diff --git a/.claude/skills/check-ci/SKILL.md b/.claude/skills/check-ci/SKILL.md
new file mode 100644
index 0000000..a00a156
--- /dev/null
+++ b/.claude/skills/check-ci/SKILL.md
@@ -0,0 +1,50 @@
+---
+name: check-ci
+description: Fetch and report CI results for a silk PR. Use when the user asks to investigate, address, or fix CI failures, or refers to a PR without specifying what's broken.
+---
+
+Always fetch the CI result JSON before reading code or proposing fixes.
+
+## Determining PR, sha, and workflow name
+
+**From a Praktika report URL** (e.g. `https://silk-artifacts-eu-north-1.s3.amazonaws.com/json.html?PR=12&sha=abc123&name_0=Pull%20Request%20CI`):
+- Extract `PR`, `sha`, `name_0` from query params
+- Normalize `name_0`: lowercase + spaces → underscores (e.g. `"Pull Request CI"` → `"pull_request_ci"`)
+
+**From a bare PR number:**
+- Run `gh pr view {PR} --json headRefOid --jq '.headRefOid'` to get the latest sha
+- Use `pull_request_ci` as the normalized workflow name
+
+## Building the JSON URL
+
+```
+https://silk-artifacts-eu-north-1.s3.amazonaws.com/PRs/{PR}/{sha}/{normalized}/result_{normalized}.json
+```
+
+Fetch this URL with WebFetch.
+
+## Result structure
+
+The JSON is a serialized `praktika.Result`:
+
+```
+{
+  "name": str,
+  "status": str,       # OK | FAIL | ERROR | SKIPPED | UNKNOWN | XFAIL | XPASS | PENDING | RUNNING | DROPPED
+  "start_time": float?,
+  "duration": float?,
+  "info": str,
+  "results": [...],    # nested Result objects, same shape, recursive
+  "files": [...],
+  "links": [...],
+  "ext": {
+    "labels": [{"name": str, "link": str?, "hint": str?}, ...],
+    "warnings": [...],
+    "errors": [...],
+    "report_url": str?,
+    ...
+  }
+}
+```
+
+Walk the `results` tree recursively to find all failing jobs and sub-jobs. Use the `info` field of failing nodes as the primary signal for what went wrong before touching any code.
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 028416c..bc3fcce 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -3,8 +3,6 @@ name: CI
 on:
   push:
     branches: [main]
-  pull_request:
-    branches: [main]
   workflow_dispatch:
 
 jobs:
diff --git a/.gitignore b/.gitignore
index 4148b04..3927231 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,4 @@
 .tools/
 build/
 compile_commands.json
+ci/tmp/
diff --git a/ci/infrastructure/projects.py b/ci/infrastructure/projects.py
new file mode 100644
index 0000000..cd8c56b
--- /dev/null
+++ b/ci/infrastructure/projects.py
@@ -0,0 +1,259 @@
+from ci.settings.settings import PROJECT_NAME, PROJECT_SLUG, PRAKTIKA_BASE_VENV
+from praktika.infrastructure import Components, Storage, VPC
+from praktika.infrastructure.cloud import CloudInfrastructure
+
+
+# until published in pip
+_PRAKTIKA_WHL = "https://praktika-artifacts-eu-north-1.s3.amazonaws.com/packages/praktika-0.1.3-py3-none-any.whl"
+_PRAKTIKA_CONTROLLER_WHL = "https://praktika-artifacts-eu-north-1.s3.amazonaws.com/packages/praktika_controller-0.1.1-py3-none-any.whl"
+
+
+def _runner_user_data():
+    return "\n".join(
+        [
+            "#!/usr/bin/env bash",
+            "set -xeuo pipefail",
+            "",
+            "# Force-reinstall praktika so the runner uses the version pinned here",
+            "# rather than whatever was baked into the AMI at image-build time.",
+            (
+                f"/opt/praktika/base-venvs/{PRAKTIKA_BASE_VENV}/bin/python "
+                f"-m pip install --force-reinstall {_PRAKTIKA_WHL}"
+            ),
+            "# Add any host customization you need above this line.",
+            "/usr/local/bin/praktika-configure-cloudwatch-agent",
+            "/opt/aws/amazon-cloudwatch-agent/bin/amazon-cloudwatch-agent-ctl -a fetch-config -m ec2 -c file:/etc/praktika/amazon-cloudwatch-agent.json -s",
+            "systemctl enable --now praktika-controller",
+            "",
+        ]
+    )
+
+
+def _silk_ci_dependencies_component():
+    return {
+        "name": "silk-ci-dependencies",
