diff --git a/backend/AGENTS.md b/backend/AGENTS.md
index 1b14ec2..a3f70c4 100644
--- a/backend/AGENTS.md
+++ b/backend/AGENTS.md
@@ -43,6 +43,7 @@ backend/
 ## Workflow
 
 - Use `just backend::<recipe>` from the repository root. Before completing backend changes, run `format`, `clippy`, `test` and `build`.
+- Development builds carry line tables only; use the `debugging` Cargo profile when you need full debug symbols.
 - Follow [`dev/AGENTS.md`](../dev/AGENTS.md) for the development stack, the workspace environment and `DOTCORE_BACKEND_RUN_MODE`. Composition owns the `DOTCORE_*` variables the backend reads; `dev/workspace-environment.mjs` derives them.
 - Every crate is published to crates.io, and each one must build from its own package: no build input outside its folder. `proto/dotcore` is a link to the repository's contracts for that reason; keep it a link. A new workspace crate:
   - inherits the shared package fields (`version`, `license`, `repository`, `homepage`, `readme`) with `.workspace = true`, and gets a `[workspace.dependencies]` entry with its version
diff --git a/backend/Cargo.toml b/backend/Cargo.toml
index ee31dee..0a7839c 100644
--- a/backend/Cargo.toml
+++ b/backend/Cargo.toml
@@ -57,3 +57,11 @@ tracing-appender = "0.2.5"
 tracing-subscriber = "0.3.23"
 url = "2.5.8"
 x509-parser = "0.18.0"
+
+# Line tables only to keep target dirs small; `debugging` has full symbols.
+[profile.dev]
+debug = "line-tables-only"
+
+[profile.debugging]
+inherits = "dev"
+debug = true
diff --git a/backend/Justfile b/backend/Justfile
index 144c23d..bbfaa96 100644
--- a/backend/Justfile
+++ b/backend/Justfile
@@ -133,9 +133,9 @@ gate-hardware-coverage:
   fi
   echo "hardware coverage gate: OK ($(wc -l < "$dir/hw_ignored" | tr -d ' ') hardware tests, $(wc -l < "$dir/allow" | tr -d ' ') marked non-hardware ignored tests)"
 
-# Build all backend workspace packages with locked dependencies.
-build:
-  cargo build --locked --workspace
+# Build all backend workspace packages with locked dependencies; extra arguments go to Cargo, such as a profile.
+build *args:
+  cargo build --locked --workspace "$@"
 
 # Remove Rust build output.
 clean: