_user!
+
+  def give_kudos
+    milestone = ProjectMilestone.find(params[:id])
+
+    # Don't allow users to give kudos to themselves
+    if milestone.user_id == current_user.id
+      return render json: { error: "You cannot give kudos to yourself" }, status: :unprocessable_entity
+    end
+
+    # Check if user already gave kudos
+    if milestone.kudos_from?(current_user.id)
+      return render json: { error: "You already gave kudos for this milestone" }, status: :unprocessable_entity
+    end
+
+    kudos = ProjectMilestoneKudos.new(
+      project_milestone: milestone,
+      user_id: current_user.id
+    )
+
+    if kudos.save
+      render json: {
+        success: true,
+        kudos_count: milestone.reload.kudos_count
+      }
+    else
+      render json: { error: kudos.errors.full_messages.join(", ") }, status: :unprocessable_entity
+    end
+  end
+end
diff --git a/app/javascript/controllers/kudos_controller.js b/app/javascript/controllers/kudos_controller.js
new file mode 100644
index 00000000..bb879e71
--- /dev/null
+++ b/app/javascript/controllers/kudos_controller.js
@@ -0,0 +1,43 @@
+import { Controller } from "@hotwired/stimulus"
+
+export default class extends Controller {
+    static targets = ["button"]
+
+    connect() {
+        console.log("Kudos controller connected")
+    }
+
+    giveKudos(event) {
+        event.preventDefault()
+
+        const button = event.currentTarget
+        const url = button.getAttribute("href")
+
+        fetch(url, {
+            method: "POST",
+            headers: {
+                "X-CSRF-Token": document.querySelector("meta[name='csrf-token']").content,
+                "Accept": "application/json"
+            }
+        })
+            .then(response => response.json())
+            .then(data => {
+                if (data.success) {
+                    // Replace the button with the kudos count
+                    const container = button.closest(".activity-actions")
+
+                    const kudosEl = document.createElement("span")
+                    kudosEl.classList.add("kudos-given")
+                    kudosEl.innerHTML = `<i class="kudos-icon">👏</i> ${data.kudos_count}`
+
+                    container.innerHTML = ""
+                    container.appendChild(kudosEl)
+                } else {
+                    console.error("Error giving kudos:", data.error)
+                }
+            })
+            .catch(error => {
+                console.error("Error giving kudos:", error)
+            })
+    }
+}
\ No newline at end of file
diff --git a/app/jobs/project_milestone_check_job.rb b/app/jobs/project_milestone_check_job.rb
new file mode 100644
index 00000000..6457830c
--- /dev/null
+++ b/app/jobs/project_milestone_check_job.rb
@@ -0,0 +1,50 @@
+class ProjectMilestoneCheckJob < ApplicationJob
+  queue_as :default
+
+  def perform
+    # Get all users with heartbeats in the last hour
+    active_users = Heartbeat.where("created_at > ?", 1.hour.ago)
+                          .distinct.pluck(:user_id)
+
+    active_users.each do |user_id|
+      check_hourly_milestones(user_id)
+    end
+  end
+
+  private
+
+  def check_hourly_milestones(user_id)
+    user = User.find_by(id: user_id)
+    return unless user
+
+    # Get projects with significant time in the last period
+    project_durations = user.heartbeats.today.group(:project).duration_seconds
+
+    project_durations.each do |project, duration|
+      next if project.blank?
+
+      # Convert to hours
+      hours = (duration / 3600.0).floor
+      next if hours < 1
+
+      # Check if we already have a milestone for this hour count
+      existing = ProjectMilestone.where(
+        user_id: user_id,
+        project_name: project,
+        milestone_type: :hourly,
+        milestone_value: hours
+      ).where("created_at > ?", 1.day.ago).exists?
