diff --git a/Gemfile b/Gemfile
index d4177fc..70c9e97 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,6 @@
 source "https://rubygems.org"
 
-gem "html-proofer", "<4"
+gem "html-proofer"
 gem "jekyll", "~> 4.0"
 gem "jekyll-sass-converter" #, "~>2.0
 
diff --git a/_config.yml b/_config.yml
index 6424f9d..a625101 100644
--- a/_config.yml
+++ b/_config.yml
@@ -11,6 +11,7 @@ plugins:
   - jekyll-paginate
   - jekyll-last-modified-at
   - jekyll-redirect-from
+  - jekyll-seo-tag
 permalink: "/articles/:categories/:title"
 paginate: 5
 paginate_path: "/news/page:num/"
@@ -29,3 +30,6 @@ exclude:
   - build.sh
   - deploy.key
   - deploy.key.enc
+twitter:
+  card: summary
+  username: pybuilder_
diff --git a/_data/authors.yml b/_data/authors.yml
index 944ece2..6cf79ff 100644
--- a/_data/authors.yml
+++ b/_data/authors.yml
@@ -3,7 +3,7 @@ arcivanov:
   email: arcadiy@ivanov.biz
   github: arcivanov
   website: https://www.ivanov.biz/
-  twitter: arcivanov
+  twitter: iamarcivanov
   openhub: arcivanov
   linkedin: arcivanov
 mriehl:
diff --git a/_includes/layout/footer.html b/_includes/layout/footer.html
index e1643d4..6a2a8e1 100644
--- a/_includes/layout/footer.html
+++ b/_includes/layout/footer.html
@@ -11,14 +11,14 @@
     </div>
 </footer>
 
-<script src="//code.jquery.com/jquery-3.4.1.min.js"
+<script src="https://code.jquery.com/jquery-3.4.1.min.js"
         integrity="sha256-CSXorXvZcTkaix6Yvo6HppcZGetbYMGWSFlBw8HfCJo="
         crossorigin="anonymous"></script>
 <script src="/js/jquery-ui-1.10.3.custom.min.js"></script>
-<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"
+<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"
         integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa"
         crossorigin="anonymous"></script>
-<script src="//cdn.rawgit.com/afeld/bootstrap-toc/v0.4.1/dist/bootstrap-toc.min.js"></script>
+<script src="https://cdn.rawgit.com/afeld/bootstrap-toc/v0.4.1/dist/bootstrap-toc.min.js"></script>
 <script src="/js/tabcontent.js"></script>
 <script src="/js/highlight.pack.js"></script>
 
diff --git a/_includes/layout/metaAndStyles.html b/_includes/layout/metaAndStyles.html
index 0839533..fa3d205 100644
--- a/_includes/layout/metaAndStyles.html
+++ b/_includes/layout/metaAndStyles.html
@@ -1,4 +1,4 @@
-<script async src="//www.googletagmanager.com/gtag/js?id=UA-2839506-6"></script>
+<script async src="https://www.googletagmanager.com/gtag/js?id=UA-2839506-6"></script>
 <script>
   window.dataLayer = window.dataLayer || [];
   function gtag(){dataLayer.push(arguments);}
@@ -20,8 +20,8 @@
 <link rel="icon" href="/img/logo.svg"/>
 <link rel="apple-touch-icon" href="/img/logo-apple-touch-icon.png">
 
-<link rel="stylesheet" type="text/css" href="//fonts.googleapis.com/css?family=Oleo+Script:700"/>
-<link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css"
+<link rel="stylesheet" type="text/css" href="https://fonts.googleapis.com/css?family=Oleo+Script:700"/>
+<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css"
       integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
 <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap-theme.min.css"
       integrity="sha384-rHyoN1iRsVXV4nD0JutlnGaslCJuC7uwjduW9SVrLvRYooPp2bWYgmgJQIXwl/Sp" crossorigin="anonymous">
@@ -29,3 +29,5 @@
 <link rel="stylesheet" type="text/css" href="/css/highlightjs.css"/>
 <link rel="stylesheet" type="text/css" href="/css/tabcontent.css"/>
 <link rel="stylesheet" type="text/css" href="/css/styles.css"/>
+
+{% seo %}
diff --git a/_layouts/post.html b/_layouts/post.html
index 3acad2d..1ba6896 100644
--- a/_layouts/post.html
+++ b/_layouts/post.html
@@ -30,21 +30,21 @@ <h1>{{ page.title }}</h1>
                     {% endif %}
                     {% if author.github %}
                     <a rel="author" href="https://github.com/{{ author.github }}" title="{{ author.name }}'s GitHub">
-                        <img src="//external-content.duckduckgo.com/ip/github.com.ico" alt="GitHub Logo"></a>
+                        <img src="https://external-content.duckduckgo.com/ip/github.com.ico" alt="GitHub Logo"></a>
                     {% endif %}
                     {% if author.openhub %}
                     <a rel="author" href="https://www.openhub.net/accounts/{{ author.openhub }}"
                        title="{{ author.name }}'s OpenHub">
-                        <img src="//external-content.duckduckgo.com/ip/openhub.net.ico" alt="OpenHub Logo"></a>
+                        <img src="https://external-content.duckduckgo.com/ip/openhub.net.ico" alt="OpenHub Logo"></a>
                     {% endif %}
                     {% if author.twitter %}
                     <a rel="author" href="https://twitter.com/{{ author.twitter }}" title="{{ author.name }}'s Twitter">
-                        <img src="//external-content.duckduckgo.com/ip/twitter.com.ico" alt="Twitter Logo"></a>
+                        <img src="https://external-content.duckduckgo.com/ip/twitter.com.ico" alt="Twitter Logo"></a>
                     {% endif %}
                     {% if author.linkedin %}
                     <a rel="author" href="https://www.linkedin.com/in/{{ author.linkedin }}/"
                        title="{{ author.name }}'s LinkedIn">
-                        <img src="//external-content.duckduckgo.com/ip/linkedin.com.ico" alt="LinkedIn Logo">
+                        <img src="https://external-content.duckduckgo.com/ip/linkedin.com.ico" alt="LinkedIn Logo">
                     </a>
                     {% endif %}
                     {% endif %}
diff --git a/build.sh b/build.sh
index aac7b94..5c30881 100755
--- a/build.sh
+++ b/build.sh
@@ -3,11 +3,13 @@
 bundle exec jekyll build
 
 bundle exec htmlproofer --allow-hash-href \
-                        --http-status-ignore=429,999 \
-                        --check-html \
-                        --check-opengraph \
-                        --check-favicon \
-                        --assume-extension \
-                        ./_site
+                        --ignore-status-codes=429,999,302 \
+                        --no-check-internal-hash \
+                        --no-check-external-hash \
+                        --no-enforce-https \
+                        --checks Links,Scripts,Images,OpenGraph,Favicon \
+                        --typhoeus='{"followlocation": true, "connecttimeout": 20, "timeout": 60}' \
+                        --hydra='{"max_concurrency": 3}' \
+                        _site
 
 bundle exec jekyll build -c _config.yml,_config-prod.yml
diff --git a/index.html b/index.html
index 33f7720..072699b 100644
--- a/index.html
+++ b/index.html
@@ -1,6 +1,6 @@
 ---
 layout: default
-title: an easy-to-use build automation tool for Python
+title: An easy-to-use build automation tool for Python
 ---
 
 <div class="row">