diff --git a/DESCRIPTION b/DESCRIPTION
index 6b4e427e..b84e052b 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -32,6 +32,7 @@ Imports:
   glue,
   lintr (>= 3.0.0),
   logger,
+  processx,
   purrr,
   renv,
   rstudioapi,
diff --git a/NAMESPACE b/NAMESPACE
index 3378e8db..914f4372 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -3,6 +3,7 @@
 export(app)
 export(build_js)
 export(build_sass)
+export(dev)
 export(diagnostics)
 export(format_js)
 export(format_r)
diff --git a/R/node.R b/R/node.R
index 7f0fbae9..f5569489 100644
--- a/R/node.R
+++ b/R/node.R
@@ -2,36 +2,85 @@ node_path <- function(...) {
   fs::path(".rhino", ...)
 }
 
+npm_command <- function() {
+  Sys.getenv("RHINO_NPM", "npm")
+}
+
+# Run a script defined in `package.json`.
+npm_run <- function(...) {
+  # Use `--silent` to prevent `npm` from echoing the command it runs.
+  # The output of the script itself will still be displayed.
+  npm("--silent", "run", ...)
+}
+
 # Run `npm` or an alternative command specified by `RHINO_NPM`.
 # If needed, copy over Node.js template and install dependencies.
 npm <- function(...) {
-  npm_command <- Sys.getenv("RHINO_NPM", "npm")
-  check_system_dependency(
-    cmd = npm_command,
-    dependency_name = ifelse(npm_command == "npm", "Node.js", npm_command),
-    documentation_url = "https://go.appsilon.com/rhino-system-dependencies"
+  node <- node_check()
+  if (!node$status_ok) {
+    node_missing(abort = TRUE)
+  }
+  node_init()
+  node_run(..., wd = node_path())
+}
+
+node_check <- function() {
+  version <- tryCatch(
+    node_run("--version", stdout = "|")$stdout,
+    error = function(e) NULL
+  )
+  list(
+    status_ok = !is.null(version),
+    diagnostic_info = paste(npm_command(), ifelse(is.null(version), "failed", trimws(version)))
   )
-  node_init(npm_command)
-  node_run(npm_command, ...)
 }
 
-node_init <- function(npm_command) {
+node_missing <- function(info = NULL, abort = FALSE) {
+  docs_url <- "https://go.appsilon.com/rhino-system-dependencies" # nolint object_usage_linter
+  msg <- c(
+    "!" = "Failed to run system command {.code {npm_command()}}.",
+    " " = "Do you have Node.js installed? Read more: {.url {docs_url}}",
+    "i" = info
+  )
+  if (abort) {
+    cli::cli_abort(msg)
+  } else {
+    cli::cli_bullets(msg)
+  }
+}
+
+node_init <- function() {
   if (!fs::dir_exists(node_path())) {
     cli::cli_alert_info("Initializing Node.js directory...")
     copy_template("node", node_path())
   }
   if (!fs::dir_exists(node_path("node_modules"))) {
-    cli::cli_alert_info("Installing Node.js packages with {npm_command}...")
-    node_run(npm_command, "install", "--no-audit", "--no-fund")
+    cli::cli_alert_info("Installing Node.js packages with {.code {npm_command()}}...")
+    node_run("install", "--no-audit", "--no-fund", wd = node_path())
   }
 }
 
 # Run the specified command in Node.js directory (assume it already exists).
-node_run <- function(command, ..., status_ok = 0) {
-  withr::with_dir(node_path(), {
-    status <- system2(command = command, args = c(...))
-  })
-  if (status != status_ok) {
-    cli::cli_abort("System command '{command}' exited with status {status}.")
+node_run <- function(..., stdout = NULL, wd = NULL, background = FALSE) {
+  if (background) {
+    run <- processx::process$new
+  } else {
+    run <- processx::run
   }
+
+  # Workaround: {processx} cannot find `npm` on Windows, but it works with a shell.