+
+      # If no milestone exists, create one
+      unless existing
+        ProjectMilestone.create!(
+          user_id: user_id,
+          project_name: project,
+          milestone_type: :hourly,
+          milestone_value: hours
+        )
+        Rails.logger.info "Created hourly milestone for user #{user_id} on project #{project}: #{hours} hours"
+      end
+    end
+  end
+end
diff --git a/app/models/project_milestone.rb b/app/models/project_milestone.rb
new file mode 100644
index 00000000..c33faec3
--- /dev/null
+++ b/app/models/project_milestone.rb
@@ -0,0 +1,38 @@
+class ProjectMilestone < ApplicationRecord
+  belongs_to :user, foreign_key: :user_id
+
+  has_many :project_milestone_kudos, class_name: "ProjectMilestoneKudos"
+
+  validates :project_name, presence: true
+  validates :milestone_type, presence: true
+  validates :milestone_value, presence: true
+
+  # We keep this because I don't want to change the database schema
+  enum :milestone_type, {
+    hourly: 0,
+    daily: 1,
+    weekly: 2
+  }
+
+  # Get milestones for display in the sidebar
+  def self.recent_for_display(limit = 20)
+    where(milestone_type: :hourly)
+      .order(created_at: :desc)
+      .includes(:user, :project_milestone_kudos)
+      .limit(limit)
+  end
+
+  # Check if the current user has given kudos to this milestone
+  def kudos_from?(user_id)
+    project_milestone_kudos.where(user_id: user_id).exists?
+  end
+
+  # Get the kudos count
+  def kudos_count
+    project_milestone_kudos.count
+  end
+
+  def formatted_message
+    "completed #{milestone_value} hour#{'s' if milestone_value > 1} on #{project_name}"
+  end
+end
diff --git a/app/models/project_milestone_kudos.rb b/app/models/project_milestone_kudos.rb
new file mode 100644
index 00000000..7f652fbd
--- /dev/null
+++ b/app/models/project_milestone_kudos.rb
@@ -0,0 +1,6 @@
+class ProjectMilestoneKudos < ApplicationRecord
+  belongs_to :project_milestone
+  belongs_to :user
+
+  validates :project_milestone_id, uniqueness: { scope: :user_id }
+end
diff --git a/app/views/shared/_nav.html.erb b/app/views/shared/_nav.html.erb
index ea99a10c..60e3b328 100644
--- a/app/views/shared/_nav.html.erb
+++ b/app/views/shared/_nav.html.erb
@@ -75,4 +75,44 @@
       <% end %>
     <% end %>
   </ul>
+
+  <% if current_user %>
+    <hr />
+    
+    <div class="recent-activity">
+      <h3>Recent activity</h3>
+      
+      <div class="activity-list">
+        <% ProjectMilestone.recent_for_display(10).each do |milestone| %>
+          <div class="activity-item">
+            <%= render "shared/user_mention", user: milestone.user %>
+            <div class="activity-content">
+              <p><%= milestone.formatted_message %></p>
+              <div class="activity-actions">
+                <% if current_user.id != milestone.user_id %>
+                  <% if milestone.kudos_from?(current_user.id) %>
+                    <span class="kudos-given">
+                      <i class="kudos-icon">👏</i> <%= milestone.kudos_count %>
+                    </span>
+                  <% else %>
+                    <%= link_to give_kudos_project_milestone_path(milestone), 
+                                data: { turbo_method: :post, controller: "kudos", action: "click->kudos#giveKudos" },
+                                class: "give-kudos-btn" do %>
+                      <i class="kudos-icon">👏</i> Give kudos
+                      <% if milestone.kudos_count > 0 %><span class="kudos-count"><%= milestone.kudos_count %></span><% end %>
+                    <% end %>
+                  <% end %>
+                <% elsif milestone.kudos_count > 0 %>
+                  <span class="kudos-received">
+                    <i class="kudos-icon">👏</i> <%= milestone.kudos_count %>
+                  </span>
+                <% end %>
+              </div>
+            </div>
+            <span class="activity-time"><%= time_ago_in_words(milestone.created_at) %> ago</span>
+          </div>
+        <% end %>
+      </div>
+    </div>
+  <% end %>
 </aside>
\ No newline at end of file
