diff --git a/test_runner/buildSrc/src/main/kotlin/Deps.kt b/test_runner/buildSrc/src/main/kotlin/Deps.kt
index 68cd264cb1..fc5223b3d5 100644
--- a/test_runner/buildSrc/src/main/kotlin/Deps.kt
+++ b/test_runner/buildSrc/src/main/kotlin/Deps.kt
@@ -18,10 +18,10 @@ object Versions {
     const val DEX_TEST_PARSER = "2.2.1"
 
     // match to Tools -> Kotlin -> Configure Kotlin Plugin Updates -> Update Channel: Stable
-    const val KOTLIN = "1.3.72"
+    const val KOTLIN = "1.4.0"
 
     // https://github.com/Kotlin/kotlinx.coroutines/releases
-    const val KOTLIN_COROUTINES = "1.3.7"
+    const val KOTLIN_COROUTINES = "1.3.9"
 
     // https://github.com/remkop/picocli/releases
     const val PICOCLI = "4.4.0"
@@ -53,7 +53,7 @@ object Versions {
     const val JSOUP = "1.13.1"
 
     // https://github.com/ktorio/ktor/releases
-    const val KTOR = "1.3.2"
+    const val KTOR = "1.4.0"
 
     // https://github.com/qos-ch/logback/releases
     const val LOGBACK = "1.2.3"
diff --git a/test_runner/src/main/kotlin/ftl/args/yml/errors/ConfigurationErrorMessageBuilder.kt b/test_runner/src/main/kotlin/ftl/args/yml/errors/ConfigurationErrorMessageBuilder.kt
index bae86851d6..c974abfd70 100644
--- a/test_runner/src/main/kotlin/ftl/args/yml/errors/ConfigurationErrorMessageBuilder.kt
+++ b/test_runner/src/main/kotlin/ftl/args/yml/errors/ConfigurationErrorMessageBuilder.kt
@@ -24,13 +24,13 @@ object ConfigurationErrorMessageBuilder {
         try {
             val errorModel = parseMessage(errorMessage)
             val errorMessageBuilder = StringBuilder(messageHeader)
-            errorMessageBuilder.appendln(createReferenceChain(errorModel.referenceChain))
+            errorMessageBuilder.appendLine(createReferenceChain(errorModel.referenceChain))
             if (errorModel.propertyName != "") {
-                errorMessageBuilder.appendln(missingElementMessage.format(errorModel.propertyName))
+                errorMessageBuilder.appendLine(missingElementMessage.format(errorModel.propertyName))
             }
-            errorMessageBuilder.appendln(atMessage.format(errorModel.line, errorModel.column))
+            errorMessageBuilder.appendLine(atMessage.format(errorModel.line, errorModel.column))
             yamlTreeNode?.let {
-                errorMessageBuilder.appendln(errorNodeMessage.format(resolveErrorNode(yamlTreeNode, errorModel)))
+                errorMessageBuilder.appendLine(errorNodeMessage.format(resolveErrorNode(yamlTreeNode, errorModel)))
             }
             errorMessageBuilder.toString().trim()
         } catch (error: Exception) {
@@ -40,9 +40,9 @@ object ConfigurationErrorMessageBuilder {
     operator fun invoke(yamlException: MarkedYAMLException): String {
         val problemMark = yamlException.problemMark
         return StringBuilder(messageHeader + yamlException.problem).apply {
-            appendln()
-            appendln(atMessage.format(problemMark.line, problemMark.column))
-            appendln(errorNodeMessage.format(System.lineSeparator() + problemMark._snippet))
+            appendLine()
+            appendLine(atMessage.format(problemMark.line, problemMark.column))
+            appendLine(errorNodeMessage.format(System.lineSeparator() + problemMark._snippet))
         }.toString().trim()
     }
 
diff --git a/test_runner/src/main/kotlin/ftl/environment/LocalesDescription.kt b/test_runner/src/main/kotlin/ftl/environment/LocalesDescription.kt
index b26c704fbd..dec88999d0 100644
--- a/test_runner/src/main/kotlin/ftl/environment/LocalesDescription.kt
+++ b/test_runner/src/main/kotlin/ftl/environment/LocalesDescription.kt
@@ -13,15 +13,15 @@ private fun Locale.prepareDescription() = """
 """.trimIndent().addRegionIfExist(region).addTagsIfExists(this)
 
 private fun String.addRegionIfExist(region: String?) =
-    if (!region.isNullOrEmpty()) StringBuilder(this).appendln("\nregion: $region").trim().toString()
+    if (!region.isNullOrEmpty()) StringBuilder(this).appendLine("\nregion: $region").trim().toString()
     else this
 
