diff --git a/backend/pom.xml b/backend/pom.xml
index 913a07f..d367cca 100644
--- a/backend/pom.xml
+++ b/backend/pom.xml
@@ -40,17 +40,18 @@
             <artifactId>quarkus-hibernate-orm-panache</artifactId>
         </dependency>
         <dependency>
-            <groupId>io.quarkus</groupId>
-            <artifactId>quarkus-jdbc-mariadb</artifactId>
+            <groupId>org.xerial</groupId>
+            <artifactId>sqlite-jdbc</artifactId>
+            <version>3.47.1.0</version>
+        </dependency>
+        <dependency>
+            <groupId>org.hibernate.orm</groupId>
+            <artifactId>hibernate-community-dialects</artifactId>
         </dependency>
         <dependency>
             <groupId>io.quarkus</groupId>
             <artifactId>quarkus-flyway</artifactId>
         </dependency>
-        <dependency>
-            <groupId>org.flywaydb</groupId>
-            <artifactId>flyway-mysql</artifactId>
-        </dependency>
         <dependency>
             <groupId>io.quarkus</groupId>
             <artifactId>quarkus-arc</artifactId>
diff --git a/backend/src/main/resources/application.properties b/backend/src/main/resources/application.properties
index e96afc2..434bd7a 100644
--- a/backend/src/main/resources/application.properties
+++ b/backend/src/main/resources/application.properties
@@ -1,19 +1,23 @@
-# Datasource
-quarkus.datasource.db-kind=mariadb
-quarkus.datasource.username=strichliste
-quarkus.datasource.password=strichliste
-quarkus.datasource.jdbc.url=jdbc:mariadb://localhost:3306/strichliste
+# Datasource – SQLite
+quarkus.datasource.db-kind=other
+quarkus.datasource.jdbc.driver=org.sqlite.JDBC
+quarkus.datasource.jdbc.url=jdbc:sqlite:${DB_PATH:/data/qaffee.db}
 
-# Agroal connection pool – evict stale connections after a DB restart
-quarkus.datasource.jdbc.background-validation-interval=30S
-quarkus.datasource.jdbc.idle-removal-interval=5M
-quarkus.datasource.jdbc.max-lifetime=10M
+# Connection Pool (SQLite: single writer)
+quarkus.datasource.jdbc.min-size=1
+quarkus.datasource.jdbc.max-size=1
 
 # Hibernate
+quarkus.hibernate-orm.dialect=org.hibernate.community.dialect.SQLiteDialect
 quarkus.hibernate-orm.database.generation=none
 
 # Flyway
 quarkus.flyway.migrate-at-start=true
+# Baseline: treat V1-V4 as already applied when no history table exists (post-migration start)
+quarkus.flyway.baseline-on-migrate=true
+quarkus.flyway.baseline-version=4
+# Checksums der MariaDB-Dateien passen nicht mehr zu den SQLite-kompatiblen Versionen
+quarkus.flyway.validate-on-migrate=false
 
 # CORS ist deaktiviert, da alle Anfragen über den SvelteKit-Proxy laufen
 quarkus.http.cors=false
diff --git a/backend/src/main/resources/db/migration/V1__initial_schema.sql b/backend/src/main/resources/db/migration/V1__initial_schema.sql
index b6cdbe4..b0435af 100644
--- a/backend/src/main/resources/db/migration/V1__initial_schema.sql
+++ b/backend/src/main/resources/db/migration/V1__initial_schema.sql
@@ -1,49 +1,50 @@
 CREATE TABLE company (
-    id BIGINT AUTO_INCREMENT PRIMARY KEY,
+    id INTEGER PRIMARY KEY,
     name VARCHAR(255) NOT NULL,
-    active BOOLEAN NOT NULL DEFAULT TRUE,
-    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
-) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+    active TINYINT(1) NOT NULL DEFAULT 1,
+    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
 
 CREATE TABLE employee (
-    id BIGINT AUTO_INCREMENT PRIMARY KEY,
+    id INTEGER PRIMARY KEY,
     company_id BIGINT NOT NULL,
     first_name VARCHAR(255) NOT NULL,
     last_name VARCHAR(255) NOT NULL,
-    active BOOLEAN NOT NULL DEFAULT TRUE,
-    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
-    CONSTRAINT fk_employee_company FOREIGN KEY (company_id) REFERENCES company(id)
-) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+    active TINYINT(1) NOT NULL DEFAULT 1,
+    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    FOREIGN KEY (company_id) REFERENCES company(id)
+);
 
 CREATE TABLE product (
-    id BIGINT AUTO_INCREMENT PRIMARY KEY,
+    id INTEGER PRIMARY KEY,
     name VARCHAR(255) NOT NULL,
     price_cents INT NOT NULL DEFAULT 0,
-    icon_placeholder VARCHAR(50) DEFAULT 'coffee',
-    active BOOLEAN NOT NULL DEFAULT TRUE,
-    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
-) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+    icon_placeholder VARCHAR(255) DEFAULT 'coffee',
+    active TINYINT(1) NOT NULL DEFAULT 1,
+    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
 
