diff --git a/Sources/Sentry/SentryProfiler.mm b/Sources/Sentry/SentryProfiler.mm
index 10abab1dd1d..b86702ee409 100644
--- a/Sources/Sentry/SentryProfiler.mm
+++ b/Sources/Sentry/SentryProfiler.mm
@@ -1,8 +1,10 @@
 #import "SentryProfiler.h"
 
 #if SENTRY_TARGET_PROFILING_SUPPORTED
+#    import "NSDate+SentryExtras.h"
 #    import "SentryBacktrace.hpp"
 #    import "SentryClient+Private.h"
+#    import "SentryCurrentDate.h"
 #    import "SentryDebugImageProvider.h"
 #    import "SentryDebugMeta.h"
 #    import "SentryDefines.h"
@@ -356,9 +358,9 @@ - (void)start
         const auto queueMetadata = [NSMutableDictionary<NSString *, NSDictionary *> dictionary];
         sampledProfile[@"thread_metadata"] = threadMetadata;
         sampledProfile[@"queue_metadata"] = queueMetadata;
-        _profile[@"sampled_profile"] = sampledProfile;
+        _profile[@"profile"] = sampledProfile;
         _startTimestamp = getAbsoluteTime();
-        _startDate = [NSDate date];
+        _startDate = [SentryCurrentDate date];
 
         SENTRY_LOG_DEBUG(@"Starting profiler %@ at system time %llu.", self, _startTimestamp);
 
@@ -378,9 +380,6 @@ - (void)start
                 NSMutableDictionary<NSString *, id> *metadata = threadMetadata[threadID];
                 if (metadata == nil) {
                     metadata = [NSMutableDictionary<NSString *, id> dictionary];
-                    if (backtrace.threadMetadata.threadID == mainThreadID) {
-                        metadata[@"is_main_thread"] = @YES;
-                    }
                     threadMetadata[threadID] = metadata;
                 }
                 if (!backtrace.threadMetadata.name.empty() && metadata[@"name"] == nil) {
@@ -427,7 +426,7 @@ - (void)start
                 }
 
                 const auto sample = [NSMutableDictionary<NSString *, id> dictionary];
-                sample[@"relative_timestamp_ns"] =
+                sample[@"elapsed_since_start_ns"] =
                     [@(getDurationNs(strongSelf->_startTimestamp, backtrace.absoluteTimestamp))
                         stringValue];
                 sample[@"thread_id"] = threadID;
@@ -475,7 +474,7 @@ - (void)stop
 
         _profiler->stopSampling();
         _endTimestamp = getAbsoluteTime();
-        _endDate = [NSDate date];
+        _endDate = [SentryCurrentDate date];
         SENTRY_LOG_DEBUG(@"Stopped profiler %@ at system time: %llu.", self, _endTimestamp);
     }
 }
@@ -486,6 +485,7 @@ - (void)captureEnvelope
     @synchronized(self) {
         profile = [_profile mutableCopy];
     }
+    profile[@"version"] = @"1";
     const auto debugImages = [NSMutableArray<NSDictionary<NSString *, id> *> new];
     const auto debugMeta = [_debugImageProvider getDebugImages];
     for (SentryDebugMeta *debugImage in debugMeta) {
@@ -522,6 +522,9 @@ - (void)captureEnvelope
     const auto profileDuration = getDurationNs(_startTimestamp, _endTimestamp);
     profile[@"duration_ns"] = [@(profileDuration) stringValue];
     profile[@"truncation_reason"] = profilerTruncationReasonName(_truncationReason);
+    profile[@"platform"] = _transactions.firstObject.platform;
+    profile[@"environment"] = _hub.scope.environmentString ?: _hub.getClient.options.environment ?: kSentryDefaultEnvironment;
+    profile[@"timestamp"] = [[SentryCurrentDate date] sentry_toIso8601String];
 
     const auto bundle = NSBundle.mainBundle;
     profile[@"release"] =
@@ -569,8 +572,8 @@ - (void)captureEnvelope
 #    endif // SENTRY_HAS_UIKIT
 