+  if (.Platform$OS.type == "windows") {
+    command <- "cmd"
+    args <- rlang::chr("/c", npm_command(), ...)
+  } else {
+    command <- npm_command()
+    args <- rlang::chr(...)
+  }
+
+  run(
+    command = command,
+    args = args,
+    stdout = stdout,
+    wd = wd
+  )
 }
diff --git a/R/rhino.R b/R/rhino.R
index f605a179..4d638bc7 100644
--- a/R/rhino.R
+++ b/R/rhino.R
@@ -48,35 +48,6 @@ copy_rproj <- function() {
   )
 }
 
-system_cmd_version <- function(cmd, throw_error = FALSE) {
-  tryCatch(
-    system2(cmd, "--version", stdout = TRUE, stderr = TRUE),
-    error = function(e) {
-      if (isTRUE(throw_error)) cli::cli_abort(e)
-
-      e$message
-    }
-  )
-}
-
-check_system_dependency <- function(
-  cmd,
-  dependency_name,
-  documentation_url,
-  additional_message = NULL
-) {
-  message <- c(
-    glue::glue("Do you have {dependency_name} installed?"),
-    glue::glue("Check {documentation_url} for details."),
-    additional_message
-  )
-
-  tryCatch(
-    system_cmd_version(cmd, TRUE),
-    error = function(e) cli::cli_abort(message)
-  )
-}
-
 #' Print diagnostics
 #'
 #' Prints information which can be useful for diagnosing issues with Rhino.
@@ -93,7 +64,7 @@ diagnostics <- function() {
   writeLines(c(
     paste(Sys.info()[c("sysname", "release", "version")], collapse = " "),
     R.version.string,
-    paste("rhino:", utils::packageVersion("rhino")),
-    paste("node:", system_cmd_version("node"))
+    paste("rhino", utils::packageVersion("rhino")),
+    node_check()$diagnostic_info
   ))
 }
diff --git a/R/tools.R b/R/tools.R
index 0330f5a0..63dd8113 100644
--- a/R/tools.R
+++ b/R/tools.R
@@ -1,3 +1,58 @@
+#' Development mode
+#'
+#' Run application in development mode with automatic rebuilding and reloading.
+#'
+#' This function will launch the Shiny app in
+#' [development mode](https://shiny.posit.co/r/reference/shiny/latest/devmode.html)
+#' (as if `options(shiny.devmode = TRUE)` was set).
+#' The app will be automatically reloaded whenever the sources change.
+#'
+#' Additionally, Rhino will automatically rebuild JavaScript and Sass in the background.
+#' Please note that this feature requires Node.js.
+#'
+#' @param build_js Boolean. Rebuild JavaScript automatically in the background?
+#' @param build_sass Boolean. Rebuild Sass automatically in the background?
+#' @param ... Additional arguments passed to `shiny::runApp()`.
+#' @return None. This function is called for side effects.
+#'
+#' @export
+dev <- function(build_js = TRUE, build_sass = TRUE, ...) {
+  proc <- dev_build(build_js, build_sass)
+  if (!is.null(proc)) on.exit(proc$kill())
+  shiny::with_devmode(TRUE, shiny::runApp(...))
+}
+
+dev_build <- function(build_js, build_sass) {
+  if (!build_js && !build_sass) return()
+
+  node <- node_check()
+  if (!node$status_ok) {
+    node_missing(node$npm_command, info = "JavaScript and Sass won't be automatically rebuilt.")
+    return()
+  }
+
+  if (build_sass) {
+    config <- read_config()
+    if (config$sass != "node") {
+      build_sass <- FALSE
+      cli::cli_bullets(c(
+        "!" = "Sass won't be automatically rebuilt.",
+        "i" = "Use {.code sass: node} configuration in {.file rhino.yml} to enable it."
+      ))
+    }
+  }
+
+  # Is there is anything to do? Check again - building Sass might have been disabled.
+  if (!build_js && !build_sass) return()
+
+  npm_run(
+    "concurrently", "--",
+    if (build_js) "npm:build-js -- --watch",
+    if (build_sass) "npm:build-sass -- --watch",
+    background = TRUE
+  )
+}
+
 #' Run R unit tests
 #'
 #' Uses the `{testhat}` package to run all unit tests in `tests/testthat` directory.
@@ -234,9 +289,9 @@ format_r <- function(paths, exclude_files = NULL) {
 #' @export
 build_js <- function(watch = FALSE) {
   if (watch) {
-    npm("run", "build-js", "--", "--watch", status_ok = 2)
+    npm_run("build-js", "--", "--watch")
   } else {
-    npm("run", "build-js")
+    npm_run("build-js")
   }
 }
 
@@ -273,9 +328,9 @@ build_js <- function(watch = FALSE) {
 # nolint end
 lint_js <- function(fix = FALSE) {
   if (fix) {
-    npm("run", "lint-js", "--", "--fix")
+    npm_run("lint-js", "--", "--fix")
   } else {
-    npm("run", "lint-js")
+    npm_run("lint-js")
   }
 }
 
@@ -296,9 +351,9 @@ lint_js <- function(fix = FALSE) {
 #' @export
 format_js <- function(fix = TRUE) {
   if (fix) {
-    npm("run", "format-js", "--", "--write")
+    npm_run("format-js", "--", "--write")
   } else {
-    npm("run", "format-js", "--", "--check")
+    npm_run("format-js", "--", "--check")
   }
 }
 
@@ -356,9 +411,9 @@ build_sass <- function(watch = FALSE) {
 
 build_sass_node <- function(watch = FALSE) {
   if (watch) {
-    npm("run", "build-sass", "--", "--watch", status_ok = 2)
+    npm_run("build-sass", "--", "--watch")
   } else {
-    npm("run", "build-sass")
+    npm_run("build-sass")
   }
 }
 
@@ -389,9 +444,9 @@ build_sass_r <- function() {
 #' @export
 lint_sass <- function(fix = FALSE) {
   if (fix) {
-    npm("run", "lint-sass", "--", "--fix")
+    npm_run("lint-sass", "--", "--fix")
   } else {
-    npm("run", "lint-sass")
+    npm_run("lint-sass")
   }
 }
 
@@ -412,9 +467,9 @@ lint_sass <- function(fix = FALSE) {
 #' @export
 format_sass <- function(fix = TRUE) {
   if (fix) {
-    npm("run", "format-sass", "--", "--write")
+    npm_run("format-sass", "--", "--write")
   } else {
-    npm("run", "format-sass", "--", "--check")
+    npm_run("format-sass", "--", "--check")
   }
 }
 
@@ -445,8 +500,8 @@ format_sass <- function(fix = TRUE) {
 #' @export
 test_e2e <- function(interactive = FALSE) {
   if (interactive) {
-    npm("run", "test-e2e-interactive")
+    npm_run("test-e2e-interactive")
   } else {
-    npm("run", "test-e2e")
+    npm_run("test-e2e")
   }
 }
diff --git a/inst/templates/node/package-lock.json b/inst/templates/node/package-lock.json
index 76b9d655..57ef5b7b 100644
--- a/inst/templates/node/package-lock.json
+++ b/inst/templates/node/package-lock.json
@@ -11,6 +11,7 @@
         "@babel/preset-env": "^7.23.7",
         "@babel/preset-react": "^7.23.3",
         "babel-loader": "^9.1.3",
+        "concurrently": "^8.2.2",
         "cypress": "^13.6.2",
         "eslint": "^8.56.0",
         "eslint-config-airbnb": "^19.0.4",
@@ -3555,6 +3556,21 @@
