diff --git a/src/services/platforms/CapacitorPlatformService.ts b/src/services/platforms/CapacitorPlatformService.ts
index ed483a8d..5c14d285 100644
--- a/src/services/platforms/CapacitorPlatformService.ts
+++ b/src/services/platforms/CapacitorPlatformService.ts
@@ -6,8 +6,20 @@ import {
 import { Filesystem, Directory, Encoding } from "@capacitor/filesystem";
 import { Camera, CameraResultType, CameraSource } from "@capacitor/camera";
 import { Share } from "@capacitor/share";
+import {
+  SQLiteConnection,
+  SQLiteDBConnection,
+  CapacitorSQLite,
+  Changes,
+} from "@capacitor-community/sqlite";
 import { logger } from "../../utils/logger";
-import { QueryExecResult } from "@/interfaces/database";
+import { QueryExecResult, SqlValue } from "@/interfaces/database";
+import { DEFAULT_ENDORSER_API_SERVER } from "@/constants/app";
+
+interface Migration {
+  name: string;
+  sql: string;
+}
 
 /**
  * Platform service implementation for Capacitor (mobile) platform.
@@ -15,8 +27,168 @@ import { QueryExecResult } from "@/interfaces/database";
  * - File system operations
  * - Camera and image picker
  * - Platform-specific features
+ * - SQLite database operations
  */
 export class CapacitorPlatformService implements PlatformService {
+  private sqlite: SQLiteConnection;
+  private db: SQLiteDBConnection | null = null;
+  private dbName = "timesafari.db";
+  private initialized = false;
+
+  constructor() {
+    this.sqlite = new SQLiteConnection(CapacitorSQLite);
+  }
+
+  private async initializeDatabase(): Promise<void> {
+    if (this.initialized) {
+      return;
+    }
+
+    try {
+      // Create/Open database
+      this.db = await this.sqlite.createConnection(
+        this.dbName,
+        false,
+        "no-encryption",
+        1,
+        false,
+      );
+
+      await this.db.open();
+
+      // Set journal mode to WAL for better performance
+      await this.db.execute("PRAGMA journal_mode=WAL;");
+
+      // Run migrations
+      await this.runMigrations();
+
+      this.initialized = true;
+      logger.log("SQLite database initialized successfully");
+    } catch (error) {
+      logger.error("Error initializing SQLite database:", error);
+      throw new Error("Failed to initialize database");
+    }
+  }
+
+  private async runMigrations(): Promise<void> {
+    if (!this.db) {
+      throw new Error("Database not initialized");
+    }
+
+    // Create migrations table if it doesn't exist
+    await this.db.execute(`
+      CREATE TABLE IF NOT EXISTS migrations (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        name TEXT NOT NULL UNIQUE,
+        executed_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+      );
+    `);
+
+    // Get list of executed migrations
+    const result = await this.db.query("SELECT name FROM migrations;");
+    const executedMigrations = new Set(
+      result.values?.map((row) => row[0]) || [],
+    );
+
+    // Run pending migrations in order
+    const migrations: Migration[] = [
+      {
+        name: "001_initial",
+        sql: `
+          CREATE TABLE IF NOT EXISTS accounts (
+            id INTEGER PRIMARY KEY AUTOINCREMENT,
+            dateCreated TEXT NOT NULL,
+            derivationPath TEXT,
+            did TEXT NOT NULL,
+            identityEncrBase64 TEXT,
+            mnemonicEncrBase64 TEXT,
+            passkeyCredIdHex TEXT,
+            publicKeyHex TEXT NOT NULL
+          );
+
+          CREATE INDEX IF NOT EXISTS idx_accounts_did ON accounts(did);
+
+          CREATE TABLE IF NOT EXISTS secret (
+            id INTEGER PRIMARY KEY AUTOINCREMENT,
+            secretBase64 TEXT NOT NULL
+          );
+
+          CREATE TABLE IF NOT EXISTS settings (
+            id INTEGER PRIMARY KEY AUTOINCREMENT,
+            accountDid TEXT,
+            activeDid TEXT,
+            apiServer TEXT,
+            filterFeedByNearby BOOLEAN,
+            filterFeedByVisible BOOLEAN,
+            finishedOnboarding BOOLEAN,
+            firstName TEXT,
+            hideRegisterPromptOnNewContact BOOLEAN,
+            isRegistered BOOLEAN,
+            lastName TEXT,
+            lastAckedOfferToUserJwtId TEXT,
+            lastAckedOfferToUserProjectsJwtId TEXT,
+            lastNotifiedClaimId TEXT,
+            lastViewedClaimId TEXT,
+            notifyingNewActivityTime TEXT,
+            notifyingReminderMessage TEXT,
+            notifyingReminderTime TEXT,
+            partnerApiServer TEXT,
+            passkeyExpirationMinutes INTEGER,
