diff --git a/.envrc b/.envrc
new file mode 100644
index 0000000..3550a30
--- /dev/null
+++ b/.envrc
@@ -0,0 +1 @@
+use flake
diff --git a/.github/workflows/fast.yml b/.github/workflows/fast.yml
deleted file mode 100644
index 636a2c9..0000000
--- a/.github/workflows/fast.yml
+++ /dev/null
@@ -1,25 +0,0 @@
-name: Fast update
-on: 
-  workflow_dispatch:
-  schedule:
-    - cron: '0 * * * *'
-jobs:
-  fast-update:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v2
-        with:
-          persist-credentials: false
-      - name: Set up Python
-        uses: actions/setup-python@v2
-        with:
-          python-version: '3.6' 
-      - name: Build
-        env:
-          GITHUB_TOKEN: ${{ secrets.USER_GITHUB_TOKEN }}
-          SRC_ORG: ${{ secrets.SRC_ORG }}
-          DST_ORG: ${{ secrets.DST_ORG }}
-        run: |
-            pip install pygithub
-            python -u mirror_github_org.py
diff --git a/.github/workflows/full.yml b/.github/workflows/full.yml
index 16a6751..c38f983 100644
--- a/.github/workflows/full.yml
+++ b/.github/workflows/full.yml
@@ -1,25 +1,26 @@
 name: Full update
-on: 
+on:
   workflow_dispatch:
   schedule:
-    - cron: '0 0 * * 0'
+    - cron: '0 */12 * * *'
 jobs:
   full-update:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
         with:
           persist-credentials: false
       - name: Set up Python
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v5
         with:
-          python-version: '3.6' 
-      - name: Build
+          python-version: '3.12'
+          cache: "pip"
+      - name: Install Python dependencies
+        run: pip install -r requirements.txt
+      - name: Run update script
         env:
           GITHUB_TOKEN: ${{ secrets.USER_GITHUB_TOKEN }}
           SRC_ORG: ${{ secrets.SRC_ORG }}
           DST_ORG: ${{ secrets.DST_ORG }}
-        run: |
-            pip install pygithub
-            python -u mirror_github_org.py --full-run
+        run: python mirror_github_org.py
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..92b2793
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+.direnv
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..b76ba81
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,40 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1722987190,
+        "narHash": "sha256-68hmex5efCiM2aZlAAEcQgmFI4ZwWt8a80vOeB/5w3A=",
+        "path": "/nix/store/pi3i4rcxl8iadwxpyyx481ycnyxm856b-source",
+        "rev": "21cc704b5e918c5fbf4f9fff22b4ac2681706d90",
+        "type": "path"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs",
+        "systems": "systems"
+      }
+    },
+    "systems": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "id": "systems",
+        "type": "indirect"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..c0580cb
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,34 @@
+{
+  inputs = {
+    nixpkgs = {};
+    systems.flake = false;
+  };
+
+  outputs = inputs: let
+    inherit (inputs.nixpkgs) lib;
+    defaultSystems = import inputs.systems;
+    argsForSystem = system: {
+      pkgs = inputs.nixpkgs.legacyPackages.${system};
+    };
+    allArgs = lib.genAttrs defaultSystems argsForSystem;
+    eachSystem = fn: lib.genAttrs defaultSystems (system: fn allArgs."${system}");
+  in {
+    formatter = eachSystem ({pkgs, ...}:
+      pkgs.writeShellScriptBin "formatter" ''
+        ${pkgs.alejandra}/bin/alejandra flake.nix
+      '');
+
+    devShells = eachSystem ({pkgs, ...}: {
+      default = pkgs.mkShell {
+        name = "auto_mirror";
+        nativeBuildInputs = [
+          (pkgs.python3.withPackages (p: [
+            p.python-lsp-server
+
+            p.pygithub
+          ]))
+        ];
+      };
+    });
+  };
+}
diff --git a/mirror_github_org.py b/mirror_github_org.py
index d803696..c7742c6 100644
--- a/mirror_github_org.py
+++ b/mirror_github_org.py
@@ -3,6 +3,7 @@
 import time
 import datetime
 import urllib.parse
+from multiprocessing import pool
 
 from github import Github
 from github.GithubException import UnknownObjectException, GithubException
@@ -32,71 +33,75 @@ def check_rate_limiting(rl):
         print("\n")
 
