diff --git a/README.md b/README.md
index 3356c358bc7..3503236b277 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,7 @@
 [![Continuous Build][ci-image]][ci-url]
 [![Coverage Status][codecov-image]][codecov-url]
 [![Maven Central][maven-image]][maven-url]
+[![Reproducible Builds](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/jvm-repo-rebuild/reproducible-central/master/content/io/opentelemetry/java/badge.json)](https://github.com/jvm-repo-rebuild/reproducible-central/blob/master/content/io/opentelemetry/java/README.md)
 
 ## Project Status
 
diff --git a/dependencyManagement/build.gradle.kts b/dependencyManagement/build.gradle.kts
index 9194798c861..806ed9abaa2 100644
--- a/dependencyManagement/build.gradle.kts
+++ b/dependencyManagement/build.gradle.kts
@@ -67,7 +67,7 @@ val DEPENDENCIES = listOf(
   "io.github.netmikey.logunit:logunit-jul:2.0.0",
   "io.jaegertracing:jaeger-client:1.8.1",
   "io.opentelemetry.contrib:opentelemetry-aws-xray-propagator:1.39.0-alpha",
-  "io.opentelemetry.semconv:opentelemetry-semconv-incubating:1.27.0-alpha",
+  "io.opentelemetry.semconv:opentelemetry-semconv-incubating:1.28.0-alpha",
   "io.opentelemetry.proto:opentelemetry-proto:1.3.2-alpha",
   "io.opentracing:opentracing-api:0.33.0",
   "io.opentracing:opentracing-noop:0.33.0",
diff --git a/sdk-extensions/autoconfigure/src/test/java/io/opentelemetry/sdk/autoconfigure/FileConfigurationTest.java b/sdk-extensions/autoconfigure/src/test/java/io/opentelemetry/sdk/autoconfigure/FileConfigurationTest.java
index e3a9bb3ed10..955e5817693 100644
--- a/sdk-extensions/autoconfigure/src/test/java/io/opentelemetry/sdk/autoconfigure/FileConfigurationTest.java
+++ b/sdk-extensions/autoconfigure/src/test/java/io/opentelemetry/sdk/autoconfigure/FileConfigurationTest.java
@@ -31,7 +31,7 @@ class FileConfigurationTest {
   @Test
   void configFile(@TempDir Path tempDir) throws IOException {
     String yaml =
-        "file_format: \"0.1\"\n"
+        "file_format: \"0.3\"\n"
             + "resource:\n"
             + "  attributes:\n"
             + "    - name: service.name\n"
diff --git a/sdk-extensions/autoconfigure/src/testFullConfig/java/io/opentelemetry/sdk/autoconfigure/FileConfigurationTest.java b/sdk-extensions/autoconfigure/src/testFullConfig/java/io/opentelemetry/sdk/autoconfigure/FileConfigurationTest.java
index 3b3869e5bf6..7eface52c5e 100644
--- a/sdk-extensions/autoconfigure/src/testFullConfig/java/io/opentelemetry/sdk/autoconfigure/FileConfigurationTest.java
+++ b/sdk-extensions/autoconfigure/src/testFullConfig/java/io/opentelemetry/sdk/autoconfigure/FileConfigurationTest.java
@@ -55,7 +55,7 @@ class FileConfigurationTest {
   @BeforeEach
   void setup() throws IOException {
     String yaml =
-        "file_format: \"0.1\"\n"
+        "file_format: \"0.3\"\n"
             + "resource:\n"
             + "  attributes:\n"
             + "    - name: service.name\n"
@@ -160,7 +160,7 @@ void configFile_setResultAsGlobalTrue() {
   @Test
   void configFile_Error(@TempDir Path tempDir) throws IOException {
     String yaml =
-        "file_format: \"0.1\"\n"
+        "file_format: \"0.3\"\n"
             + "resource:\n"
             + "  attributes:\n"
             + "    - name: service.name\n"
diff --git a/sdk-extensions/incubator/build.gradle.kts b/sdk-extensions/incubator/build.gradle.kts
index 59acac261ef..92be979672f 100644
--- a/sdk-extensions/incubator/build.gradle.kts
+++ b/sdk-extensions/incubator/build.gradle.kts
@@ -56,8 +56,11 @@ dependencies {
 // 7. deleteJs2pTmp - delete tmp directory
 // ... proceed with normal sourcesJar, compileJava, etc
 
