diff --git a/lib/linters/default.rb b/lib/linters/default.rb
index 28a5fa68..54f4510f 100644
--- a/lib/linters/default.rb
+++ b/lib/linters/default.rb
@@ -1,5 +1,13 @@
 module Linters
   module Default
-
+    #
+    def self.assert_pids(data)
+      data.each_with_index do |d, i|
+        warn Rainbow("WARNING: project number #{i} is missing a pid") unless d.key? 'pid'
+      end
+      pids  = data.map{ |d| d['pid'] }
+      dupes = pids.select { |p| pids.count(p) > 1 }.uniq! || []
+      warn Rainbow("WARNING: The following project pids are not unique!\n#{dupes}") unless dupes.empty?
+    end
   end
 end
diff --git a/lib/linters/projects.rb b/lib/linters/projects.rb
index ae59d73f..e80b0f76 100644
--- a/lib/linters/projects.rb
+++ b/lib/linters/projects.rb
@@ -1,5 +1,24 @@
+require 'rainbow'
+require 'vars'
+
 module Linters
   module Projects
-
+    #
+    def self.assert_people(projects)
+      people = YAML.load_file(Vars::People.yml_file).map { |h| h['pid'] }
+      projects.each do |project|
+        project.dig('pis').each do |pi|
+          warn Rainbow("WARNING: Published project '#{project['pid']}' references nonexisting person '#{pi}'.").orange unless people.include? pi
+        end
+      end
+    end
+    #
+    def self.assert_categories(projects)
+      categories = ['DH Seed Grant Recipient', 'Grad Fellowship Project', 'Other']
+      projects.each do |project|
+        category = project.dig 'category'
+        warn Rainbow("WARNING: Published project '#{project['pid']}' references nonexisting category '#{category}'.").orange unless categories.include? category
+      end
+    end
   end
 end
diff --git a/lib/tasks/fetch/courses.rake b/lib/tasks/fetch/courses.rake
index 3039a034..0a73f699 100644
--- a/lib/tasks/fetch/courses.rake
+++ b/lib/tasks/fetch/courses.rake
@@ -17,5 +17,9 @@ namespace :fetch do
 
     puts "Parsing courses into #{Vars::Courses.yml_file}"
     Utils.write_to_file(data.to_yaml, Vars::Courses.yml_file)
+
+    puts Rainbow("Done ✓").green
+    
+    Rake::Task["lint:courses"].invoke
   end
 end
diff --git a/lib/tasks/fetch/people.rake b/lib/tasks/fetch/people.rake
index 58bc7646..cf603690 100644
--- a/lib/tasks/fetch/people.rake
+++ b/lib/tasks/fetch/people.rake
@@ -20,5 +20,7 @@ namespace :fetch do
     Utils.write_to_file data.to_yaml, Vars::People.yml_file
 
     puts Rainbow("Done ✓").green
+
+    Rake::Task["lint:people"].invoke
   end
 end
diff --git a/lib/tasks/lint/courses.rake b/lib/tasks/lint/courses.rake
new file mode 100644
index 00000000..01df2be8
--- /dev/null
+++ b/lib/tasks/lint/courses.rake
@@ -0,0 +1,13 @@
+require 'rainbow'
+require 'linters/default'
+require 'vars'
+require 'yaml'
+
+namespace :lint do
+  desc 'lint the fetched courses yaml data'
+  task :courses do
+    courses = YAML.load_file Vars::Courses.yml_file
+
+    Linters::Default.assert_pids courses
+  end
+end
diff --git a/lib/tasks/lint/people.rake b/lib/tasks/lint/people.rake
new file mode 100644
index 00000000..7944cd3a
--- /dev/null
+++ b/lib/tasks/lint/people.rake
@@ -0,0 +1,13 @@
+require 'rainbow'
+require 'linters/default'
+require 'vars'
+require 'yaml'
+
+namespace :lint do
+  desc 'lint the fetched people yaml data'
+  task :people do
+    people = YAML.load_file Vars::People.yml_file
+
+    Linters::Default.assert_pids people
+  end
+end
diff --git a/lib/tasks/lint/projects.rake b/lib/tasks/lint/projects.rake
index 93a753d2..3dc60944 100644
--- a/lib/tasks/lint/projects.rake
+++ b/lib/tasks/lint/projects.rake
@@ -7,14 +7,10 @@ require 'yaml'
 namespace :lint do
   desc 'lint the fetched project yaml data'
   task :projects do
-    categories = %w(DH Seed Grant Recipient Grad Fellowship Project Other)
-    people     = YAML.load_file(Vars::People.yml_file).map { |h| h['pid'] }
-    projects   = YAML.load_file Vars::Projects.yml_file
+    projects = YAML.load_file Vars::Projects.yml_file
 
-    projects.each do |project|
-      project.dig('pis').each do |pi|
-        puts Rainbow("WARNING: Project '#{project['pid']}' references nonexisting person '#{pi}'.").magenta unless people.include? pi
-      end
-    end
+    Linters::Default.assert_pids projects
+    Linters::Projects.assert_categories projects
+    Linters::Projects.assert_people projects
   end
 end