 private fun String.addTagsIfExists(locale: Locale) =
-    if (!locale.tags.isNullOrEmpty()) StringBuilder(this).appendln("\ntags:").appendTagsToList(locale)
+    if (!locale.tags.isNullOrEmpty()) StringBuilder(this).appendLine("\ntags:").appendTagsToList(locale)
     else this
 
 private fun StringBuilder.appendTagsToList(locale: Locale) = apply {
-    locale.tags.filterNotNull().forEach { tag -> appendln("- $tag") }
+    locale.tags.filterNotNull().forEach { tag -> appendLine("- $tag") }
 }.trim().toString()
 
 private fun String?.orErrorMessage(locale: String) = this ?: throw FlankGeneralError("ERROR: '$locale' is not a valid locale")
diff --git a/test_runner/src/main/kotlin/ftl/environment/android/AndroidModelDescription.kt b/test_runner/src/main/kotlin/ftl/environment/android/AndroidModelDescription.kt
index 17dbdfaf4b..fd2ece6d06 100644
--- a/test_runner/src/main/kotlin/ftl/environment/android/AndroidModelDescription.kt
+++ b/test_runner/src/main/kotlin/ftl/environment/android/AndroidModelDescription.kt
@@ -25,15 +25,15 @@ private fun AndroidModel.prepareDescription() = """
     .appendThumbnail(thumbnailUrl).trim()
 
 private fun String.appendList(header: String, items: List<String>?) =
-    if (!items.isNullOrEmpty()) StringBuilder(this).appendln().appendln(header).appendItems(items).toString().trim()
+    if (!items.isNullOrEmpty()) StringBuilder(this).appendLine().appendLine(header).appendItems(items).toString().trim()
     else this
 
 private fun StringBuilder.appendItems(items: List<String>) = apply {
-    items.forEach { appendln("- $it") }
+    items.forEach { appendLine("- $it") }
 }
 
 private fun String.appendThumbnail(thumbnailUrl: String?) =
-    if (!thumbnailUrl.isNullOrBlank()) StringBuilder(this).appendln("\n$THUBNAIL_URL_HEADER $thumbnailUrl").toString()
+    if (!thumbnailUrl.isNullOrBlank()) StringBuilder(this).appendLine("\n$THUBNAIL_URL_HEADER $thumbnailUrl").toString()
     else this
 
 private fun String?.orErrorMessage(modelId: String) = this ?: throw FlankGeneralError("ERROR: '$modelId' is not a valid model")
diff --git a/test_runner/src/main/kotlin/ftl/environment/android/AndroidSoftwareVersionDescription.kt b/test_runner/src/main/kotlin/ftl/environment/android/AndroidSoftwareVersionDescription.kt
index 1b09e4f87d..6317628e62 100644
--- a/test_runner/src/main/kotlin/ftl/environment/android/AndroidSoftwareVersionDescription.kt
+++ b/test_runner/src/main/kotlin/ftl/environment/android/AndroidSoftwareVersionDescription.kt
@@ -17,14 +17,15 @@ private fun AndroidVersion.prepareDescription() = """
       year: ${releaseDate.year}
 """.trimIndent().addDataIfExists(tags).addVersion(versionString).trim()
 
-private fun String.addVersion(versionString: String) = StringBuilder(this).appendln("\nversionString: $versionString").toString()
+private fun String.addVersion(versionString: String) = StringBuilder(this).appendLine("\nversionString: $versionString")
+    .toString()
 
 private fun String.addDataIfExists(data: List<String?>?) =
-    if (!data.isNullOrEmpty()) StringBuilder(this).appendln("\n$TAGS_HEADER:").appendDataToList(data)
+    if (!data.isNullOrEmpty()) StringBuilder(this).appendLine("\n$TAGS_HEADER:").appendDataToList(data)
     else this
 
 private fun StringBuilder.appendDataToList(data: List<String?>) = apply {
-    data.filterNotNull().forEach { item -> appendln("- $item") }
+    data.filterNotNull().forEach { item -> appendLine("- $item") }
 }.toString().trim()
 
 private fun String?.orErrorMessage(versionId: String) = this ?: throw FlankGeneralError("ERROR: '$versionId' is not a valid OS version")
diff --git a/test_runner/src/main/kotlin/ftl/environment/ios/IosModelDescription.kt b/test_runner/src/main/kotlin/ftl/environment/ios/IosModelDescription.kt
index 4ccbcf9257..b0b2f88869 100644
--- a/test_runner/src/main/kotlin/ftl/environment/ios/IosModelDescription.kt
+++ b/test_runner/src/main/kotlin/ftl/environment/ios/IosModelDescription.kt
@@ -11,21 +11,21 @@ private fun IosModel.prepareDescription() = "".appendList(DEVICE_CAPABILITIES_HE
     .appendModelBasicData(this).appendList(SUPPORTED_VERSIONS_HEADER, supportedVersionIds).appendList(TAGS_HEADER, tags).trim()
 
 private fun String.appendList(header: String, items: List<String>?) =
-    if (!items.isNullOrEmpty()) StringBuilder(this).appendln(header).appendItems(items).toString()
+    if (!items.isNullOrEmpty()) StringBuilder(this).appendLine(header).appendItems(items).toString()
     else this
 
 private fun StringBuilder.appendItems(items: List<String>) = apply {
-    items.forEach { appendln("- $it") }
+    items.forEach { appendLine("- $it") }
 }
 