         "node": ">=8"
       }
     },
+    "node_modules/cliui": {
+      "version": "8.0.1",
+      "resolved": "https://registry.npmjs.org/cliui/-/cliui-8.0.1.tgz",
+      "integrity": "sha512-BSeNnyus75C4//NQ9gQt1/csTXyo/8Sb+afLAkzAptFuMsod9HFokGNudZpi/oQV73hnVK+sR+5PVRMd+Dr7YQ==",
+      "dev": true,
+      "license": "ISC",
+      "dependencies": {
+        "string-width": "^4.2.0",
+        "strip-ansi": "^6.0.1",
+        "wrap-ansi": "^7.0.0"
+      },
+      "engines": {
+        "node": ">=12"
+      }
+    },
     "node_modules/clone-deep": {
       "version": "4.0.1",
       "dev": true,
@@ -3639,6 +3655,34 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/concurrently": {
+      "version": "8.2.2",
+      "resolved": "https://registry.npmjs.org/concurrently/-/concurrently-8.2.2.tgz",
+      "integrity": "sha512-1dP4gpXFhei8IOtlXRE/T/4H88ElHgTiUzh71YUmtjTEHMSRS2Z/fgOxHSxxusGHogsRfxNq1vyAwxSC+EVyDg==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "chalk": "^4.1.2",
+        "date-fns": "^2.30.0",
+        "lodash": "^4.17.21",
+        "rxjs": "^7.8.1",
+        "shell-quote": "^1.8.1",
+        "spawn-command": "0.0.2",
+        "supports-color": "^8.1.1",
+        "tree-kill": "^1.2.2",
+        "yargs": "^17.7.2"
+      },
+      "bin": {
+        "conc": "dist/bin/concurrently.js",
+        "concurrently": "dist/bin/concurrently.js"
+      },
+      "engines": {
+        "node": "^14.13.0 || >=16.0.0"
+      },
+      "funding": {
+        "url": "https://github.com/open-cli-tools/concurrently?sponsor=1"
+      }
+    },
     "node_modules/confusing-browser-globals": {
       "version": "1.0.11",
       "resolved": "https://registry.npmjs.org/confusing-browser-globals/-/confusing-browser-globals-1.0.11.tgz",
@@ -3842,6 +3886,23 @@
         "node": ">=0.10"
       }
     },
+    "node_modules/date-fns": {
+      "version": "2.30.0",
+      "resolved": "https://registry.npmjs.org/date-fns/-/date-fns-2.30.0.tgz",
+      "integrity": "sha512-fnULvOpxnC5/Vg3NCiWelDsLiUc9bRwAPs/+LfTLNvetFCtCTN+yQz15C/fs4AwX1R9K5GLtLfn8QW+dWisaAw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@babel/runtime": "^7.21.0"
+      },
+      "engines": {
+        "node": ">=0.11"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/date-fns"
+      }
+    },
     "node_modules/dayjs": {
       "version": "1.10.7",
       "dev": true,
@@ -5283,6 +5344,16 @@
         "node": ">=6.9.0"
       }
     },
+    "node_modules/get-caller-file": {
+      "version": "2.0.5",
+      "resolved": "https://registry.npmjs.org/get-caller-file/-/get-caller-file-2.0.5.tgz",
+      "integrity": "sha512-DyFP3BM/3YHTQOCUL/w0OZHR0lpKeGrxotcHWcqNEdnltqFwXVfhEBQ94eIo34AfQpo0rGki4cyIiftY06h2Fg==",
+      "dev": true,
+      "license": "ISC",
+      "engines": {
+        "node": "6.* || 8.* || >= 10.*"
+      }
+    },
     "node_modules/get-intrinsic": {
       "version": "1.2.2",
       "resolved": "https://registry.npmjs.org/get-intrinsic/-/get-intrinsic-1.2.2.tgz",
