diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000..cef6a14
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1,4 @@
+*
+!/Cargo.*
+!/src
+!/crates
diff --git a/.github/workflows/MinedMap.yml b/.github/workflows/MinedMap.yml
index cf75b68..2aef1ec 100644
--- a/.github/workflows/MinedMap.yml
+++ b/.github/workflows/MinedMap.yml
@@ -1,5 +1,14 @@
 name: 'MinedMap'
-on: ['push', 'pull_request', 'workflow_dispatch']
+on:
+  push:
+    branches:
+      - 'main'
+    tags:
+      - 'v*'
+  pull_request:
+    branches:
+      - 'main'
+  workflow_dispatch: {}
 
 env:
   RUSTFLAGS: -Dwarnings
@@ -7,7 +16,7 @@ env:
 
 jobs:
   viewer:
-    runs-on: 'ubuntu-20.04'
+    runs-on: 'ubuntu-latest'
 
     steps:
       - name: 'Checkout'
@@ -25,6 +34,7 @@ jobs:
           pkgdir='build/pkg/MinedMap-${{ steps.tag.outputs.tag }}-viewer'
           mkdir -p "$pkgdir"
           cp -r viewer/* "$pkgdir"/
+          rm "$pkgdir"/Dockerfile
 
       - name: 'Archive'
         uses: 'actions/upload-artifact@v4'
@@ -101,7 +111,7 @@ jobs:
         - os: 'windows-2019'
           target: 'i686-pc-windows-msvc'
           ext: '.exe'
-        - os: 'ubuntu-20.04'
+        - os: 'ubuntu-22.04'
           target: 'x86_64-unknown-linux-gnu'
 
     steps:
@@ -138,3 +148,78 @@ jobs:
         with:
           name: 'MinedMap-${{ steps.tag.outputs.tag }}-${{ matrix.target }}'
           path: 'target/pkg'
+
+  build-container:
+    runs-on: ubuntu-latest
+    needs:
+      - test
+    steps:
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: |
+            ghcr.io/neocturne/minedmap/minedmap
+          tags: |
+            type=raw,value=latest,enable={{is_default_branch}}
+            type=ref,event=branch
+            type=ref,event=branch,suffix=-{{sha}}
+            type=ref,event=pr
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=semver,pattern={{major}}
+
+      - name: Login to GHCR
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - uses: docker/setup-buildx-action@v3
+
+      - name: Build
+        uses: docker/build-push-action@v6
+        with:
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+
+  viewer-container:
+    runs-on: ubuntu-latest
+    needs:
+      - test
+    steps:
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: |
+            ghcr.io/neocturne/minedmap/viewer
+          tags: |
+            type=raw,value=latest,enable={{is_default_branch}}
+            type=ref,event=branch
+            type=ref,event=branch,suffix=-{{sha}}
+            type=ref,event=pr
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=semver,pattern={{major}}
+
+      - name: Login to GHCR
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - uses: docker/setup-buildx-action@v3
+
+      - name: Build
+        uses: docker/build-push-action@v6
+        with:
+          context: "{{defaultContext}}:viewer"
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
diff --git a/CHANGELOG.md b/CHANGELOG.md
index bec566e..e8fd052 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,22 @@
 
 ### Added
 
+- Added experimental watch mode
+
+  Passing `--watch` will cause MinedMap to run continuously instead of exiting
+  after map generation, regenerating tiles whenever they change.
+
+  `--watch-delay` can be used to configure the delay between detecting a change
+  and runing the map generation, also limiting how often the regeneration
+  happens. This defaults to `30s`; significantly smaller values probably don't
+  make sense because Minecraft writes out changes in batches anyways.
+
+  Finally, `--jobs-initial` can be used to configure the number of parallel
+  generation threads for the initial cycle separately from the value used for
+  subsequent cycles after a change is detected (`-j`/`--jobs`). Subsequent
+  cycles usually need to regenerate only a small number of tiles, so setting
+  `--jobs` to a smaller value than `--jobs-initial` may be advantageous.
+
 - Added jemalloc support to fix performace on musl targets
 