+        "platform": "Linux",
+        "description": "Install Silk CI toolchains and build dependencies",
+        "commands": [
+            "export DEBIAN_FRONTEND=noninteractive",
+            (
+                "wget -qO- https://apt.llvm.org/llvm-snapshot.gpg.key "
+                "> /etc/apt/trusted.gpg.d/apt.llvm.org.asc"
+            ),
+            (
+                ". /etc/os-release && echo \"deb http://apt.llvm.org/"
+                "${VERSION_CODENAME}/ llvm-toolchain-${VERSION_CODENAME}-21 main\" "
+                "> /etc/apt/sources.list.d/llvm-21.list"
+            ),
+            (
+                "wget -qO- https://apt.kitware.com/keys/"
+                "kitware-archive-latest.asc > /etc/apt/trusted.gpg.d/kitware.asc"
+            ),
+            (
+                ". /etc/os-release && echo \"deb https://apt.kitware.com/ubuntu/ "
+                "${VERSION_CODENAME} main\" > /etc/apt/sources.list.d/kitware.list"
+            ),
+            (
+                "DEBIAN_FRONTEND=noninteractive apt-get -o DPkg::Lock::Timeout=60 "
+                "install -y software-properties-common"
+            ),
+            "add-apt-repository -y ppa:ubuntu-toolchain-r/test",
+            "apt-get -o DPkg::Lock::Timeout=60 update -q",
+            (
+                "DEBIAN_FRONTEND=noninteractive apt-get -o DPkg::Lock::Timeout=60 "
+                "install -y clang-21 clang-format-21 llvm-21 cmake "
+                "libstdc++-13-dev ninja-build ccache libboost-dev "
+                "libdouble-conversion-dev libelf-dev zlib1g-dev"
+            ),
+        ],
+    }
+
+
+def _silk_ci_image_test_component():
+    return Components.create_image_test_component(
+        name="silk-ci-image-test",
+        description="Validate Silk CI toolchains and build dependencies",
+        commands=[
+            "test -d /opt/praktika/work",
+            "test -w /opt/praktika/work",
+            "test -x /usr/bin/clang-21",
+            "test -x /usr/bin/clang-format-21",
+            "test -x /usr/bin/cmake",
+            "test -x /usr/bin/ninja",
+            "test -x /usr/bin/ccache",
+            "clang-21 --version",
+            "clang-format-21 --version",
+            "cmake --version",
+            "ninja --version",
+            "ccache --version",
+            (
+                "for package in llvm-21 libstdc++-13-dev libboost-dev "
+                "libdouble-conversion-dev libelf-dev zlib1g-dev; do "
+                "dpkg-query -W -f='${Status}\\n' \"$package\" "
+                "| grep -qx 'install ok installed'; done"
+            ),
+        ],
+    )
+
+
+def _praktika_controller_image_test_component():
+    controller = "praktika-controller"
+    start_script = f"/usr/local/bin/${{controller}}-start"
+    service_unit = f"/etc/systemd/system/${{controller}}.service"
+    return Components.create_image_test_component(
+        name="silk-praktika-controller-image-test",
+        description="Validate Praktika controller runtime and boot wiring",
+        commands=[
+            f"controller={controller}; command -v \"$controller\"",
+            (
+                f"controller={controller}; "
+                "python3.12 -m pip show \"$controller\""
+            ),
+            f"controller={controller}; test -x {start_script}",
+            f"controller={controller}; bash -n {start_script}",
+            f"controller={controller}; test -f {service_unit}",
+            (
+                f"controller={controller}; "
+                f"grep -qx \"ExecStart={start_script}\" {service_unit}"
+            ),
+            (
+                f"controller={controller}; "
+                f"grep -qx \"StandardOutput=append:/var/log/${{controller}}.log\" {service_unit}"
+            ),
+            (
+                f"controller={controller}; "
+                f"grep -qx \"StandardError=append:/var/log/${{controller}}.log\" {service_unit}"
+            ),
+            (