@@ -7578,6 +7649,16 @@
         "throttleit": "^1.0.0"
       }
     },
+    "node_modules/require-directory": {
+      "version": "2.1.1",
+      "resolved": "https://registry.npmjs.org/require-directory/-/require-directory-2.1.1.tgz",
+      "integrity": "sha512-fGxEI7+wsG9xrvdjsrlmL22OMTTiHRwAMroiEeMgq8gzoLC/PQr7RsRDSTLUg/bZAZtF+TVIkHc6/4RIKrui+Q==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=0.10.0"
+      }
+    },
     "node_modules/require-from-string": {
       "version": "2.0.2",
       "dev": true,
@@ -7868,6 +7949,16 @@
         "node": ">=8"
       }
     },
+    "node_modules/shell-quote": {
+      "version": "1.8.1",
+      "resolved": "https://registry.npmjs.org/shell-quote/-/shell-quote-1.8.1.tgz",
+      "integrity": "sha512-6j1W9l1iAs/4xYBI1SYOVZyFcCis9b4KCLQ8fgAGG07QvzaRLVVRQvAy85yNmmZSjYjg4MWh4gNvlPujU/5LpA==",
+      "dev": true,
+      "license": "MIT",
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
     "node_modules/side-channel": {
       "version": "1.0.4",
       "dev": true,
@@ -7937,6 +8028,12 @@
         "source-map": "^0.6.0"
       }
     },
+    "node_modules/spawn-command": {
+      "version": "0.0.2",
+      "resolved": "https://registry.npmjs.org/spawn-command/-/spawn-command-0.0.2.tgz",
+      "integrity": "sha512-zC8zGoGkmc8J9ndvml8Xksr1Amk9qBujgbF0JAIWO7kXr43w0h/0GJNM/Vustixu+YE8N/MTrQ7N31FvHUACxQ==",
+      "dev": true
+    },
     "node_modules/spdx-correct": {
       "version": "3.1.1",
       "dev": true,
@@ -8566,6 +8663,16 @@
         "node": ">= 4.0.0"
       }
     },
+    "node_modules/tree-kill": {
+      "version": "1.2.2",
+      "resolved": "https://registry.npmjs.org/tree-kill/-/tree-kill-1.2.2.tgz",
+      "integrity": "sha512-L0Orpi8qGpRG//Nd+H90vFB+3iHnue1zSSGmNOOCh1GLJ7rUKVwV2HvijphGQS2UmhUZewS9VgvxYIdgr+fG1A==",
+      "dev": true,
+      "license": "MIT",
+      "bin": {
+        "tree-kill": "cli.js"
+      }
+    },
     "node_modules/trim-newlines": {
       "version": "3.0.1",
       "dev": true,
@@ -9142,6 +9249,16 @@
         "node": "^12.13.0 || ^14.15.0 || >=16.0.0"
       }
     },
+    "node_modules/y18n": {
+      "version": "5.0.8",
+      "resolved": "https://registry.npmjs.org/y18n/-/y18n-5.0.8.tgz",
+      "integrity": "sha512-0pfFzegeDWJHJIAmTLRP2DwHjdF5s7jo9tuztdQxAhINCdvS+3nGINqPd00AphqJR/0LhANUS6/+7SCb98YOfA==",
+      "dev": true,
+      "license": "ISC",
+      "engines": {
+        "node": ">=10"
+      }
+    },
     "node_modules/yallist": {
       "version": "4.0.0",
       "dev": true,
@@ -9156,6 +9273,25 @@
         "node": ">= 6"
       }
     },
+    "node_modules/yargs": {
+      "version": "17.7.2",
+      "resolved": "https://registry.npmjs.org/yargs/-/yargs-17.7.2.tgz",
+      "integrity": "sha512-7dSzzRQ++CKnNI/krKnYRV7JKKPUXMEh61soaHKg9mrWEhzFWhFnxPxGl+69cD1Ou63C13NUPCnmIcrvqCuM6w==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "cliui": "^8.0.1",
