diff --git a/.circleci/config.yml b/.circleci/config.yml
new file mode 100644
index 0000000000..8ee1d4300c
--- /dev/null
+++ b/.circleci/config.yml
@@ -0,0 +1,210 @@
+#
+# Copyright 2012-2020 The Feign Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+# in compliance with the License. You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software distributed under the License
+# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+# or implied. See the License for the specific language governing permissions and limitations under
+# the License.
+#
+
+# common executors
+executors:
+  java:
+    machine:
+      image: ubuntu-2204:2023.10.1
+
+# common commands
+commands:
+  setup-build-environment:
+    description: 'Setup Java and Maven dependencies with unified caching'
+    steps:
+      - restore_cache:
+          keys:
+            - dependencies-v1-{{ checksum "pom.xml" }}
+      - run:
+          name: 'Check if cache was restored'
+          command: |
+            if [ -d "$HOME/.sdkman/candidates/java/21.0.2-tem" ] && [ -d ~/.m2/repository/io/github/openfeign ]; then
+              echo "Complete cache hit detected - SDKMAN and Maven dependencies available."
+              circleci step halt
+            elif [ -d "$HOME/.sdkman/candidates/java/21.0.2-tem" ]; then
+              echo "SDKMAN cache hit detected, but need to download Maven dependencies."
+            elif [ -d ~/.m2/repository/io/github/openfeign ]; then
+              echo "Maven cache hit detected, but need to install SDKMAN."
+            else
+              echo "No cache hit, setting up complete build environment."
+            fi
+      - run:
+          name: 'Install SDKMAN!'
+          command: |
+            if [ ! -d "$HOME/.sdkman" ]; then
+              curl -s "https://get.sdkman.io" | bash
+            fi
+            source "$HOME/.sdkman/bin/sdkman-init.sh"
+      - run:
+          name: 'Install JDKs (8, 11, 17, 21)'
+          command: |
+            source "$HOME/.sdkman/bin/sdkman-init.sh"
+            jdk_versions=("8.0.382-tem" "11.0.22-tem" "17.0.10-tem" "21.0.2-tem")
+            for jdk_version in "${jdk_versions[@]}"; do
+              if [ ! -d "$HOME/.sdkman/candidates/java/$jdk_version" ]; then
+                echo "n" | sdk install java "$jdk_version" || true
+              fi
+            done
+            sdk default java 21.0.2-tem
+      - run:
+          name: 'Configure Maven Toolchain'
+          command: |
+            mkdir -p ~/.m2
+            cp .circleci/toolchains.xml ~/.m2/toolchains.xml
+      - run:
+          name: 'Download Maven dependencies'
+          command: |
+            source "$HOME/.sdkman/bin/sdkman-init.sh"
+            ./mvnw -ntp -B \
+              org.apache.maven.plugins:maven-dependency-plugin:3.8.1:go-offline \
+              de.qaware.maven:go-offline-maven-plugin:1.2.8:resolve-dependencies \
+              -T2 -pl -:feign-benchmark
+      - save_cache:
+          paths:
+            - ~/.sdkman
+            - ~/.m2
+          key: dependencies-v1-{{ checksum "pom.xml" }}
+  restore-build-environment:
+    description: 'Restore cached build environment'
+    steps:
+      - restore_cache:
+          keys:
+            - dependencies-v1-{{ checksum "pom.xml" }}
+  verify-formatting:
+    steps:
+      - run:
+          name: 'Verify formatting'
+          command: |
+            scripts/no-git-changes.sh
+  configure-gpg:
+    steps:
+      - run:
+          name: 'Configure GPG keys'
+          command: |
+            echo -e "$GPG_KEY" | gpg --batch --no-tty --import --yes
+  nexus-deploy:
+    steps:
+      - run:
+          name: 'Deploy Core Modules Sonatype'
+          command: |
+            source "$HOME/.sdkman/bin/sdkman-init.sh"
+            ./mvnw -ntp -nsu -s .circleci/settings.xml -P release -pl -:feign-benchmark -DskipTests=true deploy
+
+# our job defaults
+defaults: &defaults
+  working_directory: ~/feign
+  environment:
+    # Customize the JVM maximum heap limit
+    MAVEN_OPTS: -Xmx3200m
+
+# branch filters
+master-only: &master-only
+  branches:
+    only: master
+
+tags-only: &tags-only
+  branches:
+    ignore: /.*/
+  tags:
+    only: /.*/
+
+all-branches: &all-branches
+  branches:
+    ignore: master
+  tags:
+    ignore: /.*/
+
+version: 2.1
+
+jobs:
+  setup-build-environment:
+    executor:
+      name: java
+    <<: *defaults
+    steps:
+      - checkout
+      - setup-build-environment
+
+  test:
+    executor:
+      name: java
+    <<: *defaults
+    steps:
+      - checkout
+      - restore-build-environment
+      - run:
+          name: 'Test'
+          command: |
+            source "$HOME/.sdkman/bin/sdkman-init.sh"
+            ./mvnw -ntp -B verify
+      - verify-formatting
+
+  deploy:
+    executor:
+      name: java
+    <<: *defaults
+    steps:
+      - checkout
+      - restore-build-environment
+      - configure-gpg
+      - nexus-deploy
+
+workflows:
+  version: 2
+  build:
+    jobs:
+      - setup-build-environment:
+          name: 'setup-environment'
+          filters:
+            <<: *all-branches
+      - test:
+          name: 'pr-build'
+          requires:
+            - 'setup-environment'
+          filters:
+            <<: *all-branches
+
+  snapshot:
+    jobs:
+      - setup-build-environment:
+          name: 'setup-environment-snapshot'
+          filters:
+            <<: *master-only
+      - test:
+          name: 'snapshot'
+          requires:
+            - 'setup-environment-snapshot'
+          filters:
+            <<: *master-only
+      - deploy:
+          name: 'deploy snapshot'
+          requires:
+            - 'snapshot'
+          context: Sonatype
+          filters:
+            <<: *master-only
+
+  release:
+    jobs:
+      - setup-build-environment:
+          name: 'setup-environment-release'
+          filters:
+            <<: *tags-only
+      - deploy:
+          name: 'release to maven central'
+          requires:
+            - 'setup-environment-release'
+          context: Sonatype
+          filters:
+            <<: *tags-only
\ No newline at end of file
diff --git a/.circleci/settings.xml b/.circleci/settings.xml
new file mode 100644
index 0000000000..b7f976093f
--- /dev/null
+++ b/.circleci/settings.xml
@@ -0,0 +1,38 @@
+<!--
+
+    Copyright 2012-2019 The Feign Authors
+
+    Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+    in compliance with the License. You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software distributed under the License
+    is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+    or implied. See the License for the specific language governing permissions and limitations under
+    the License.
+
+-->
+<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
+                          http://maven.apache.org/xsd/settings-1.0.0.xsd">
+  <servers>
+    <server>
+      <id>ossrh</id>
+      <username>${env.SONATYPE_USER}</username>
+      <password>${env.SONATYPE_PASSWORD}</password>
+    </server>
+  </servers>
+  <profiles>
+    <profile>
+      <id>ossrh</id>
+      <activation>
+        <activeByDefault>true</activeByDefault>
+      </activation>
+      <properties>
+        <gpg.passphrase>${env.GPG_PASSPHRASE}</gpg.passphrase>
+      </properties>
+    </profile>
+  </profiles>
+</settings>
\ No newline at end of file
diff --git a/.circleci/toolchains.xml b/.circleci/toolchains.xml
new file mode 100644
index 0000000000..d6ef9d38d3
--- /dev/null
+++ b/.circleci/toolchains.xml
@@ -0,0 +1,53 @@
+<!--
+
+    Copyright 2012-2019 The Feign Authors
+
+    Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+    in compliance with the License. You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software distributed under the License
+    is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+    or implied. See the License for the specific language governing permissions and limitations under
+    the License.