   The global allocator can be switched to jemalloc by enabling the `jemalloc`
diff --git a/Cargo.lock b/Cargo.lock
index eeaede2..039e940 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -68,7 +68,7 @@ version = "1.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "79947af37f4177cfead1110013d678905c37501914fba0efea834c3fe9a8d60c"
 dependencies = [
- "windows-sys",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -79,7 +79,7 @@ checksum = "ca3534e77181a9cc07539ad51f2141fe32f6c3ffd4df76db8ad92346b003ae4e"
 dependencies = [
  "anstyle",
  "once_cell",
- "windows-sys",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -321,7 +321,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "33d852cb9b869c2a9b3df2f71a3074817f01e1844f839a144f5fcef059a4eb5d"
 dependencies = [
  "libc",
- "windows-sys",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -345,6 +345,18 @@ dependencies = [
  "simd-adler32",
 ]
 
+[[package]]
+name = "filetime"
+version = "0.2.25"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "35c0522e981e68cbfa8c3f978441a5f34b30b96e146b33cd3359176b50fe8586"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "libredox",
+ "windows-sys 0.59.0",
+]
+
 [[package]]
 name = "flate2"
 version = "1.0.35"
@@ -362,6 +374,15 @@ version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a0d2fde1f7b3d48b8395d5f2de76c18a528bd6a9cdde438df747bfcba3e05d6f"
 
+[[package]]
+name = "fsevent-sys"
+version = "4.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "76ee7a02da4d231650c7cea31349b889be2f45ddb3ef3032d2ec8185f6313fd2"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "futures-core"
 version = "0.3.31"
@@ -454,6 +475,12 @@ version = "0.3.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d231dfb89cfffdbc30e7fc41579ed6066ad03abda9e567ccafae602b97ec5024"
 
+[[package]]
+name = "humantime"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a3a5bfb195931eeb336b2a7b4d761daec841b97f947d34394601737a7bba5e4"
+
 [[package]]
 name = "image"
 version = "0.25.5"
@@ -488,6 +515,26 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "inotify"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f37dccff2791ab604f9babef0ba14fbe0be30bd368dc541e2b08d07c8aa908f3"
+dependencies = [
+ "bitflags 2.8.0",
+ "inotify-sys",
+ "libc",
+]
+
+[[package]]
+name = "inotify-sys"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e05c02b5e89bff3b946cedeca278abc628fe811e604f027c45a8aa3cf793d0eb"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "is_terminal_polyfill"
 version = "1.70.1"
@@ -518,6 +565,26 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "kqueue"
+version = "1.0.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7447f1ca1b7b563588a205fe93dea8df60fd981423a768bc1c0ded35ed147d0c"
+dependencies = [
+ "kqueue-sys",
+ "libc",
+]
+
+[[package]]
+name = "kqueue-sys"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed9625ffda8729b85e45cf04090035ac368927b8cebc34898e7c120f52e4838b"
+dependencies = [
+ "bitflags 1.3.2",
+ "libc",
+]
+
 [[package]]
 name = "lazy_static"
 version = "1.5.0"
@@ -530,6 +597,17 @@ version = "0.2.169"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b5aba8db14291edd000dfcc4d620c7ebfb122c613afb886ca8803fa4e128a20a"
 
+[[package]]
+name = "libredox"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c0ff37bd590ca25063e35af745c343cb7a0271906fb7b37e4813e8f79f00268d"
+dependencies = [
+ "bitflags 2.8.0",
+ "libc",
+ "redox_syscall",
+]
+
 [[package]]
 name = "libz-ng-sys"
 version = "1.1.21"
@@ -588,6 +666,7 @@ dependencies = [
  "fastnbt",
  "futures-util",
  "git-version",
+ "humantime",
  "image",
  "indexmap",
  "lru",
@@ -595,6 +674,7 @@ dependencies = [
  "minedmap-nbt",
  "minedmap-resource",
  "minedmap-types",
+ "notify",
  "num-integer",
  "num_cpus",
  "phf",
@@ -656,6 +736,43 @@ dependencies = [
  "simd-adler32",
 ]
 