+        "escalade": "^3.1.1",
+        "get-caller-file": "^2.0.5",
+        "require-directory": "^2.1.1",
+        "string-width": "^4.2.3",
+        "y18n": "^5.0.5",
+        "yargs-parser": "^21.1.1"
+      },
+      "engines": {
+        "node": ">=12"
+      }
+    },
     "node_modules/yargs-parser": {
       "version": "20.2.9",
       "dev": true,
@@ -9164,6 +9300,16 @@
         "node": ">=10"
       }
     },
+    "node_modules/yargs/node_modules/yargs-parser": {
+      "version": "21.1.1",
+      "resolved": "https://registry.npmjs.org/yargs-parser/-/yargs-parser-21.1.1.tgz",
+      "integrity": "sha512-tVpsJW7DdjecAiFpbIB1e3qxIQsE6NoPc5/eTdrbbIC4h0LVsWhnoa3g+m2HclBIujHzsxZ4VJVA+GUuc2/LBw==",
+      "dev": true,
+      "license": "ISC",
+      "engines": {
+        "node": ">=12"
+      }
+    },
     "node_modules/yauzl": {
       "version": "2.10.0",
       "dev": true,
@@ -11691,6 +11837,17 @@
         }
       }
     },
+    "cliui": {
+      "version": "8.0.1",
+      "resolved": "https://registry.npmjs.org/cliui/-/cliui-8.0.1.tgz",
+      "integrity": "sha512-BSeNnyus75C4//NQ9gQt1/csTXyo/8Sb+afLAkzAptFuMsod9HFokGNudZpi/oQV73hnVK+sR+5PVRMd+Dr7YQ==",
+      "dev": true,
+      "requires": {
+        "string-width": "^4.2.0",
+        "strip-ansi": "^6.0.1",
+        "wrap-ansi": "^7.0.0"
+      }
+    },
     "clone-deep": {
       "version": "4.0.1",
       "dev": true,
@@ -11751,6 +11908,23 @@
       "version": "0.0.1",
       "dev": true
     },
+    "concurrently": {
+      "version": "8.2.2",
+      "resolved": "https://registry.npmjs.org/concurrently/-/concurrently-8.2.2.tgz",
+      "integrity": "sha512-1dP4gpXFhei8IOtlXRE/T/4H88ElHgTiUzh71YUmtjTEHMSRS2Z/fgOxHSxxusGHogsRfxNq1vyAwxSC+EVyDg==",
+      "dev": true,
+      "requires": {
+        "chalk": "^4.1.2",
+        "date-fns": "^2.30.0",
+        "lodash": "^4.17.21",
+        "rxjs": "^7.8.1",
+        "shell-quote": "^1.8.1",
+        "spawn-command": "0.0.2",
+        "supports-color": "^8.1.1",
+        "tree-kill": "^1.2.2",
+        "yargs": "^17.7.2"
+      }
+    },
     "confusing-browser-globals": {
       "version": "1.0.11",
       "resolved": "https://registry.npmjs.org/confusing-browser-globals/-/confusing-browser-globals-1.0.11.tgz",
@@ -11909,6 +12083,15 @@
         "assert-plus": "^1.0.0"
       }
     },
+    "date-fns": {
+      "version": "2.30.0",
+      "resolved": "https://registry.npmjs.org/date-fns/-/date-fns-2.30.0.tgz",
+      "integrity": "sha512-fnULvOpxnC5/Vg3NCiWelDsLiUc9bRwAPs/+LfTLNvetFCtCTN+yQz15C/fs4AwX1R9K5GLtLfn8QW+dWisaAw==",
+      "dev": true,
+      "requires": {
+        "@babel/runtime": "^7.21.0"
+      }
+    },
     "dayjs": {
       "version": "1.10.7",
       "dev": true
@@ -12945,6 +13128,12 @@
       "version": "1.0.0-beta.2",
       "dev": true
     },
+    "get-caller-file": {
+      "version": "2.0.5",
+      "resolved": "https://registry.npmjs.org/get-caller-file/-/get-caller-file-2.0.5.tgz",