+
+-->
+<toolchains>
+    <toolchain>
+        <type>jdk</type>
+        <provides>
+            <version>1.8</version>
+        </provides>
+        <configuration>
+            <jdkHome>/home/circleci/.sdkman/candidates/java/8.0.382-tem</jdkHome>
+        </configuration>
+    </toolchain>
+    <toolchain>
+        <type>jdk</type>
+        <provides>
+            <version>11</version>
+        </provides>
+        <configuration>
+            <jdkHome>/home/circleci/.sdkman/candidates/java/11.0.22-tem</jdkHome>
+        </configuration>
+    </toolchain>
+    <toolchain>
+        <type>jdk</type>
+        <provides>
+            <version>17</version>
+        </provides>
+        <configuration>
+            <jdkHome>/home/circleci/.sdkman/candidates/java/17.0.10-tem</jdkHome>
+        </configuration>
+    </toolchain>
+    <toolchain>
+        <type>jdk</type>
+        <provides>
+            <version>21</version>
+        </provides>
+        <configuration>
+            <jdkHome>/home/circleci/.sdkman/candidates/java/21.0.2-tem</jdkHome>
+        </configuration>
+    </toolchain>
+</toolchains>
\ No newline at end of file
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
deleted file mode 100644
index 77ea2f5a7b..0000000000
--- a/.github/workflows/build.yml
+++ /dev/null
@@ -1,96 +0,0 @@
-#
-# Copyright 2012-2020 The Feign Authors
-#
-# Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
-# in compliance with the License. You may obtain a copy of the License at
-#
-# http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software distributed under the License
-# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
-# or implied. See the License for the specific language governing permissions and limitations under
-# the License.
-#
-name: Build
-
-on:
-  push:
-    branches:
-      - master
-    tags:
-      - '*'  # Runs on all new tags
-  pull_request:
-
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    timeout-minutes: 30
-    env:
-      # Customize the JVM maximum heap limit
-      MAVEN_OPTS: -Xmx3200m
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-        with:
-          ref: ${{ github.event.pull_request.head.ref }}
-          repository: ${{ github.event.pull_request.head.repo.full_name }}
-
-      - name: Cache local Maven repository
-        uses: actions/cache@v3
-        continue-on-error: true
-        with:
-          path: ~/.m2
-          key: ${{ runner.os }}-maven-${{ matrix.language }} ${{ hashFiles('**/pom.xml') }}
-          restore-keys: |
-            ${{ runner.os }}-maven-${{ matrix.language }}
-            ${{ runner.os }}-maven-
-
-      - name: Cache SDKMAN JDKs
-        uses: actions/cache@v4
-        with:
-          path: ~/.sdkman
-          key: sdkman-java-${{ runner.os }}-${{ hashFiles('~/.m2/toolchains.xml') }}
-          restore-keys: sdkman-java-${{ runner.os }}-
-
-      - name: Install SDKMAN!
-        run: |
-          if [ ! -d "$HOME/.sdkman" ]; then
-            curl -s "https://get.sdkman.io" | bash
-          fi
-          source "$HOME/.sdkman/bin/sdkman-init.sh"
-
-      - name: Install JDKs (8, 11, 17, 21)
-        run: |
-          source "$HOME/.sdkman/bin/sdkman-init.sh"
-          jdk_versions=("8.0.382-tem" "11.0.22-tem" "17.0.10-tem" "21.0.2-tem")
-          for jdk_version in "${jdk_versions[@]}"; do
-            if [ ! -d "$HOME/.sdkman/candidates/java/$jdk_version" ]; then
-              yes n | sdk install java "$jdk_version"
-            fi
-          done
-          sdk default java 21.0.2-tem
-
-      - name: Configure Maven Toolchain
-        run: |
-          mkdir -p ~/.m2
-          cp .github/files/toolchains.xml ~/.m2/toolchains.xml
-
-      - name: Download dependencies only
-        run: ./mvnw -ntp -B org.apache.maven.plugins:maven-dependency-plugin:3.8.1:go-offline de.qaware.maven:go-offline-maven-plugin:1.2.8:resolve-dependencies -fn
-
-      - name: Build
-        run: ./mvnw -ntp -B clean install
-
-      - name: Verify formatting
-        run: scripts/no-git-changes.sh
-
-      - name: Nexus deploy
-        if: github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/tags/')
-        env:
-          GPG_KEY: ${{ secrets.GPG_KEY }}
-          SONATYPE_USER: ${{ secrets.SONATYPE_USER }}
-          SONATYPE_PASSWORD: ${{ secrets.SONATYPE_PASSWORD }}
-        run: |
-          cp .github/files/settings.xml ~/.m2/settings.xml
-          echo -e "$GPG_KEY" | gpg --batch --no-tty --import --yes
-          ./mvnw -ntp -nsu -P release -pl -:feign-benchmark -DskipTests=true deploy -T1