-private fun String.appendModelBasicData(model: IosModel) = StringBuilder(this).appendln(
+private fun String.appendModelBasicData(model: IosModel) = StringBuilder(this).appendLine(
     """
-    formFactor: ${model.formFactor}
-    id: ${model.id}
-    name: ${model.name}
-    screenDensity: ${model.screenDensity}
-    screenX: ${model.screenX}
-    screenY: ${model.screenY}
+formFactor: ${model.formFactor}
+id: ${model.id}
+name: ${model.name}
+screenDensity: ${model.screenDensity}
+screenX: ${model.screenX}
+screenY: ${model.screenY}
 """.trimIndent()
 ).toString()
 
diff --git a/test_runner/src/main/kotlin/ftl/environment/ios/IosSoftwareVersionDescription.kt b/test_runner/src/main/kotlin/ftl/environment/ios/IosSoftwareVersionDescription.kt
index 52886c6c56..507597c54b 100644
--- a/test_runner/src/main/kotlin/ftl/environment/ios/IosSoftwareVersionDescription.kt
+++ b/test_runner/src/main/kotlin/ftl/environment/ios/IosSoftwareVersionDescription.kt
@@ -14,11 +14,11 @@ private fun IosVersion.prepareDescription() = """
 """.trimIndent().addDataIfExists(SUPPORTED_VERSIONS_HEADER, supportedXcodeVersionIds).addDataIfExists(TAGS_HEADER, tags)
 
 private fun String.addDataIfExists(header: String, data: List<String?>?) =
-    if (!data.isNullOrEmpty()) StringBuilder(this).appendln("\n$header:").appendDataToList(data)
+    if (!data.isNullOrEmpty()) StringBuilder(this).appendLine("\n$header:").appendDataToList(data)
     else this
 
 private fun StringBuilder.appendDataToList(data: List<String?>) = apply {
-    data.filterNotNull().forEach { item -> appendln("- $item") }
+    data.filterNotNull().forEach { item -> appendLine("- $item") }
 }.toString().trim()
 
 private fun String?.orErrorMessage(versionId: String) = this ?: throw FlankGeneralError("ERROR: '$versionId' is not a valid OS version")
diff --git a/test_runner/src/main/kotlin/ftl/reports/api/CreateTestExecutionData.kt b/test_runner/src/main/kotlin/ftl/reports/api/CreateTestExecutionData.kt
index 156f854d2d..ce10445902 100644
--- a/test_runner/src/main/kotlin/ftl/reports/api/CreateTestExecutionData.kt
+++ b/test_runner/src/main/kotlin/ftl/reports/api/CreateTestExecutionData.kt
@@ -50,5 +50,5 @@ private suspend fun getAsync(toolResultsStep: ToolResultsStep) = coroutineScope
 // This one is a little bit lower but close as possible. The difference is around ~3 seconds.
 private fun List<TestCase>.getStartTimestamp(): Timestamp = this
     .mapNotNull { it.startTime }
-    .minBy { it.asUnixTimestamp() }
+    .minByOrNull { it.asUnixTimestamp() }
     ?: Timestamp()
diff --git a/test_runner/src/main/kotlin/ftl/reports/outcome/TestOutcome.kt b/test_runner/src/main/kotlin/ftl/reports/outcome/TestOutcome.kt
index d064a16e28..691a467677 100644
--- a/test_runner/src/main/kotlin/ftl/reports/outcome/TestOutcome.kt
+++ b/test_runner/src/main/kotlin/ftl/reports/outcome/TestOutcome.kt
@@ -22,7 +22,7 @@ fun List<Environment>.createMatrixOutcomeSummaryUsingEnvironments(
     testDetails = testDetails ?: "Unknown outcome"
 )
 
-private fun List<Environment>.getOutcomeFromEnvironments(): Outcome? = maxBy {
+private fun List<Environment>.getOutcomeFromEnvironments(): Outcome? = maxByOrNull {
     StepOutcome.order.indexOf(it.environmentResult?.outcome?.summary)
 }?.environmentResult?.outcome
 
@@ -36,6 +36,6 @@ fun List<Step>.createMatrixOutcomeSummaryUsingSteps(
     testDetails = testDetails ?: "Unknown outcome"
 )
 