     // populate info from all transactions that occurred while profiler was running
-    profile[@"platform"] = _transactions.firstObject.platform;
     auto transactionsInfo = [NSMutableArray array];
+    NSString *mainThreadID = [profile[@"profile"][@"samples"] firstObject][@"thread_id"];
     for (SentryTransaction *transaction in _transactions) {
         const auto relativeStart =
             [NSString stringWithFormat:@"%llu",
@@ -585,12 +588,15 @@ - (void)captureEnvelope
                           : (unsigned long long)(
                               [transaction.timestamp timeIntervalSinceDate:_startDate] * 1e9)];
         [transactionsInfo addObject:@{
-            @"environment" : _hub.scope.environmentString ?: _hub.getClient.options.environment ?: kSentryDefaultEnvironment,
             @"id" : transaction.eventId.sentryIdString,
             @"trace_id" : transaction.trace.context.traceId.sentryIdString,
             @"name" : transaction.transaction,
             @"relative_start_ns" : relativeStart,
-            @"relative_end_ns" : relativeEnd
+            @"relative_end_ns" : relativeEnd,
+            @"active_thread_id" :
+                mainThreadID // TODO: we are just using the main thread ID for all transactions to
+                             // fix a backend validation error, but this needs to be gathered from
+                             // transaction starts in their contexts and carried forward to here
         }];
     }
     profile[@"transactions"] = transactionsInfo;
diff --git a/Sources/Sentry/include/NSDate+SentryExtras.h b/Sources/Sentry/include/NSDate+SentryExtras.h
index 7993ae072ee..c6257c8c1ec 100644
--- a/Sources/Sentry/include/NSDate+SentryExtras.h
+++ b/Sources/Sentry/include/NSDate+SentryExtras.h
@@ -5,7 +5,7 @@ NS_ASSUME_NONNULL_BEGIN
 @interface
 NSDate (SentryExtras)
 
-+ (NSDate *)sentry_fromIso8601String:(NSString *)string;
++ (NSDate *)sentry_fromIso8601String:(NSString *)string NS_SWIFT_NAME(sentry_from(iso8601String:));
 
 - (NSString *)sentry_toIso8601String;
 
diff --git a/Tests/SentryTests/Profiling/SentryProfilerSwiftTests.swift b/Tests/SentryTests/Profiling/SentryProfilerSwiftTests.swift
index 8c463522a92..188abdcecba 100644
--- a/Tests/SentryTests/Profiling/SentryProfilerSwiftTests.swift
+++ b/Tests/SentryTests/Profiling/SentryProfilerSwiftTests.swift
@@ -240,6 +240,14 @@ private extension SentryProfilerSwiftTests {
 
     func assertValidProfileData(data: Data, transactionEnvironment: String = kSentryDefaultEnvironment, numberOfTransactions: Int = 1, shouldTimeout: Bool = false) {
         let profile = try! JSONSerialization.jsonObject(with: data) as! [String: Any]
+
+        XCTAssertNotNil(profile["version"])
+        if let timestampString = profile["timestamp"] as? String {
+            XCTAssertNotNil(NSDate.sentry_from(iso8601String: timestampString))
+        } else {
+            XCTFail("Expected a top-level timestamp")
+        }
+
         let device = profile["device"] as? [String: Any?]
         XCTAssertNotNil(device)
         XCTAssertEqual("Apple", device!["manufacturer"] as! String)
@@ -259,6 +267,8 @@ private extension SentryProfilerSwiftTests {
 
         XCTAssertEqual("cocoa", profile["platform"] as! String)
 
+        XCTAssertEqual(transactionEnvironment, profile["environment"] as! String)
+
         let version = Bundle.main.object(forInfoDictionaryKey: kCFBundleVersionKey as String) ?? "(null)"
         let build = Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString") ?? "(null)"
         let releaseString = "\(version) (\(build))"
@@ -275,12 +285,11 @@ private extension SentryProfilerSwiftTests {
         XCTAssertGreaterThan((firstImage["image_size"] as! Int), 0)
         XCTAssertEqual(firstImage["type"] as! String, "macho")
 
-        let sampledProfile = profile["sampled_profile"] as! [String: Any]
+        let sampledProfile = profile["profile"] as! [String: Any]
         let threadMetadata = sampledProfile["thread_metadata"] as! [String: [String: Any]]
         let queueMetadata = sampledProfile["queue_metadata"] as! [String: Any]
         XCTAssertFalse(threadMetadata.isEmpty)
         XCTAssertFalse(threadMetadata.values.compactMap { $0["priority"] }.filter { ($0 as! Int) > 0 }.isEmpty)
-        XCTAssertFalse(threadMetadata.values.filter { $0["is_main_thread"] as? Bool == true }.isEmpty)
         XCTAssertFalse(queueMetadata.isEmpty)
         XCTAssertFalse(((queueMetadata.first?.value as! [String: Any])["label"] as! String).isEmpty)
 
@@ -316,13 +325,15 @@ private extension SentryProfilerSwiftTests {
             if let traceIDString = transaction["trace_id"] {
                 XCTAssertNotEqual(SentryId.empty, SentryId(uuidString: traceIDString))
             }
-            XCTAssertEqual(transactionEnvironment, transaction["environment"])
             XCTAssertNotNil(transaction["trace_id"])
             XCTAssertNotNil(transaction["relative_start_ns"])
             XCTAssertNotNil(transaction["relative_end_ns"])
+            XCTAssertNotNil(transaction["active_thread_id"])
         }
 
         for sample in samples {
+            XCTAssertNotNil(sample["elapsed_since_start_ns"] as! String)
+            XCTAssertNotNil(sample["thread_id"])
             XCTAssertNotNil(stacks[sample["stack_id"] as! Int])
         }