+[[package]]
+name = "mio"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2886843bf800fba2e3377cff24abf6379b4c4d5c6681eaf9ea5b0d15090450bd"
+dependencies = [
+ "libc",
+ "log",
+ "wasi",
+ "windows-sys 0.52.0",
+]
+
+[[package]]
+name = "notify"
+version = "8.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2fee8403b3d66ac7b26aee6e40a897d85dc5ce26f44da36b8b73e987cc52e943"
+dependencies = [
+ "bitflags 2.8.0",
+ "filetime",
+ "fsevent-sys",
+ "inotify",
+ "kqueue",
+ "libc",
+ "log",
+ "mio",
+ "notify-types",
+ "walkdir",
+ "windows-sys 0.59.0",
+]
+
+[[package]]
+name = "notify-types"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5e0826a989adedc2a244799e823aece04662b66609d96af8dff7ac6df9a8925d"
+
 [[package]]
 name = "nu-ansi-term"
 version = "0.46.0"
@@ -930,7 +1047,7 @@ dependencies = [
  "errno",
  "libc",
  "linux-raw-sys",
- "windows-sys",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -939,6 +1056,15 @@ version = "1.0.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6ea1a2d0a644769cc99faa24c3ad26b379b786fe7c36fd3c546254801650e6dd"
 
+[[package]]
+name = "same-file"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
+dependencies = [
+ "winapi-util",
+]
+
 [[package]]
 name = "scopeguard"
 version = "1.2.0"
@@ -1052,7 +1178,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5352447f921fda68cf61b4101566c0bdb5104eff6804d0678e5227580ab6a4e9"
 dependencies = [
  "rustix",
- "windows-sys",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -1171,6 +1297,22 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ba73ea9cf16a25df0c8caa16c51acb937d5712a8429db78a3ee29d5dcacd3a65"
 
+[[package]]
+name = "walkdir"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "29790946404f91d9c5d06f9874efddea1dc06c5efe94541a7d6863108e3a5e4b"
+dependencies = [
+ "same-file",
+ "winapi-util",
+]
+
+[[package]]
+name = "wasi"
+version = "0.11.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
+
 [[package]]
 name = "winapi"
 version = "0.3.9"
@@ -1187,12 +1329,30 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
 
+[[package]]
+name = "winapi-util"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cf221c93e13a30d793f7645a0e7762c55d169dbb0a49671918a2319d289b10bb"
+dependencies = [
+ "windows-sys 0.59.0",
+]
+
 [[package]]
 name = "winapi-x86_64-pc-windows-gnu"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
 
+[[package]]
+name = "windows-sys"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
+dependencies = [
+ "windows-targets",
+]
+
 [[package]]
 name = "windows-sys"
 version = "0.59.0"
diff --git a/Cargo.toml b/Cargo.toml
index 998de6c..d213a56 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -44,6 +44,7 @@ enum-map = "2.7.3"
 fastnbt = "2.3.2"
 futures-util = "0.3.28"
 git-version = "0.3.5"
+humantime = "2.1.0"
 image = { version = "0.25.1", default-features = false, features = ["png", "webp"] }
 indexmap = { version = "2.0.0", features = ["serde"] }
 lru = "0.13.0"
@@ -51,6 +52,7 @@ minedmap-default-alloc = { version = "0.1.0", path = "crates/default-alloc", opt
 minedmap-nbt = { version = "0.1.1", path = "crates/nbt", default-features = false }
 minedmap-resource = { version = "0.6.0", path = "crates/resource" }
 minedmap-types = { version = "0.1.4", path = "crates/types" }
+notify = "8.0.0"
 num-integer = "0.1.45"
 num_cpus = "1.16.0"
 phf = { version = "0.11.2", features = ["macros"] }
diff --git a/Dockerfile b/Dockerfile
index fa3627c..e052309 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,14 +1,15 @@
-FROM docker.io/library/rust:alpine AS BUILDER
+FROM docker.io/library/alpine:latest AS builder
 