+      "integrity": "sha512-DyFP3BM/3YHTQOCUL/w0OZHR0lpKeGrxotcHWcqNEdnltqFwXVfhEBQ94eIo34AfQpo0rGki4cyIiftY06h2Fg==",
+      "dev": true
+    },
     "get-intrinsic": {
       "version": "1.2.2",
       "resolved": "https://registry.npmjs.org/get-intrinsic/-/get-intrinsic-1.2.2.tgz",
@@ -14454,6 +14643,12 @@
         "throttleit": "^1.0.0"
       }
     },
+    "require-directory": {
+      "version": "2.1.1",
+      "resolved": "https://registry.npmjs.org/require-directory/-/require-directory-2.1.1.tgz",
+      "integrity": "sha512-fGxEI7+wsG9xrvdjsrlmL22OMTTiHRwAMroiEeMgq8gzoLC/PQr7RsRDSTLUg/bZAZtF+TVIkHc6/4RIKrui+Q==",
+      "dev": true
+    },
     "require-from-string": {
       "version": "2.0.2",
       "dev": true
@@ -14636,6 +14831,12 @@
       "version": "3.0.0",
       "dev": true
     },
+    "shell-quote": {
+      "version": "1.8.1",
+      "resolved": "https://registry.npmjs.org/shell-quote/-/shell-quote-1.8.1.tgz",
+      "integrity": "sha512-6j1W9l1iAs/4xYBI1SYOVZyFcCis9b4KCLQ8fgAGG07QvzaRLVVRQvAy85yNmmZSjYjg4MWh4gNvlPujU/5LpA==",
+      "dev": true
+    },
     "side-channel": {
       "version": "1.0.4",
       "dev": true,
@@ -14682,6 +14883,12 @@
         "source-map": "^0.6.0"
       }
     },
+    "spawn-command": {
+      "version": "0.0.2",
+      "resolved": "https://registry.npmjs.org/spawn-command/-/spawn-command-0.0.2.tgz",
+      "integrity": "sha512-zC8zGoGkmc8J9ndvml8Xksr1Amk9qBujgbF0JAIWO7kXr43w0h/0GJNM/Vustixu+YE8N/MTrQ7N31FvHUACxQ==",
+      "dev": true
+    },
     "spdx-correct": {
       "version": "3.1.1",
       "dev": true,
@@ -15131,6 +15338,12 @@
         }
       }
     },
+    "tree-kill": {
+      "version": "1.2.2",
+      "resolved": "https://registry.npmjs.org/tree-kill/-/tree-kill-1.2.2.tgz",
+      "integrity": "sha512-L0Orpi8qGpRG//Nd+H90vFB+3iHnue1zSSGmNOOCh1GLJ7rUKVwV2HvijphGQS2UmhUZewS9VgvxYIdgr+fG1A==",
+      "dev": true
+    },
     "trim-newlines": {
       "version": "3.0.1",
       "dev": true
@@ -15525,6 +15738,12 @@
         "signal-exit": "^3.0.7"
       }
     },
+    "y18n": {
+      "version": "5.0.8",
+      "resolved": "https://registry.npmjs.org/y18n/-/y18n-5.0.8.tgz",
+      "integrity": "sha512-0pfFzegeDWJHJIAmTLRP2DwHjdF5s7jo9tuztdQxAhINCdvS+3nGINqPd00AphqJR/0LhANUS6/+7SCb98YOfA==",
+      "dev": true
+    },
     "yallist": {
       "version": "4.0.0",
       "dev": true
@@ -15535,6 +15754,29 @@
       "integrity": "sha512-r3vXyErRCYJ7wg28yvBY5VSoAF8ZvlcW9/BwUzEtUsjvX/DKs24dIkuwjtuprwJJHsbyUbLApepYTR1BN4uHrg==",
       "dev": true
     },
+    "yargs": {
+      "version": "17.7.2",
+      "resolved": "https://registry.npmjs.org/yargs/-/yargs-17.7.2.tgz",
+      "integrity": "sha512-7dSzzRQ++CKnNI/krKnYRV7JKKPUXMEh61soaHKg9mrWEhzFWhFnxPxGl+69cD1Ou63C13NUPCnmIcrvqCuM6w==",
+      "dev": true,
+      "requires": {
+        "cliui": "^8.0.1",
+        "escalade": "^3.1.1",
+        "get-caller-file": "^2.0.5",
