diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000..186cd6e
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1,20 @@
+# Build output and VCS data are not needed in the image and are huge
+/target/
+/.git/
+node_modules/
+
+# Local configuration with passwords and runtime data must never get into an image layer
+/config.toml
+/data/
+/assets/data/
+/Maildir/
+
+# Local tooling and scratch files
+/.idea/
+/.vscode/
+/.settings/
+/.project
+/.claude/
+/html/
+/local_history.patch
+/end2end/
diff --git a/Dockerfile b/Dockerfile
index 2b6cf95..30061fb 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -2,9 +2,10 @@ FROM rust:1.86.0-bookworm AS builder
 
 # Install cargo-binstall, which makes it easier to install other
 # cargo extensions like cargo-leptos
-RUN wget https://github.com/cargo-bins/cargo-binstall/releases/latest/download/cargo-binstall-x86_64-unknown-linux-musl.tgz
-RUN tar -xvf cargo-binstall-x86_64-unknown-linux-musl.tgz
-RUN cp cargo-binstall /usr/local/cargo/bin
+# (uname -m gives x86_64 or aarch64, so the image builds on both architectures)
+RUN wget https://github.com/cargo-bins/cargo-binstall/releases/latest/download/cargo-binstall-$(uname -m)-unknown-linux-musl.tgz \
+  && tar -xvf cargo-binstall-$(uname -m)-unknown-linux-musl.tgz \
+  && cp cargo-binstall /usr/local/cargo/bin
 
 # Install required tools
 RUN apt-get update -y \