 WORKDIR /build
-RUN apk update && apk add cmake build-base
+RUN apk add --no-cache build-base cmake cargo
 
-COPY src /build/src
-COPY crates /build/crates
-COPY Cargo.toml Cargo.lock /build
+COPY . .
 RUN cargo build -r 
+RUN strip target/release/minedmap
 
-FROM scratch AS RUNNER
+FROM docker.io/library/alpine:latest
 
-COPY --from=BUILDER /build/target/release/minedmap /minedmap
-ENTRYPOINT [ "/minedmap" ]
+RUN apk add --no-cache libgcc tini
+
+COPY --from=builder /build/target/release/minedmap /bin/minedmap
+ENTRYPOINT [ "/sbin/tini", "--", "/bin/minedmap" ]
diff --git a/src/core/common.rs b/src/core/common.rs
index edefcb3..a81dbf2 100644
--- a/src/core/common.rs
+++ b/src/core/common.rs
@@ -135,10 +135,14 @@ pub enum TileKind {
 pub struct Config {
 	/// Number of threads for parallel processing
 	pub num_threads: usize,
+	/// Number of threads for initial parallel processing
+	pub num_threads_initial: usize,
 	/// Path of input region directory
 	pub region_dir: PathBuf,
 	/// Path of input `level.dat` file
 	pub level_dat_path: PathBuf,
+	/// Path of input `level.dat_old` file
+	pub level_dat_old_path: PathBuf,
 	/// Base path for storage of rendered tile data
 	pub output_dir: PathBuf,
 	/// Path for storage of intermediate processed data files
@@ -167,9 +171,13 @@ impl Config {
 			Some(threads) => threads,
 			None => 1,
 		};
+		let num_threads_initial = args.jobs_initial.unwrap_or(num_threads);
 
 		let region_dir = [&args.input_dir, Path::new("region")].iter().collect();
 		let level_dat_path = [&args.input_dir, Path::new("level.dat")].iter().collect();
+		let level_dat_old_path = [&args.input_dir, Path::new("level.dat_old")]
+			.iter()
+			.collect();
 		let processed_dir: PathBuf = [&args.output_dir, Path::new("processed")].iter().collect();
 		let entities_dir: PathBuf = [&processed_dir, Path::new("entities")].iter().collect();
 		let entities_path_final = [&entities_dir, Path::new("entities.bin")].iter().collect();
@@ -184,8 +192,10 @@ impl Config {
 
 		Ok(Config {
 			num_threads,
+			num_threads_initial,
 			region_dir,
 			level_dat_path,
+			level_dat_old_path,
 			output_dir: args.output_dir.clone(),
 			processed_dir,
 			entities_dir,
diff --git a/src/core/metadata_writer.rs b/src/core/metadata_writer.rs
index 92d8566..eb5f59f 100644
--- a/src/core/metadata_writer.rs
+++ b/src/core/metadata_writer.rs
@@ -124,7 +124,14 @@ impl<'a> MetadataWriter<'a> {
 
 	/// Reads and deserializes the `level.dat` of the Minecraft save data
 	fn read_level_dat(&self) -> Result<de::LevelDat> {
-		crate::nbt::data::from_file(&self.config.level_dat_path).context("Failed to read level.dat")
+		let res = crate::nbt::data::from_file(&self.config.level_dat_path);
+		if res.is_err() {
+			if let Ok(level_dat_old) = crate::nbt::data::from_file(&self.config.level_dat_old_path)
+			{
+				return Ok(level_dat_old);
+			}
+		}
+		res.context("Failed to read level.dat")
 	}
 
 	/// Generates [Spawn] data from a [de::LevelDat]
diff --git a/src/core/mod.rs b/src/core/mod.rs
index 5832379..202d017 100644
--- a/src/core/mod.rs
+++ b/src/core/mod.rs
@@ -10,7 +10,12 @@ mod tile_merger;
 mod tile_mipmapper;
 mod tile_renderer;
 