 
-def mirror(token, src_org, dst_org, full_run=False):
-    g = Github(token)
+def mirror(token, src_org, dst_org):
+    g = Github(token, per_page=100)
 
     src_org = g.get_organization(src_org)
     dst_org = g.get_organization(dst_org)
 
-    for src_repo in src_org.get_repos("public", sort="pushed", direction="desc"):
+    print("Building downstream repo index...")
+    dst_repos = {r.name: r for r in dst_org.get_repos("public")}
+
+    def sync_repo(src_repo):
         check_rate_limiting(src_repo)
 
-        dst_repo = None
-        try:
-            dst_repo = dst_org.get_repo(src_repo.name)
-        except UnknownObjectException:
-            pass
+        dst_repo = dst_repos.get(src_repo.name)
+
+        def repo_msg(msg):
+            print(f"{src_repo.name}: {msg}")
 
         if not dst_repo:
-            print("\n\nForking %s..." % src_repo.name, end="")
+            repo_msg("forking...")
             try:
                 response = dst_org.create_fork(src_repo)
             except GithubException as e:
                 if "contains no Git content" in e._GithubException__data["message"]:
                     # Hit an empty repo, which cannot be forked
-                    print("\n * Skipping empty repository", end="")
-                    continue
+                    repo_msg("skipping empty repository")
+                    return
                 else:
                     raise e
 
         else:
-            print("\n\nSyncing %s..." % src_repo.name, end="")
+            repo_msg("syncing...")
 
-            updated = False
-            for src_branch in src_repo.get_branches():
-                check_rate_limiting(src_branch)
+            dst_refs = {r.ref: r for r in dst_repo.get_git_refs()}
+            def copy_ref(src_ref, ref_type):
+                check_rate_limiting(src_ref)
 
-                print("\n - %s " % src_branch.name, end=""),
-                encoded_name = urllib.parse.quote(src_branch.name)
+                encoded_name = urllib.parse.quote(src_ref.name)
+                ref_name = "refs/%s/%s" % (ref_type, encoded_name)
 
-                try:
-                    dst_ref = dst_repo.get_git_ref(ref="heads/%s" % encoded_name)
-                except UnknownObjectException:
-                    dst_ref = None
+                def ref_msg(msg):
+                    print(f"{src_repo.name}({ref_name}): {msg}")
+
+                dst_ref = dst_refs.get(ref_name)
 
                 try:
                     if dst_ref and dst_ref.object:
-                        if src_branch.commit.sha != dst_ref.object.sha:
-                            print("(updated)", end="")
-                            dst_ref.edit(sha=src_branch.commit.sha, force=True)
-                            updated = True
+                        if src_ref.commit.sha != dst_ref.object.sha:
+                            dst_ref.edit(sha=src_ref.commit.sha, force=True)
+                            ref_msg("updated reference")
                     else:
-                        print("(new)", end="")
                         dst_repo.create_git_ref(
-                            ref="refs/heads/%s" % encoded_name, sha=src_branch.commit.sha
+                            ref=ref_name, sha=src_ref.commit.sha
                         )
-                        updated = True
+                        ref_msg("new reference")
 
                 except GithubException as e:
                     if e.status == 422:
-                        print("\n * Github API hit a transient validation error, ignoring for now: ", e, end="")
+                        ref_msg(f"Github API hit a transient validation error, ignoring for now: {e}")
                     else:
                         raise e
 
-            if not full_run and not updated:
-                print("\n\nNo more updates to mirror. Ending run.")
-                sys.exit(0)
+            for src_branch in src_repo.get_branches():
+                copy_ref(src_branch, "heads")
+
+            for src_tag in src_repo.get_tags():
+                copy_ref(src_tag, "tags")
 
+    with pool.ThreadPool(processes=10) as p:
+        p.map(sync_repo, src_org.get_repos("public"))
 
 if __name__ == "__main__":
     p = {}
@@ -106,9 +111,4 @@ def mirror(token, src_org, dst_org, full_run=False):
             print("No %s supplied in env" % param)
             sys.exit(1)
 
-    full_run=False
-    if "--full-run" in sys.argv:
-        print("Doing a full run, will check all repositories and branches - This may take a long time")
-        full_run = True
-
-    mirror(p["GITHUB_TOKEN"], p["SRC_ORG"], p["DST_ORG"], full_run=full_run)
+    mirror(p["GITHUB_TOKEN"], p["SRC_ORG"], p["DST_ORG"])
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..b81016f
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1 @@
+pygithub