+                "test -x /usr/local/bin/praktika-configure-cloudwatch-agent "
+                "&& bash -n /usr/local/bin/praktika-configure-cloudwatch-agent"
+            ),
+            "test -x /opt/aws/amazon-cloudwatch-agent/bin/amazon-cloudwatch-agent-ctl",
+        ],
+    )
+
+
+def _silk_ci_image_components():
+    return [
+        _silk_ci_dependencies_component(),
+        _silk_ci_image_test_component(),
+        _praktika_controller_image_test_component(),
+    ]
+
+
+def _image_builders():
+    image_recipe_version = "1.0.7"
+    prebuilt_venvs = [
+        Components.create_praktika_venv_config(
+            PRAKTIKA_BASE_VENV,
+            "0.1.3",
+        ),
+    ]
+    return [
+        Components.create_ubuntu_image_builder_config(
+            name="ci-arm64-image",
+            version=image_recipe_version,
+            controller_package=_PRAKTIKA_CONTROLLER_WHL,
+            prebuilt_venvs=prebuilt_venvs,
+            instance_types=["t4g.small"],
+            components=_silk_ci_image_components(),
+        ),
+        Components.create_ubuntu_image_builder_config(
+            name="ci-x86_64-image",
+            version=image_recipe_version,
+            controller_package=_PRAKTIKA_CONTROLLER_WHL,
+            prebuilt_venvs=prebuilt_venvs,
+            instance_types=["t3.small"],
+            components=_silk_ci_image_components(),
+        ),
+    ]
+
+
+_GH_TOKEN_MINTER = Components.GitHubTokenMinter(
+    repositories=[PROJECT_NAME],
+)
+_IMAGE_BUILDERS = _image_builders()
+_IMAGE_BUILDERS_BY_NAME = {builder.name: builder for builder in _IMAGE_BUILDERS}
+
+PROJECTS = [
+    CloudInfrastructure.Config(
+        name=PROJECT_NAME,
+        min_praktika_version="0.1.3",
+        vpcs=[
+            VPC.Config(
+                subnets=[
+                    VPC.Subnet(availability_zone="eu-north-1a"),
+                ],
+            )
+        ],
+        storages=[
+            Storage.Config(
+                name="artifacts-eu-north-1",
+                retention_days=30,
+                public=True,
+            ),
+        ],
+        report_pages=[Components.report_page_config],
+        image_builders=_IMAGE_BUILDERS,
+        github_token_minters=[_GH_TOKEN_MINTER],
+        orchestrator_pool=Components.OrchestratorPool(
+            instance_type="t4g.small",
+            scaling=Components.OrchestratorPool.Scaling.Auto,
+            size=0,
+            max_size=50,
+            capacity_reserve=1,
+            volume_size_gb=100,
+            image_builder=_IMAGE_BUILDERS_BY_NAME["ci-arm64-image"],
+            ext={"allowed_push_branches": ["main", "add-praktika-ci-config"]}
+        ),
+        runner_pools=[
+            Components.RunnerPool(
+                name="arm-small",
+                instance_type="t4g.medium",
+                scaling=Components.RunnerPool.Scaling.Auto,
+                size=0,
+                max_size=50,
+                volume_size_gb=100,
+                image_builder=_IMAGE_BUILDERS_BY_NAME["ci-arm64-image"],
+                user_data=_runner_user_data(),
+            ),
+            Components.RunnerPool(
+                name="amd-small",
+                instance_type="t3.medium",
+                scaling=Components.RunnerPool.Scaling.Auto,
+                size=0,
+                max_size=50,
+                volume_size_gb=100,
+                image_builder=_IMAGE_BUILDERS_BY_NAME["ci-x86_64-image"],
+                user_data=_runner_user_data(),
+            ),
+            Components.RunnerPool(
+                name="arm-medium",
+                instance_type="c7g.4xlarge",
+                scaling=Components.RunnerPool.Scaling.Auto,
+                size=0,
+                max_size=50,
+                volume_size_gb=100,
+                image_builder=_IMAGE_BUILDERS_BY_NAME["ci-arm64-image"],
+            ),
+            Components.RunnerPool(
+                name="arm-large",
+                instance_type="c7g.8xlarge",