+            profileImageUrl TEXT,
+            searchBoxes TEXT,
+            showContactGivesInline BOOLEAN,
+            showGeneralAdvanced BOOLEAN,
+            showShortcutBvc BOOLEAN,
+            vapid TEXT,
+            warnIfProdServer BOOLEAN,
+            warnIfTestServer BOOLEAN,
+            webPushServer TEXT
+          );
+
+          CREATE INDEX IF NOT EXISTS idx_settings_accountDid ON settings(accountDid);
+
+          INSERT INTO settings (id, apiServer) VALUES (1, '${DEFAULT_ENDORSER_API_SERVER}');
+
+          CREATE TABLE IF NOT EXISTS contacts (
+            id INTEGER PRIMARY KEY AUTOINCREMENT,
+            did TEXT NOT NULL,
+            name TEXT,
+            contactMethods TEXT,
+            nextPubKeyHashB64 TEXT,
+            notes TEXT,
+            profileImageUrl TEXT,
+            publicKeyBase64 TEXT,
+            seesMe BOOLEAN,
+            registered BOOLEAN
+          );
+
+          CREATE INDEX IF NOT EXISTS idx_contacts_did ON contacts(did);
+          CREATE INDEX IF NOT EXISTS idx_contacts_name ON contacts(name);
+
+          CREATE TABLE IF NOT EXISTS logs (
+            date TEXT PRIMARY KEY,
+            message TEXT NOT NULL
+          );
+
+          CREATE TABLE IF NOT EXISTS temp (
+            id TEXT PRIMARY KEY,
+            blobB64 TEXT
+          );
+        `,
+      },
+    ];
+
+    for (const migration of migrations) {
+      if (!executedMigrations.has(migration.name)) {
+        await this.db.execute(migration.sql);
+        await this.db.run("INSERT INTO migrations (name) VALUES (?)", [
+          migration.name,
+        ]);
+        logger.log(`Migration ${migration.name} executed successfully`);
+      }
+    }
+  }
+
   /**
    * Gets the capabilities of the Capacitor platform
    * @returns Platform capabilities object
@@ -478,13 +650,54 @@ export class CapacitorPlatformService implements PlatformService {
     return Promise.resolve();
   }
 
-  dbQuery(sql: string, params?: unknown[]): Promise<QueryExecResult> {
-    throw new Error("Not implemented for " + sql + " with params " + params);
+  /**
+   * @see PlatformService.dbQuery
+   */
+  async dbQuery(sql: string, params?: unknown[]): Promise<QueryExecResult> {
+    await this.initializeDatabase();
+    if (!this.db) {
+      throw new Error("Database not initialized");
+    }
+
+    try {
+      const result = await this.db.query(sql, params || []);
+      const values = result.values || [];
+      return {
+        columns: [], // SQLite plugin doesn't provide column names in query result
+        values: values as SqlValue[][],
+      };
+    } catch (error) {
+      logger.error("Error executing query:", error);
+      throw new Error(
+        `Database query failed: ${error instanceof Error ? error.message : String(error)}`,
+      );
+    }
   }
-  dbExec(
+
+  /**
+   * @see PlatformService.dbExec
+   */
+  async dbExec(
     sql: string,
     params?: unknown[],
   ): Promise<{ changes: number; lastId?: number }> {
-    throw new Error("Not implemented for " + sql + " with params " + params);
+    await this.initializeDatabase();
+    if (!this.db) {
+      throw new Error("Database not initialized");
+    }
+
+    try {
+      const result = await this.db.run(sql, params || []);
+      const changes = result.changes as Changes;
+      return {
+        changes: changes?.changes || 0,
+        lastId: changes?.lastId,
+      };
+    } catch (error) {
+      logger.error("Error executing statement:", error);
+      throw new Error(
+        `Database execution failed: ${error instanceof Error ? error.message : String(error)}`,
+      );
+    }
   }
 }
diff --git a/src/services/platforms/ElectronPlatformService.ts b/src/services/platforms/ElectronPlatformService.ts
index 07b6d5ed..5bdd455f 100644
--- a/src/services/platforms/ElectronPlatformService.ts
+++ b/src/services/platforms/ElectronPlatformService.ts
@@ -4,21 +4,188 @@ import {
   PlatformCapabilities,
 } from "../PlatformService";
 import { logger } from "../../utils/logger";
-import { QueryExecResult } from "@/interfaces/database";
+import { QueryExecResult, SqlValue } from "@/interfaces/database";
+import {
+  SQLiteConnection,
+  SQLiteDBConnection,
+  CapacitorSQLite,
+  Changes,
+} from "@capacitor-community/sqlite";
+import { DEFAULT_ENDORSER_API_SERVER } from "@/constants/app";
+
+interface Migration {
+  name: string;
+  sql: string;
+}
 
 /**
  * Platform service implementation for Electron (desktop) platform.