-private fun List<Step>.getOutcomeFromSteps(): Outcome? = maxBy {
+private fun List<Step>.getOutcomeFromSteps(): Outcome? = maxByOrNull {
     StepOutcome.order.indexOf(it.outcome?.summary)
 }?.outcome
diff --git a/test_runner/src/main/kotlin/ftl/run/common/GetLastGcsPath.kt b/test_runner/src/main/kotlin/ftl/run/common/GetLastGcsPath.kt
index 8ba9a4e1bd..17bd2f8a8e 100644
--- a/test_runner/src/main/kotlin/ftl/run/common/GetLastGcsPath.kt
+++ b/test_runner/src/main/kotlin/ftl/run/common/GetLastGcsPath.kt
@@ -13,4 +13,4 @@ internal fun IArgs.getLastGcsPath(): String? = Paths
 
 private fun Array<File>.getLastModifiedDirectory(): File? = this
     .filter(File::isDirectory)
-    .maxBy(File::lastModified)
+    .maxByOrNull(File::lastModified)
diff --git a/test_runner/src/main/kotlin/ftl/run/platform/common/BeforeRunMessage.kt b/test_runner/src/main/kotlin/ftl/run/platform/common/BeforeRunMessage.kt
index 6b71befb30..353df5a562 100644
--- a/test_runner/src/main/kotlin/ftl/run/platform/common/BeforeRunMessage.kt
+++ b/test_runner/src/main/kotlin/ftl/run/platform/common/BeforeRunMessage.kt
@@ -9,18 +9,16 @@ internal fun beforeRunMessage(args: IArgs, testShardChunks: ShardChunks): String
     val testsCount = testShardChunks.sumBy { it.size }
 
     val result = StringBuilder()
-    result.appendln(
-        "  $testsCount test${s(testsCount)} / $shardCount shard${s(
-            shardCount
-        )}"
+    result.appendLine(
+        "  $testsCount test${s(testsCount)} / $shardCount shard${s(shardCount)}"
     )
 
     if (runCount > 1) {
-        result.appendln("  Running ${runCount}x")
+        result.appendLine("  Running ${runCount}x")
         val runDevices = runCount * shardCount
         val runTests = runCount * testsCount
-        result.appendln("    $runDevices total shard${s(runDevices)}")
-        result.appendln("    $runTests total test${s(runTests)}")
+        result.appendLine("    $runDevices total shard${s(runDevices)}")
+        result.appendLine("    $runTests total test${s(runTests)}")
     }
 
     return result.toString()
diff --git a/test_runner/src/main/kotlin/ftl/util/LogTableBuilder.kt b/test_runner/src/main/kotlin/ftl/util/LogTableBuilder.kt
index 8744708be0..3fa0670a7c 100644
--- a/test_runner/src/main/kotlin/ftl/util/LogTableBuilder.kt
+++ b/test_runner/src/main/kotlin/ftl/util/LogTableBuilder.kt
@@ -11,7 +11,7 @@ data class TableColumn(
     val header: String,
     val data: List<String>,
     val dataColor: List<SystemOutColor> = listOf(),
-    val columnSize: Int = ((data + header).maxBy { it.length }?.length ?: 0) + DEFAULT_COLUMN_PADDING
+    val columnSize: Int = ((data + header).maxByOrNull { it.length }?.length ?: 0) + DEFAULT_COLUMN_PADDING
 )
 
 private data class DataWithSize(
@@ -78,7 +78,7 @@ private fun StringBuilder.startTable(rowSizes: List<Int>) {
         endChar = START_TABLE_END_CHAR,
         rowSizes = rowSizes
     )
-    appendln()
+    appendLine()
 }
 
 private fun StringBuilder.rowSeparator(rowSizes: List<Int>) {
@@ -88,11 +88,11 @@ private fun StringBuilder.rowSeparator(rowSizes: List<Int>) {
         endChar = MIDDLE_TABLE_END_CHAR,
         rowSizes = rowSizes
     )
-    appendln()
+    appendLine()
 }
 
 private fun StringBuilder.appendData(tableColumns: Array<out TableColumn>, rowSizes: List<Int>, tableStyle: TableStyle) {
-    val rowCount = (tableColumns.maxBy { it.data.size } ?: tableColumns.first()).data.size
+    val rowCount = (tableColumns.maxByOrNull { it.data.size } ?: tableColumns.first()).data.size
     (0 until rowCount)
         .map { rowNumber ->
             tableColumns.map {
@@ -133,7 +133,7 @@ private fun StringBuilder.appendDataRow(data: List<DataWithSize>) {
         if (it.centered) append(it.center()) else append(it.leftAligned())
         append(TABLE_VERTICAL_LINE)
     }
-    appendln()
+    appendLine()
 }
 
 private fun DataWithSize.leftAligned() = String.format("%-${columnSize}s", " $data")