-val configurationTag = "0.3.0"
-val configurationRef = "refs/tags/v$configurationTag" // Replace with commit SHA to point to experiment with a specific commit
+// TODO (trask) revert after the 0.4.0 release
+//  it was needed after 0.3.0 release because file_format in the examples weren't updated prior to the release tag
+// val configurationTag = "0.3.0"
+// val configurationRef = "refs/tags/v$configurationTag" // Replace with commit SHA to point to experiment with a specific commit
+val configurationRef = "cea3905ce0a542d573968c3c47d413143d473cf4"
 val configurationRepoZip = "https://github.com/open-telemetry/opentelemetry-configuration/archive/$configurationRef.zip"
 val buildDirectory = layout.buildDirectory.asFile.get()
 
diff --git a/sdk-extensions/incubator/src/main/java/io/opentelemetry/sdk/extension/incubator/fileconfig/FileConfiguration.java b/sdk-extensions/incubator/src/main/java/io/opentelemetry/sdk/extension/incubator/fileconfig/FileConfiguration.java
index 76cf9cc1fbe..e4004516b73 100644
--- a/sdk-extensions/incubator/src/main/java/io/opentelemetry/sdk/extension/incubator/fileconfig/FileConfiguration.java
+++ b/sdk-extensions/incubator/src/main/java/io/opentelemetry/sdk/extension/incubator/fileconfig/FileConfiguration.java
@@ -49,7 +49,7 @@ public final class FileConfiguration {
 
   private static final Logger logger = Logger.getLogger(FileConfiguration.class.getName());
   private static final Pattern ENV_VARIABLE_REFERENCE =
-      Pattern.compile("\\$\\{([a-zA-Z_][a-zA-Z0-9_]*)(:-([^\n]*))?\\}");
+      Pattern.compile("\\$\\{([a-zA-Z_][a-zA-Z0-9_]*)(:-([^\n}]*))?}");
   private static final ComponentLoader DEFAULT_COMPONENT_LOADER =
       SpiHelper.serviceComponentLoader(FileConfiguration.class.getClassLoader());
 
diff --git a/sdk-extensions/incubator/src/main/java/io/opentelemetry/sdk/extension/incubator/fileconfig/OpenTelemetryConfigurationFactory.java b/sdk-extensions/incubator/src/main/java/io/opentelemetry/sdk/extension/incubator/fileconfig/OpenTelemetryConfigurationFactory.java
index 0213839ee30..5df6a4766a3 100644
--- a/sdk-extensions/incubator/src/main/java/io/opentelemetry/sdk/extension/incubator/fileconfig/OpenTelemetryConfigurationFactory.java
+++ b/sdk-extensions/incubator/src/main/java/io/opentelemetry/sdk/extension/incubator/fileconfig/OpenTelemetryConfigurationFactory.java
@@ -31,8 +31,8 @@ static OpenTelemetryConfigurationFactory getInstance() {
   public OpenTelemetrySdk create(
       OpenTelemetryConfigurationModel model, SpiHelper spiHelper, List<Closeable> closeables) {
     OpenTelemetrySdkBuilder builder = OpenTelemetrySdk.builder();
-    if (!"0.1".equals(model.getFileFormat())) {
-      throw new ConfigurationException("Unsupported file format. Supported formats include: 0.1");
+    if (!"0.3".equals(model.getFileFormat())) {
+      throw new ConfigurationException("Unsupported file format. Supported formats include: 0.3");
     }
 
