diff --git a/lib/fic_tracker/util/cache.rb b/lib/fic_tracker/util/cache.rb
index 705a59f..11dc5bb 100644
--- a/lib/fic_tracker/util/cache.rb
+++ b/lib/fic_tracker/util/cache.rb
@@ -2,9 +2,9 @@
 
 begin
   require 'cbor'
-rescue LoadError
-  require 'json'
+rescue LoadError # Load CBOR if possible
 end
+require 'json'
 
 module FicTracker::Util
   class Cache
@@ -26,6 +26,9 @@ module FicTracker::Util
       when :redis, 'redis'
         require_relative 'cache/redis'
         cache = CacheImpl::Redis.new(**options)
+      when :s3, 'S3'
+        require_relative 'cache/s3'
+        cache = CacheImpl::Redis.new(**options)
       when :none, 'none', nil
         require_relative 'cache/dummy'
         cache = CacheImpl::Dummy.new
@@ -127,8 +130,8 @@ module FicTracker::Util
 
     def best_encoder?(data)
       pod_encoder = :none if data.is_a?(String)
-      pod_encoder ||= :cbor if Object.const_defined?(:CBOR)
-      pod_encoder ||= :json if Object.const_defined?(:JSON)
+      pod_encoder ||= :cbor if Object.const_defined?(:CBOR) && data.respond_to?(:to_cbor)
+      pod_encoder ||= :json if Object.const_defined?(:JSON) && data.respond_to?(:to_json)
       pod_encoder ||= :marshal
       return pod_encoder if is_pod?(data)
 
@@ -139,11 +142,9 @@ module FicTracker::Util
       encode ||= @encoder
       encode ||= best_encoder?(data)
 
-      flags = 0
+      flags = ENCODING_NONE
       case encode
       when :none
-        data = data
-        flags |= ENCODING_NONE
       when :marshal
         data = Marshal.dump(data)
         flags |= ENCODING_MARSHAL
diff --git a/lib/fic_tracker/util/cache/database.rb b/lib/fic_tracker/util/cache/database.rb
index d3466b0..e328fc6 100644
--- a/lib/fic_tracker/util/cache/database.rb
+++ b/lib/fic_tracker/util/cache/database.rb
@@ -12,8 +12,8 @@ module FicTracker::Util::CacheImpl
     end
 
     def expire
-      @dataset.where { Sequel::CURRENT_DATE >= expire_at }.update(expired: true)
       dataset_expired.delete
+      @dataset.where { Sequel::CURRENT_DATE >= expire_at }.update(expired: true)
     end
 
     def has?(key)
diff --git a/lib/fic_tracker/util/cache/file.rb b/lib/fic_tracker/util/cache/file.rb
index ea13ed8..f6d92c8 100644
--- a/lib/fic_tracker/util/cache/file.rb
+++ b/lib/fic_tracker/util/cache/file.rb
@@ -7,7 +7,7 @@ module FicTracker::Util::CacheImpl
   # A filesystem-backed in-memory cache
   class File < Base
     def initialize(dir: nil)
-      @dir = dir || Dir.mktmpdir('ficagg')
+      @dir = dir || Dir.mktmpdir('fictrack')
 
       @internal = Memory.new
     end
@@ -88,7 +88,7 @@ module FicTracker::Util::CacheImpl
 
     def meta_valid?(meta)
       return true unless meta[:ttl]
-      
+
       Time.now < Time.at(meta[:ttl])
     end
 
diff --git a/lib/fic_tracker/util/cache/s3.rb b/lib/fic_tracker/util/cache/s3.rb
new file mode 100644
index 0000000..21677a8
--- /dev/null
+++ b/lib/fic_tracker/util/cache/s3.rb
@@ -0,0 +1,87 @@
+# frozen_string_literal: true
+
+require 's3-light'
+
+class S3Light::Object
+  def read
+    response = client.with_connection do |connection|
+      connection.make_request(:get, "/#{bucket.name}/#{key}")
+    end
+
+    response.body.to_s
+  end
+end
+
+module FicTracker::Util::CacheImpl
+  # A cache using an S3 bucket
+  class S3 < Base
+    def initialize(access_key:, secret_key:, bucket:, **s3)
+      @connection = nil # ...
+      @bucket = nil # ...
+      @objects = @bucket.objects
+
+      load_bucket!
+    end
+
+    def expire
+      to_destroy = @objects.all.reject do |obj|
+        obj.key.end_with?('.meta') || check_meta(obj.key)
+      end
+      return if to_destroy.empty?
+
+      @objects.destroy_batch keys: to_destroy.map(&:key)
+    end
+
+    def has?(key)
+      return check_meta key
+    end
+
+    def get(key)
+      return nil unless check_meta key
+
+      @objects.find_by(key:).read
+    end
+
+    def set(key, value, expiry = nil)
+      expiry = expiry >= 0 ? Time.now + expiry : nil if expiry.is_a?(Numeric)
+      expiry = nil if expiry.is_a?(Numeric)
+      meta = {
+        key: key,
+        ttl: expiry&.to_i
+      }.compact.to_json
+
+      @objects.new(key:, input: value).save!
+      @objects.new(key: "#{key}.meta", input: meta.to_json).save!
+
+      value
+    end
+
+    def delete(key)
+      @objects.destroy_batch keys: [
+        key,
+        "#{key}.meta"
+      ]
+      nil
+    end
+
+    def clear
+      to_destroy = @objects.all.map(&:key)
+      return if to_destroy.empty?
+
+      @objects.destroy_batch keys: to_destroy
+      nil
+    end
+
+    private
+
+    def check_meta(key)
+      meta_key = "#{key}.meta"
+      return true unless @objects.exists? meta_key
+
+      meta = JSON.parse(@objects.find_by(key: meta_key))
+      return true unless meta[:ttl]
+
+      Time.now < Time.at(meta[:ttl])
+    end
+  end
+end