diff --git a/config/initializers/good_job.rb b/config/initializers/good_job.rb
index f36065a2..37a56fb3 100644
--- a/config/initializers/good_job.rb
+++ b/config/initializers/good_job.rb
@@ -37,6 +37,10 @@
     scan_github_repos: {
       cron: "0 10 * * *",
       class: "ScanGithubReposJob"
+    },
+    project_milestone_check: {
+      cron: "*/5 * * * *",
+      class: "ProjectMilestoneCheckJob"
     }
   }
 end
diff --git a/config/routes.rb b/config/routes.rb
index d1a788f7..4a68579f 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -91,4 +91,10 @@ def self.matches?(request)
   end
 
   resources :scrapyard_leaderboards, only: [ :index, :show ]
+
+  resources :project_milestones, only: [] do
+    member do
+      post :give_kudos
+    end
+  end
 end
diff --git a/db/migrate/20250320052532_create_project_milestones.rb b/db/migrate/20250320052532_create_project_milestones.rb
new file mode 100644
index 00000000..4850db9f
--- /dev/null
+++ b/db/migrate/20250320052532_create_project_milestones.rb
@@ -0,0 +1,17 @@
+class CreateProjectMilestones < ActiveRecord::Migration[8.0]
+  def change
+    create_table :project_milestones do |t|
+      t.bigint :user_id, null: false
+      t.string :project_name, null: false
+      t.integer :milestone_type, null: false, default: 0
+      t.integer :milestone_value, null: false
+      t.boolean :notified, default: false
+
+      t.timestamps
+    end
+
+    add_index :project_milestones, :user_id
+    add_index :project_milestones, [ :user_id, :project_name, :milestone_type ]
+    add_index :project_milestones, :created_at
+  end
+end
diff --git a/db/migrate/20250320052612_create_project_milestone_kudos.rb b/db/migrate/20250320052612_create_project_milestone_kudos.rb
new file mode 100644
index 00000000..08560f19
--- /dev/null
+++ b/db/migrate/20250320052612_create_project_milestone_kudos.rb
@@ -0,0 +1,12 @@
+class CreateProjectMilestoneKudos < ActiveRecord::Migration[8.0]
+  def change
+    create_table :project_milestone_kudos do |t|
+      t.references :project_milestone, null: false, foreign_key: true
+      t.bigint :user_id, null: false
+
+      t.timestamps
+    end
+
+    add_index :project_milestone_kudos, [ :project_milestone_id, :user_id ], unique: true
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index db64e5cc..1e839ab8 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.0].define(version: 2025_03_19_193636) do
+ActiveRecord::Schema[8.0].define(version: 2025_03_20_052612) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "pg_catalog.plpgsql"
 
@@ -175,6 +175,28 @@
     t.integer "period_type", default: 0, null: false
   end
 
+  create_table "project_milestone_kudos", force: :cascade do |t|
+    t.bigint "project_milestone_id", null: false
+    t.bigint "user_id", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["project_milestone_id", "user_id"], name: "idx_on_project_milestone_id_user_id_218c1b857a", unique: true
+    t.index ["project_milestone_id"], name: "index_project_milestone_kudos_on_project_milestone_id"
+  end
+
+  create_table "project_milestones", force: :cascade do |t|
+    t.bigint "user_id", null: false
+    t.string "project_name", null: false
+    t.integer "milestone_type", default: 0, null: false
+    t.integer "milestone_value", null: false
+    t.boolean "notified", default: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["created_at"], name: "index_project_milestones_on_created_at"
+    t.index ["user_id", "project_name", "milestone_type"], name: "idx_on_user_id_project_name_milestone_type_06e1e9487d"
+    t.index ["user_id"], name: "index_project_milestones_on_user_id"
+  end
+
   create_table "project_repo_mappings", force: :cascade do |t|
     t.bigint "user_id", null: false
     t.string "project_name", null: false
@@ -269,6 +291,7 @@
   add_foreign_key "heartbeats", "users"
   add_foreign_key "leaderboard_entries", "leaderboards"
   add_foreign_key "leaderboard_entries", "users"
+  add_foreign_key "project_milestone_kudos", "project_milestones"
   add_foreign_key "project_repo_mappings", "users"
   add_foreign_key "sign_in_tokens", "users"
 end