+        "require-directory": "^2.1.1",
+        "string-width": "^4.2.3",
+        "y18n": "^5.0.5",
+        "yargs-parser": "^21.1.1"
+      },
+      "dependencies": {
+        "yargs-parser": {
+          "version": "21.1.1",
+          "resolved": "https://registry.npmjs.org/yargs-parser/-/yargs-parser-21.1.1.tgz",
+          "integrity": "sha512-tVpsJW7DdjecAiFpbIB1e3qxIQsE6NoPc5/eTdrbbIC4h0LVsWhnoa3g+m2HclBIujHzsxZ4VJVA+GUuc2/LBw==",
+          "dev": true
+        }
+      }
+    },
     "yargs-parser": {
       "version": "20.2.9",
       "dev": true
diff --git a/inst/templates/node/package.json b/inst/templates/node/package.json
index 8d62ba4d..66bb9e13 100644
--- a/inst/templates/node/package.json
+++ b/inst/templates/node/package.json
@@ -1,8 +1,9 @@
 {
   "private": true,
   "scripts": {
+    "concurrently": "concurrently",
     "build-js": "webpack",
-    "build-sass": "sass --no-source-map --style=compressed ../app/styles/main.scss:../app/static/css/app.min.css",
+    "build-sass": "sass --no-source-map --style=compressed --color ../app/styles/main.scss:../app/static/css/app.min.css",
     "lint-js": "eslint --config .eslintrc.json ../app/js",
     "lint-sass": "stylelint ../app/styles",
     "format-js": "prettier --config prettier.config.mjs --ignore-path none ../app/js/**/*.js",
@@ -19,6 +20,7 @@
     "@babel/preset-env": "^7.23.7",
     "@babel/preset-react": "^7.23.3",
     "babel-loader": "^9.1.3",
+    "concurrently": "^8.2.2",
     "cypress": "^13.6.2",
     "eslint": "^8.56.0",
     "eslint-config-airbnb": "^19.0.4",
diff --git a/man/dev.Rd b/man/dev.Rd
new file mode 100644
index 00000000..dafb8894
--- /dev/null
+++ b/man/dev.Rd
@@ -0,0 +1,30 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/tools.R
+\name{dev}
+\alias{dev}
+\title{Development mode}
+\usage{
+dev(build_js = TRUE, build_sass = TRUE, ...)
+}
+\arguments{
+\item{build_js}{Boolean. Rebuild JavaScript automatically in the background?}
+
+\item{build_sass}{Boolean. Rebuild Sass automatically in the background?}
+
+\item{...}{Additional arguments passed to \code{shiny::runApp()}.}
+}
+\value{
+None. This function is called for side effects.
+}
+\description{
+Run application in development mode with automatic rebuilding and reloading.
+}
+\details{
+This function will launch the Shiny app in
+\href{https://shiny.posit.co/r/reference/shiny/latest/devmode.html}{development mode}
+(as if \code{options(shiny.devmode = TRUE)} was set).
+The app will be automatically reloaded whenever the sources change.
+
+Additionally, Rhino will automatically rebuild JavaScript and Sass in the background.
+Please note that this feature requires Node.js.
+}
diff --git a/pkgdown/_pkgdown.yml b/pkgdown/_pkgdown.yml
index e1cc4812..48a8c78c 100644
--- a/pkgdown/_pkgdown.yml
+++ b/pkgdown/_pkgdown.yml
@@ -141,6 +141,7 @@ reference:
 
 - title: R development
   contents:
+  - dev
   - dependencies
   - log
   - format_r