diff --git a/DevLog/Data/Repository/AuthenticationRepositoryImpl.swift b/DevLog/Data/Repository/AuthenticationRepositoryImpl.swift
index ce02d5d6..a96b2862 100644
--- a/DevLog/Data/Repository/AuthenticationRepositoryImpl.swift
+++ b/DevLog/Data/Repository/AuthenticationRepositoryImpl.swift
@@ -27,16 +27,29 @@ final class AuthenticationRepositoryImpl: AuthenticationRepository {
     }
 
     func signIn(_ provider: AuthProvider) async throws {
-        let response: AuthDataResponse
-        switch provider {
-        case .apple:
-            response = try await appleAuthService.signIn()
-        case .github:
-            response = try await githubAuthService.signIn()
-        case .google:
-            response = try await googleAuthService.signIn()
+        authService.beginSignIn()
+
+        do {
+            let response: AuthDataResponse
+            switch provider {
+            case .apple:
+                response = try await appleAuthService.signIn()
+            case .github:
+                response = try await githubAuthService.signIn()
+            case .google:
+                response = try await googleAuthService.signIn()
+            }
+
+            try await userService.upsertUser(response)
+            authService.completeSignIn()
+        } catch {
+            if authService.uid != nil {
+                try? await authService.clearCurrentSession()
+            }
+
+            authService.cancelSignIn()
+            throw error
         }
-        try await userService.upsertUser(response)
     }
 
     func signOut() async throws {
diff --git a/DevLog/Infra/Service/AuthService.swift b/DevLog/Infra/Service/AuthService.swift
index e0a27b9a..6b5cd59a 100644
--- a/DevLog/Infra/Service/AuthService.swift
+++ b/DevLog/Infra/Service/AuthService.swift
@@ -16,6 +16,7 @@ final class AuthService {
     private let logger = Logger(category: "AuthService")
     private let subject = CurrentValueSubject<Bool, Never>(Auth.auth().currentUser != nil)
     private var handler: AuthStateDidChangeListenerHandle?
+    private var isCompletingSignIn = false
 
     var uid: String? {
         Auth.auth().currentUser?.uid
@@ -27,9 +28,16 @@ final class AuthService {
 
     init() {
         handler = Auth.auth().addStateDidChangeListener { [weak self] _, user in
+            guard let self else { return }
             let signedIn = user != nil
-            self?.logger.info("Firebase auth state changed. signedIn: \(signedIn)")
-            self?.subject.send(signedIn)
+            self.logger.info("Firebase auth state changed. signedIn: \(signedIn)")
+
+            if signedIn && self.isCompletingSignIn {
+                self.logger.info("Delaying signed-in publication until user bootstrap finishes")
+                return
+            }
+
+            self.subject.send(signedIn)
         }
     }
 
@@ -42,6 +50,24 @@ final class AuthService {
         subject.eraseToAnyPublisher()
     }
 
+    func beginSignIn() {
+        logger.info("Beginning sign-in bootstrap")
+        isCompletingSignIn = true
+        subject.send(false)
+    }
+
+    func completeSignIn() {
+        logger.info("Completing sign-in bootstrap")
+        isCompletingSignIn = false
+        subject.send(Auth.auth().currentUser != nil)
+    }
+
+    func cancelSignIn() {
+        logger.info("Cancelling sign-in bootstrap")
+        isCompletingSignIn = false
+        subject.send(Auth.auth().currentUser != nil)
+    }
+
     func getProviderID() async throws -> String? {
         logger.info("Fetching current provider ID")