+                scaling=Components.RunnerPool.Scaling.Auto,
+                size=0,
+                max_size=50,
+                volume_size_gb=100,
+                image_builder=_IMAGE_BUILDERS_BY_NAME["ci-arm64-image"],
+            ),
+            Components.RunnerPool(
+                name="amd-medium",
+                instance_type="c7a.4xlarge",
+                scaling=Components.RunnerPool.Scaling.Auto,
+                size=0,
+                max_size=50,
+                volume_size_gb=100,
+                image_builder=_IMAGE_BUILDERS_BY_NAME["ci-x86_64-image"],
+            ),
+        ],
+    )
+]
diff --git a/ci/jobs/fmt_job.py b/ci/jobs/fmt_job.py
new file mode 100644
index 0000000..93245f6
--- /dev/null
+++ b/ci/jobs/fmt_job.py
@@ -0,0 +1,7 @@
+from praktika.result import Result
+
+if __name__ == "__main__":
+    Result.from_commands_run(
+        name="Check formatting",
+        command=["./bb fmt --check"],
+    ).complete_job()
diff --git a/ci/jobs/init_submodules.py b/ci/jobs/init_submodules.py
new file mode 100644
index 0000000..81010ed
--- /dev/null
+++ b/ci/jobs/init_submodules.py
@@ -0,0 +1,52 @@
+import subprocess
+
+from praktika.info import Info
+
+
+COMMON_SUBMODULES = [
+    "contrib/benchmark",
+    "contrib/bpftool",
+    "contrib/cxxopts",
+    "contrib/googletest",
+    "contrib/libbacktrace",
+    "contrib/libbpf",
+    "contrib/librseq",
+    "contrib/liburing",
+]
+
+EXTRA_SUBMODULES_BY_BUILD = {
+    "release": ["contrib/poco", "contrib/jemalloc"],
+    "tsan": ["contrib/poco"],
+    "msan": ["contrib/llvm-project"],
+}
+
+
+def run(*args):
+    print("+", " ".join(args), flush=True)
+    subprocess.run(args, check=True)
+
+
+def checkout_submodules(paths):
+    run(
+        "git",
+        "submodule",
+        "update",
+        "--init",
+        "--no-fetch",
+        "--depth=1",
+        "--jobs",
+        "8",
+        *paths,
+    )
+
+
+if __name__ == "__main__":
+    job_name = Info().job_name
+
+    run("git", "submodule", "sync")
+    checkout_submodules(COMMON_SUBMODULES)
+
+    for build, paths in EXTRA_SUBMODULES_BY_BUILD.items():
+        if f"({build})" in job_name:
+            checkout_submodules(paths)
+            break
diff --git a/ci/jobs/test_job.py b/ci/jobs/test_job.py
new file mode 100644
index 0000000..97a6582
--- /dev/null
+++ b/ci/jobs/test_job.py
@@ -0,0 +1,68 @@
+import sys
+
+from praktika.result import Result
+
+_CONFIGS = {
+    "coverage": {
+        "test": "./bb -b debug test --coverage",
+    },
+    "release": {
+        "configure": "./bb -b release configure --build-poco --build-jemalloc",
+        "test": "./bb -b release test",
+        "bench": "./bb -b release bench",
+        "perf": "./bb -v -b release perf file net http",
+    },
+    "tsan": {
+        "configure": "./bb -b release -s thread configure --build-poco",
+        "test": "./bb -b release -s thread test",
+        "bench": "./bb -b release -s thread bench",
+        "perf": "./bb -v -b release -s thread perf file net http",
+    },
+    "asan": {
+        "test": "./bb -b release -s address test",
+    },
+    "ubsan": {
+        "test": "./bb -b release -s undefined test",
+    },
+    "msan": {
+        "test": "./bb -b release -s memory test",
+    },
+}
+
+if __name__ == "__main__":
+    build = sys.argv[1]
+    config = _CONFIGS[build]
+    results = []
+
+    if "configure" in config:
+        results.append(
+            Result.from_commands_run(
+                name="Configure",
+                command=[config["configure"]],
+            )
+        )
+
+    results.append(
+        Result.from_commands_run(
+            name="Build and test",
+            command=[config["test"]],
+        )
+    )
+
+    if "bench" in config:
+        results.append(
+            Result.from_commands_run(
+                name="Bench",
+                command=[config["bench"]],
+            )
+        )
+
+    if "perf" in config:
+        results.append(
+            Result.from_commands_run(
+                name="Perf",
+                command=[config["perf"]],
+            )
+        )
+
+    Result.create_from(results=results).complete_job()
diff --git a/ci/settings/settings.py b/ci/settings/settings.py
new file mode 100644
index 0000000..3895e57
--- /dev/null
+++ b/ci/settings/settings.py
@@ -0,0 +1,31 @@
+class RunnerLabels:
+    SMALL_ARM = "arm-small"
+    SMALL_AMD = "amd-small"
+    MEDIUM_ARM = "arm-medium"
+    MEDIUM_AMD = "amd-medium"
+    LARGE_ARM = "arm-large"
+
+
+PROJECT_NAME = "silk"
+PROJECT_SLUG = "silk"
+MAIN_BRANCH = "main"
+
+CI_CONFIG_RUNS_ON = [RunnerLabels.SMALL_ARM]
+
+AWS_REGION = "eu-north-1"
+AWS_ACCOUNT_ID = "420943511422"
+AWS_PROFILE = "Box"
+
+S3_ARTIFACT_BUCKET = f"{PROJECT_SLUG}-artifacts-{AWS_REGION}"
+S3_REPORT_BUCKET = S3_ARTIFACT_BUCKET
+CACHE_S3_PATH = f"{S3_ARTIFACT_BUCKET}/ci_cache"
+ENABLE_SUBMODULE_CACHE = True
+S3_BUCKET_TO_HTTP_ENDPOINT = {
+    S3_REPORT_BUCKET: f"{S3_REPORT_BUCKET}.s3.amazonaws.com",
+}
+
+USE_CUSTOM_GH_AUTH = True
+GH_AUTH_LAMBDA_NAME = f"{PROJECT_SLUG}-gh-token"
+GH_AUTH_LAMBDA_REGION = AWS_REGION
+PRAKTIKA_BASE_VENV = "praktika-runtime-0.1.2"
+
diff --git a/ci/workflows/main_ci.py b/ci/workflows/main_ci.py
new file mode 100644
index 0000000..4e6d151
--- /dev/null
+++ b/ci/workflows/main_ci.py
@@ -0,0 +1,20 @@
+from praktika import Job, Workflow
+from ci.settings.settings import RunnerLabels
+
+
+WORKFLOWS = [
+    Workflow.Config(
+        name="Main CI",
+        event=Workflow.Event.PUSH,
+        branches=["main", "add-praktika-ci-config"],
+        jobs=[
+            Job.Config(
+                name="Hello World Test",
+                runs_on=[RunnerLabels.SMALL_ARM],
+                command='python3 -c \'print("hello world")\'',
+            ),
+        ],
+        enable_report=True,
+        enable_exit_code_result=True,
+    )
+]
diff --git a/ci/workflows/pull_request.py b/ci/workflows/pull_request.py
new file mode 100644
index 0000000..1f4a21e
--- /dev/null
+++ b/ci/workflows/pull_request.py
@@ -0,0 +1,71 @@
+from praktika import Job, Workflow
+from ci.settings.settings import RunnerLabels
+
+FMT_JOB = Job.Config(
+    name="Formatting",
+    runs_on=[RunnerLabels.SMALL_ARM],
+    command="python3 ./ci/jobs/fmt_job.py",
+    digest_config=Job.CacheDigestConfig(
+        include_paths=["src", "include"],
+    ),
+)
+
+_TEST_DIGEST = Job.CacheDigestConfig(
+    include_paths=[
+        "src",
+        "include",
+        "CMakeLists.txt",
+        "CMakePresets.json",
+        "bb",
+        "ci/jobs/init_submodules.py",
+    ],
+    with_git_submodules=True,
+)
+
+_CHECKOUT_TEST_SUBMODULES = "python3 ./ci/jobs/init_submodules.py"
+
+_TEST_ARM = Job.Config(
+    name="Test ARM",
+    runs_on=[RunnerLabels.MEDIUM_ARM],
+    command="python3 ./ci/jobs/test_job.py {PARAMETER}",
+    needs_submodules=True,
+    pre_hooks=[_CHECKOUT_TEST_SUBMODULES],
+    timeout=2 * 3600,
+    digest_config=_TEST_DIGEST,
+)
+
+_TEST_AMD = Job.Config(
+    name="Test AMD",
+    runs_on=[RunnerLabels.MEDIUM_AMD],
+    command="python3 ./ci/jobs/test_job.py {PARAMETER}",
+    needs_submodules=True,
+    pre_hooks=[_CHECKOUT_TEST_SUBMODULES],
+    timeout=2 * 3600,
+    digest_config=_TEST_DIGEST,
+)
+
+_BUILD_VARIANTS = [
+    Job.ParamSet(parameter="coverage"),
+    Job.ParamSet(parameter="release"),
+    Job.ParamSet(parameter="tsan"),
+    Job.ParamSet(parameter="asan"),
+    Job.ParamSet(parameter="ubsan"),
+    Job.ParamSet(parameter="msan"),
+]
+
+WORKFLOWS = [
+    Workflow.Config(
+        name="Pull Request CI",
+        event=Workflow.Event.PULL_REQUEST,
+        base_branches=["main"],
+        jobs=[
+            FMT_JOB,
+            *_TEST_ARM.parametrize(*_BUILD_VARIANTS),
+            *_TEST_AMD.parametrize(*_BUILD_VARIANTS),
+        ],
+        enable_cache=True,
+        enable_report=True,
+        enable_gh_summary_comment=True,
+        enable_exit_code_result=True,
+    )
+]