-use std::path::PathBuf;
+use std::{
+	path::PathBuf,
+	sync::mpsc::{self, Receiver},
+	thread,
+	time::Duration,
+};
 
 use anyhow::{Context, Result};
 use clap::Parser;
@@ -18,9 +23,13 @@ use git_version::git_version;
 
 use common::{Config, ImageFormat};
 use metadata_writer::MetadataWriter;
+use notify::{RecommendedWatcher, RecursiveMode, Watcher as _};
+use rayon::ThreadPool;
 use region_processor::RegionProcessor;
 use tile_mipmapper::TileMipmapper;
 use tile_renderer::TileRenderer;
+use tokio::runtime::Runtime;
+use tracing::{info, warn};
 
 use self::entity_collector::EntityCollector;
 
@@ -44,9 +53,26 @@ pub struct Args {
 	/// use one thread per logical CPU core.
 	#[arg(short, long)]
 	pub jobs: Option<usize>,
+	/// Number of parallel threads to use for initial processing
+	///
+	/// Passing this option only makes sense with --watch. The first run after
+	/// starting MinedMap will use as many parallel jobs as configured using
+	/// --job-initial, while subsequent regenerations of tiles will use the
+	/// the number configured using --jobs.
+	///
+	/// If not given, the value from the --jobs option is used.
+	#[arg(long)]
+	pub jobs_initial: Option<usize>,
 	/// Enable verbose messages
 	#[arg(short, long)]
 	pub verbose: bool,
+	/// Watch for file changes and regenerate tiles automatically instead of
+	/// exiting after generation
+	#[arg(long)]
+	pub watch: bool,
+	/// Minimum delay between map generation cycles in watch mode
+	#[arg(long, value_parser = humantime::parse_duration, default_value = "30s")]
+	pub watch_delay: Duration,
 	/// Format of generated map tiles
 	#[arg(long, value_enum, default_value_t)]
 	pub image_format: ImageFormat,
@@ -74,14 +100,73 @@ pub struct Args {
 	pub output_dir: PathBuf,
 }
 
-/// Configures the Rayon thread pool for parallel processing
-fn setup_threads(num_threads: usize) -> Result<()> {
+/// Configures a Rayon thread pool for parallel processing
+fn setup_threads(num_threads: usize) -> Result<ThreadPool> {
 	rayon::ThreadPoolBuilder::new()
 		.num_threads(num_threads)
-		.build_global()
+		.build()
 		.context("Failed to configure thread pool")
 }
 
+/// Runs all MinedMap generation steps, updating all tiles as needed
+fn generate(config: &Config, rt: &Runtime) -> Result<()> {
+	let regions = RegionProcessor::new(config).run()?;
+	TileRenderer::new(config, rt, &regions).run()?;
+	let tiles = TileMipmapper::new(config, &regions).run()?;
+	EntityCollector::new(config, &regions).run()?;
+	MetadataWriter::new(config, &tiles).run()
+}
+
+/// Creates a file watcher for the
+fn create_watcher(args: &Args) -> Result<(RecommendedWatcher, Receiver<()>)> {
+	let (tx, rx) = mpsc::sync_channel::<()>(1);
+	let mut watcher = notify::recommended_watcher(move |res| {
+		// Ignore errors - we already have a watch trigger queued if try_send() fails
+		let event: notify::Event = match res {
+			Ok(event) => event,
+			Err(err) => {
+				warn!("Watch error: {err}");
+				return;
+			}
+		};
+		let notify::EventKind::Modify(modify_kind) = event.kind else {
+			return;
+		};
+		if !matches!(
+			modify_kind,
+			notify::event::ModifyKind::Data(_)
+				| notify::event::ModifyKind::Name(notify::event::RenameMode::To)
+		) {
+			return;
+		}
+		if !event
+			.paths
+			.iter()
+			.any(|path| path.ends_with("level.dat") || path.extension() == Some("mcu".as_ref()))
+		{
+			return;
+		}
+		let _ = tx.try_send(());
+	})?;
+	watcher.watch(&args.input_dir, RecursiveMode::Recursive)?;
+	Ok((watcher, rx))
+}
+
+/// Watches the data directory for changes, returning when a change has happened
+fn wait_watcher(args: &Args, watch_channel: &Receiver<()>) -> Result<()> {
+	info!("Watching for changes...");
+	let () = watch_channel
+		.recv()
+		.context("Failed to read watch event channel")?;
+	info!("Change detected.");
+
+	thread::sleep(args.watch_delay);
+
+	let _ = watch_channel.try_recv();
+
+	Ok(())
+}
+
 /// MinedMap CLI main function
 pub fn cli() -> Result<()> {
 	let args = Args::parse();
@@ -96,17 +181,26 @@ pub fn cli() -> Result<()> {
 		.with_target(false)
 		.init();
 