     if (Objects.equals(Boolean.TRUE, model.getDisabled())) {
diff --git a/sdk-extensions/incubator/src/test/java/io/opentelemetry/sdk/extension/incubator/fileconfig/FileConfigurationCreateTest.java b/sdk-extensions/incubator/src/test/java/io/opentelemetry/sdk/extension/incubator/fileconfig/FileConfigurationCreateTest.java
index d47ae14eb9a..c1a97a8e265 100644
--- a/sdk-extensions/incubator/src/test/java/io/opentelemetry/sdk/extension/incubator/fileconfig/FileConfigurationCreateTest.java
+++ b/sdk-extensions/incubator/src/test/java/io/opentelemetry/sdk/extension/incubator/fileconfig/FileConfigurationCreateTest.java
@@ -103,7 +103,7 @@ void parseAndCreate_Exception_CleansUpPartials() {
     // exporter with OTLP exporter, following by invalid batch exporter which references invalid
     // exporter "foo".
     String yaml =
-        "file_format: \"0.1\"\n"
+        "file_format: \"0.3\"\n"
             + "logger_provider:\n"
             + "  processors:\n"
             + "    - batch:\n"
diff --git a/sdk-extensions/incubator/src/test/java/io/opentelemetry/sdk/extension/incubator/fileconfig/FileConfigurationParseTest.java b/sdk-extensions/incubator/src/test/java/io/opentelemetry/sdk/extension/incubator/fileconfig/FileConfigurationParseTest.java
index 81aa6f4487e..7de63dcb45c 100644
--- a/sdk-extensions/incubator/src/test/java/io/opentelemetry/sdk/extension/incubator/fileconfig/FileConfigurationParseTest.java
+++ b/sdk-extensions/incubator/src/test/java/io/opentelemetry/sdk/extension/incubator/fileconfig/FileConfigurationParseTest.java
@@ -92,7 +92,7 @@ void parse_BadInputStream() {
   void parse_KitchenSinkExampleFile() throws IOException {
     OpenTelemetryConfigurationModel expected = new OpenTelemetryConfigurationModel();
 
-    expected.withFileFormat("0.1");
+    expected.withFileFormat("0.3");
     expected.withDisabled(false);
 
     // General config
@@ -449,7 +449,7 @@ void parse_KitchenSinkExampleFile() throws IOException {
       OpenTelemetryConfigurationModel config = FileConfiguration.parse(configExampleFile);
 
       // General config
-      assertThat(config.getFileFormat()).isEqualTo("0.1");
+      assertThat(config.getFileFormat()).isEqualTo("0.3");
       assertThat(config.getResource()).isEqualTo(resource);
       assertThat(config.getAttributeLimits()).isEqualTo(attributeLimits);
       assertThat(config.getPropagator()).isEqualTo(propagator);
@@ -485,7 +485,7 @@ void parse_KitchenSinkExampleFile() throws IOException {
   @Test
   void parse_nullValuesParsedToEmptyObjects() {
     String objectPlaceholderString =
-        "file_format: \"0.1\"\n"
+        "file_format: \"0.3\"\n"
             + "tracer_provider:\n"
             + "  processors:\n"
             + "    - batch:\n"
@@ -503,7 +503,7 @@ void parse_nullValuesParsedToEmptyObjects() {
             new ByteArrayInputStream(objectPlaceholderString.getBytes(StandardCharsets.UTF_8)));
 