- * Note: This is a placeholder implementation with most methods currently unimplemented.
- * Implements the PlatformService interface but throws "Not implemented" errors for most operations.
- *
- * @remarks
- * This service is intended for desktop application functionality through Electron.
- * Future implementations should provide:
- * - Native file system access
- * - Desktop camera integration
- * - System-level features
+ * Provides native desktop functionality through Electron and Capacitor plugins for:
+ * - File system operations (TODO)
+ * - Camera integration (TODO)
+ * - SQLite database operations
+ * - System-level features (TODO)
  */
 export class ElectronPlatformService implements PlatformService {
+  private sqlite: SQLiteConnection;
+  private db: SQLiteDBConnection | null = null;
+  private dbName = "timesafari.db";
+  private initialized = false;
+
+  constructor() {
+    this.sqlite = new SQLiteConnection(CapacitorSQLite);
+  }
+
+  private async initializeDatabase(): Promise<void> {
+    if (this.initialized) {
+      return;
+    }
+
+    try {
+      // Create/Open database
+      this.db = await this.sqlite.createConnection(
+        this.dbName,
+        false,
+        "no-encryption",
+        1,
+        false,
+      );
+
+      await this.db.open();
+
+      // Set journal mode to WAL for better performance
+      await this.db.execute("PRAGMA journal_mode=WAL;");
+
+      // Run migrations
+      await this.runMigrations();
+
+      this.initialized = true;
+      logger.log("SQLite database initialized successfully");
+    } catch (error) {
+      logger.error("Error initializing SQLite database:", error);
+      throw new Error("Failed to initialize database");
+    }
+  }
+
+  private async runMigrations(): Promise<void> {
+    if (!this.db) {
+      throw new Error("Database not initialized");
+    }
+
+    // Create migrations table if it doesn't exist
+    await this.db.execute(`
+      CREATE TABLE IF NOT EXISTS migrations (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        name TEXT NOT NULL UNIQUE,
+        executed_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+      );
+    `);
+
+    // Get list of executed migrations
+    const result = await this.db.query("SELECT name FROM migrations;");
+    const executedMigrations = new Set(
+      result.values?.map((row) => row[0]) || [],
+    );
+
+    // Run pending migrations in order
+    const migrations: Migration[] = [
+      {
+        name: "001_initial",
+        sql: `
+          CREATE TABLE IF NOT EXISTS accounts (
+            id INTEGER PRIMARY KEY AUTOINCREMENT,
+            dateCreated TEXT NOT NULL,
+            derivationPath TEXT,
+            did TEXT NOT NULL,
+            identityEncrBase64 TEXT,
+            mnemonicEncrBase64 TEXT,
+            passkeyCredIdHex TEXT,
+            publicKeyHex TEXT NOT NULL
+          );
+
+          CREATE INDEX IF NOT EXISTS idx_accounts_did ON accounts(did);
+
+          CREATE TABLE IF NOT EXISTS secret (
+            id INTEGER PRIMARY KEY AUTOINCREMENT,
+            secretBase64 TEXT NOT NULL
+          );
+
+          CREATE TABLE IF NOT EXISTS settings (
+            id INTEGER PRIMARY KEY AUTOINCREMENT,
+            accountDid TEXT,
+            activeDid TEXT,
+            apiServer TEXT,
+            filterFeedByNearby BOOLEAN,
+            filterFeedByVisible BOOLEAN,
+            finishedOnboarding BOOLEAN,
+            firstName TEXT,
+            hideRegisterPromptOnNewContact BOOLEAN,
+            isRegistered BOOLEAN,
+            lastName TEXT,
+            lastAckedOfferToUserJwtId TEXT,
+            lastAckedOfferToUserProjectsJwtId TEXT,
+            lastNotifiedClaimId TEXT,
+            lastViewedClaimId TEXT,
+            notifyingNewActivityTime TEXT,
+            notifyingReminderMessage TEXT,
+            notifyingReminderTime TEXT,
+            partnerApiServer TEXT,
+            passkeyExpirationMinutes INTEGER,
+            profileImageUrl TEXT,
+            searchBoxes TEXT,
+            showContactGivesInline BOOLEAN,
+            showGeneralAdvanced BOOLEAN,
+            showShortcutBvc BOOLEAN,