-	setup_threads(config.num_threads)?;
+	let mut pool = setup_threads(config.num_threads_initial)?;
 
 	let rt = tokio::runtime::Builder::new_current_thread()
 		.build()
 		.unwrap();
 
-	let regions = RegionProcessor::new(&config).run()?;
-	TileRenderer::new(&config, &rt, &regions).run()?;
-	let tiles = TileMipmapper::new(&config, &regions).run()?;
-	EntityCollector::new(&config, &regions).run()?;
-	MetadataWriter::new(&config, &tiles).run()?;
+	let watch = args.watch.then(|| create_watcher(&args)).transpose()?;
 
-	Ok(())
+	pool.install(|| generate(&config, &rt))?;
+
+	let Some((_watcher, watch_channel)) = watch else {
+		// watch mode disabled
+		return Ok(());
+	};
+
+	if config.num_threads != config.num_threads_initial {
+		pool = setup_threads(config.num_threads)?;
+	}
+	pool.install(move || loop {
+		wait_watcher(&args, &watch_channel)?;
+		generate(&config, &rt)?;
+	})
 }
diff --git a/src/core/tile_renderer.rs b/src/core/tile_renderer.rs
index a972b78..24af234 100644
--- a/src/core/tile_renderer.rs
+++ b/src/core/tile_renderer.rs
@@ -134,7 +134,7 @@ impl<'a> TileRenderer<'a> {
 		/// Hashing the value as a single u32 is more efficient than hashing
 		/// the tuple elements separately.
 		fn biome_key((dx, dz, index): (i8, i8, u16)) -> u32 {
-			(dx as u8 as u32) | (dz as u8 as u32) << 8 | (index as u32) << 16
+			(dx as u8 as u32) | ((dz as u8 as u32) << 8) | ((index as u32) << 16)
 		}
 
 		/// One quadrant of the kernel used to smooth biome edges
diff --git a/src/util.rs b/src/util.rs
index a128ef9..ed07ba5 100644
--- a/src/util.rs
+++ b/src/util.rs
@@ -39,7 +39,9 @@ pub fn to_flat_coord<const AXIS: u8>(
 	chunk: ChunkCoord<AXIS>,
 	block: BlockCoord<AXIS>,
 ) -> i32 {
-	(region as i32) << (BLOCK_BITS + CHUNK_BITS) | ((chunk.0 as i32) << BLOCK_BITS | block.0 as i32)
+	((region as i32) << (BLOCK_BITS + CHUNK_BITS))
+		| ((chunk.0 as i32) << BLOCK_BITS)
+		| (block.0 as i32)
 }
 
 /// Splits a flat (linear) coordinate into region, chunk and block numbers
diff --git a/viewer/.dockerignore b/viewer/.dockerignore
new file mode 100644
index 0000000..3af0ccb
--- /dev/null
+++ b/viewer/.dockerignore
@@ -0,0 +1 @@
+/data
diff --git a/Dockerfile.viewer b/viewer/Dockerfile
similarity index 73%
rename from Dockerfile.viewer
rename to viewer/Dockerfile
index 82d50bb..794bcf5 100644
--- a/Dockerfile.viewer
+++ b/viewer/Dockerfile
@@ -1,3 +1,3 @@
 FROM docker.io/library/nginx:alpine
-COPY viewer /usr/share/nginx/html
+COPY . /usr/share/nginx/html
 # datadir should be mounted to: /usr/share/nginx/html/data