     String noOjbectPlaceholderString =
-        "file_format: \"0.1\"\n"
+        "file_format: \"0.3\"\n"
             + "tracer_provider:\n"
             + "  processors:\n"
             + "    - batch:\n"
@@ -634,6 +634,9 @@ private static java.util.stream.Stream<Arguments> envVarSubstitutionArgs() {
         // Multiple environment variables referenced
         Arguments.of("key1: ${STR_1}${STR_2}\n", mapOf(entry("key1", "value1value2"))),
         Arguments.of("key1: ${STR_1} ${STR_2}\n", mapOf(entry("key1", "value1 value2"))),
+        Arguments.of(
+            "key1: ${STR_1} ${NOT_SET:-default} ${STR_2}\n",
+            mapOf(entry("key1", "value1 default value2"))),
         // Undefined / empty environment variable
         Arguments.of("key1: ${EMPTY_STR}\n", mapOf(entry("key1", null))),
         Arguments.of("key1: ${STR_3}\n", mapOf(entry("key1", null))),
@@ -672,7 +675,7 @@ private static Map<String, Object> mapOf(Map.Entry<String, ?>... entries) {
   @Test
   void read_WithEnvironmentVariables() {
     String yaml =
-        "file_format: \"0.1\"\n"
+        "file_format: \"0.3\"\n"
             + "tracer_provider:\n"
             + "  processors:\n"
             + "    - batch:\n"
@@ -691,7 +694,7 @@ void read_WithEnvironmentVariables() {
     assertThat(model)
         .isEqualTo(
             new OpenTelemetryConfigurationModel()
-                .withFileFormat("0.1")
+                .withFileFormat("0.3")
                 .withTracerProvider(
                     new TracerProviderModel()
                         .withProcessors(
diff --git a/sdk-extensions/incubator/src/test/java/io/opentelemetry/sdk/extension/incubator/fileconfig/OpenTelemetryConfigurationFactoryTest.java b/sdk-extensions/incubator/src/test/java/io/opentelemetry/sdk/extension/incubator/fileconfig/OpenTelemetryConfigurationFactoryTest.java
index 0284a16bac4..5630ea99767 100644
--- a/sdk-extensions/incubator/src/test/java/io/opentelemetry/sdk/extension/incubator/fileconfig/OpenTelemetryConfigurationFactoryTest.java
+++ b/sdk-extensions/incubator/src/test/java/io/opentelemetry/sdk/extension/incubator/fileconfig/OpenTelemetryConfigurationFactoryTest.java
@@ -83,7 +83,7 @@ void create_InvalidFileFormat() {
                   OpenTelemetryConfigurationFactory.getInstance()
                       .create(testCase, spiHelper, closeables))
           .isInstanceOf(ConfigurationException.class)
-          .hasMessage("Unsupported file format. Supported formats include: 0.1");
+          .hasMessage("Unsupported file format. Supported formats include: 0.3");
       cleanup.addCloseables(closeables);
     }
   }
@@ -97,7 +97,7 @@ void create_Defaults() {
     OpenTelemetrySdk sdk =
         OpenTelemetryConfigurationFactory.getInstance()
             .create(
-                new OpenTelemetryConfigurationModel().withFileFormat("0.1"), spiHelper, closeables);
+                new OpenTelemetryConfigurationModel().withFileFormat("0.3"), spiHelper, closeables);
     cleanup.addCloseable(sdk);
     cleanup.addCloseables(closeables);
 
@@ -114,7 +114,7 @@ void create_Disabled() {
         OpenTelemetryConfigurationFactory.getInstance()
             .create(
                 new OpenTelemetryConfigurationModel()
-                    .withFileFormat("0.1")
+                    .withFileFormat("0.3")
                     .withDisabled(true)
                     // Logger provider configuration should be ignored since SDK is disabled
                     .withLoggerProvider(
@@ -208,7 +208,7 @@ void create_Configured() {
         OpenTelemetryConfigurationFactory.getInstance()
             .create(
                 new OpenTelemetryConfigurationModel()
-                    .withFileFormat("0.1")
+                    .withFileFormat("0.3")
                     .withPropagator(
                         new PropagatorModel()
                             .withComposite(
diff --git a/sdk-extensions/incubator/src/test/java/io/opentelemetry/sdk/extension/incubator/fileconfig/YamlStructuredConfigPropertiesTest.java b/sdk-extensions/incubator/src/test/java/io/opentelemetry/sdk/extension/incubator/fileconfig/YamlStructuredConfigPropertiesTest.java
index 757331934bf..25f9a877c95 100644
--- a/sdk-extensions/incubator/src/test/java/io/opentelemetry/sdk/extension/incubator/fileconfig/YamlStructuredConfigPropertiesTest.java
+++ b/sdk-extensions/incubator/src/test/java/io/opentelemetry/sdk/extension/incubator/fileconfig/YamlStructuredConfigPropertiesTest.java
@@ -22,7 +22,7 @@
 class YamlStructuredConfigPropertiesTest {
 
   private static final String extendedSchema =
-      "file_format: \"0.1\"\n"
+      "file_format: \"0.3\"\n"
           + "disabled: false\n"
           + "\n"
           + "resource:\n"
@@ -69,7 +69,7 @@ void setup() {
   @Test
   void configurationSchema() {
     // Validate can read file configuration schema properties
-    assertThat(structuredConfigProps.getString("file_format")).isEqualTo("0.1");
+    assertThat(structuredConfigProps.getString("file_format")).isEqualTo("0.3");
     StructuredConfigProperties resourceProps = structuredConfigProps.getStructured("resource");
     assertThat(resourceProps).isNotNull();
     List<StructuredConfigProperties> resourceAttributesList =