+            vapid TEXT,
+            warnIfProdServer BOOLEAN,
+            warnIfTestServer BOOLEAN,
+            webPushServer TEXT
+          );
+
+          CREATE INDEX IF NOT EXISTS idx_settings_accountDid ON settings(accountDid);
+
+          INSERT INTO settings (id, apiServer) VALUES (1, '${DEFAULT_ENDORSER_API_SERVER}');
+
+          CREATE TABLE IF NOT EXISTS contacts (
+            id INTEGER PRIMARY KEY AUTOINCREMENT,
+            did TEXT NOT NULL,
+            name TEXT,
+            contactMethods TEXT,
+            nextPubKeyHashB64 TEXT,
+            notes TEXT,
+            profileImageUrl TEXT,
+            publicKeyBase64 TEXT,
+            seesMe BOOLEAN,
+            registered BOOLEAN
+          );
+
+          CREATE INDEX IF NOT EXISTS idx_contacts_did ON contacts(did);
+          CREATE INDEX IF NOT EXISTS idx_contacts_name ON contacts(name);
+
+          CREATE TABLE IF NOT EXISTS logs (
+            date TEXT PRIMARY KEY,
+            message TEXT NOT NULL
+          );
+
+          CREATE TABLE IF NOT EXISTS temp (
+            id TEXT PRIMARY KEY,
+            blobB64 TEXT
+          );
+        `,
+      },
+    ];
+
+    for (const migration of migrations) {
+      if (!executedMigrations.has(migration.name)) {
+        await this.db.execute(migration.sql);
+        await this.db.run("INSERT INTO migrations (name) VALUES (?)", [
+          migration.name,
+        ]);
+        logger.log(`Migration ${migration.name} executed successfully`);
+      }
+    }
+  }
+
   /**
    * Gets the capabilities of the Electron platform
    * @returns Platform capabilities object
@@ -56,6 +223,17 @@ export class ElectronPlatformService implements PlatformService {
     throw new Error("Not implemented");
   }
 
+  /**
+   * Writes content to a file and opens the system share dialog.
+   * @param _fileName - Name of the file to create
+   * @param _content - Content to write to the file
+   * @throws Error with "Not implemented" message
+   * @todo Implement using Electron's dialog and file system APIs
+   */
+  async writeAndShareFile(_fileName: string, _content: string): Promise<void> {
+    throw new Error("Not implemented");
+  }
+
   /**
    * Deletes a file from the filesystem.
    * @param _path - Path to the file to delete
@@ -110,13 +288,54 @@ export class ElectronPlatformService implements PlatformService {
     throw new Error("Not implemented");
   }
 
-  dbQuery(sql: string, params?: unknown[]): Promise<QueryExecResult> {
-    throw new Error("Not implemented for " + sql + " with params " + params);
+  /**
+   * @see PlatformService.dbQuery
+   */
+  async dbQuery(sql: string, params?: unknown[]): Promise<QueryExecResult> {
+    await this.initializeDatabase();
+    if (!this.db) {
+      throw new Error("Database not initialized");
+    }
+
+    try {
+      const result = await this.db.query(sql, params || []);
+      const values = result.values || [];
+      return {
+        columns: [], // SQLite plugin doesn't provide column names in query result
+        values: values as SqlValue[][],
+      };
+    } catch (error) {
+      logger.error("Error executing query:", error);
+      throw new Error(
+        `Database query failed: ${error instanceof Error ? error.message : String(error)}`,
+      );
+    }
   }
-  dbExec(
+
+  /**
+   * @see PlatformService.dbExec
+   */
+  async dbExec(
     sql: string,
     params?: unknown[],
   ): Promise<{ changes: number; lastId?: number }> {
-    throw new Error("Not implemented for " + sql + " with params " + params);
+    await this.initializeDatabase();
+    if (!this.db) {
+      throw new Error("Database not initialized");
+    }
+
+    try {
+      const result = await this.db.run(sql, params || []);
+      const changes = result.changes as Changes;
+      return {
+        changes: changes?.changes || 0,
+        lastId: changes?.lastId,
+      };
+    } catch (error) {
+      logger.error("Error executing statement:", error);
+      throw new Error(
+        `Database execution failed: ${error instanceof Error ? error.message : String(error)}`,
+      );
+    }
   }
 }