 CREATE TABLE tally_entry (
-    id BIGINT AUTO_INCREMENT PRIMARY KEY,
+    id INTEGER PRIMARY KEY,
     employee_id BIGINT NOT NULL,
     product_id BIGINT NOT NULL,
     month_key VARCHAR(7) NOT NULL,
-    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
-    CONSTRAINT fk_tally_employee FOREIGN KEY (employee_id) REFERENCES employee(id),
-    CONSTRAINT fk_tally_product FOREIGN KEY (product_id) REFERENCES product(id),
-    INDEX idx_tally_month (month_key),
-    INDEX idx_tally_employee_month (employee_id, month_key)
-) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    FOREIGN KEY (employee_id) REFERENCES employee(id),
+    FOREIGN KEY (product_id) REFERENCES product(id)
+);
+
+CREATE INDEX idx_tally_month ON tally_entry(month_key);
+CREATE INDEX idx_tally_employee_month ON tally_entry(employee_id, month_key);
 
 CREATE TABLE access_link (
-    id BIGINT AUTO_INCREMENT PRIMARY KEY,
+    id INTEGER PRIMARY KEY,
     token VARCHAR(64) NOT NULL UNIQUE,
-    role VARCHAR(20) NOT NULL,
+    role VARCHAR(50) NOT NULL,
     company_id BIGINT,
-    description VARCHAR(255),
-    active BOOLEAN NOT NULL DEFAULT TRUE,
-    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
-    CONSTRAINT fk_access_link_company FOREIGN KEY (company_id) REFERENCES company(id),
-    CONSTRAINT chk_role CHECK (role IN ('COMPANY_ADMIN', 'PROVIDER_ADMIN'))
-) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+    description TEXT,
+    active TINYINT(1) NOT NULL DEFAULT 1,
+    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    FOREIGN KEY (company_id) REFERENCES company(id),
+    CHECK (role IN ('COMPANY_ADMIN', 'PROVIDER_ADMIN'))
+);
diff --git a/backend/src/main/resources/db/migration/V3__company_logo.sql b/backend/src/main/resources/db/migration/V3__company_logo.sql
index b35f674..581fc9b 100644
--- a/backend/src/main/resources/db/migration/V3__company_logo.sql
+++ b/backend/src/main/resources/db/migration/V3__company_logo.sql
@@ -1,2 +1,2 @@
 ALTER TABLE company ADD COLUMN logo MEDIUMBLOB;
-ALTER TABLE company ADD COLUMN logo_content_type VARCHAR(50);
+ALTER TABLE company ADD COLUMN logo_content_type VARCHAR(255);
diff --git a/data/qaffee.db b/data/qaffee.db
new file mode 100644
index 0000000..b40b3b8
Binary files /dev/null and b/data/qaffee.db differ
diff --git a/docker-compose.yml b/docker-compose.yml
index f3dfab0..cbe9c44 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -1,34 +1,12 @@
 version: "3"
-volumes:
-  db-data:
 services:
-  db:
-    image: mariadb:11.4.4
-    container_name: qaffee-db
-    restart: always
-    command: --log-warnings=3
-    environment:
-      - "MARIADB_ROOT_PASSWORD=rootpassword"
-      - "MARIADB_DATABASE=strichliste"
-      - "MARIADB_USER=strichliste"
-      - "MARIADB_PASSWORD=strichliste"
-    volumes:
-      - db-data:/var/lib/mysql
-    healthcheck:
-      test: ["CMD", "healthcheck.sh", "--connect", "--innodb_initialized"]
-      interval: 10s
-      timeout: 5s
-      retries: 5
-    networks:
-      - traefik-net
   backend:
     build: ./backend
     container_name: qaffee-backend
     environment:
-      - "QUARKUS_DATASOURCE_JDBC_URL=jdbc:mariadb://db:3306/strichliste"
-      - "QUARKUS_DATASOURCE_USERNAME=strichliste"
-      - "QUARKUS_DATASOURCE_PASSWORD=strichliste"
       - "QUARKUS_HTTP_CORS_ORIGINS=https://qaffee.cloud.aquantico.de"
+    volumes:
+      - ./data:/data
     labels:
       traefik.enable: "true"
       traefik.docker.network: "traefik-net"
@@ -37,9 +15,6 @@ services:
       traefik.http.routers.qaffee-backend.tls: "true"
       traefik.http.routers.qaffee-backend.tls.certresolver: "myresolver"
       traefik.http.services.qaffee-backend.loadbalancer.server.port: 8080
-    depends_on:
-      db:
-        condition: service_healthy
     networks:
       - traefik-net
   frontend:
@@ -61,22 +36,6 @@ services:
       - backend
     networks:
       - traefik-net
-  backup:
-    image: mariadb:11.4.4
-    container_name: qaffee-backup
-    environment:
-      - "MARIADB_HOST=db"
-      - "MARIADB_USER=strichliste"
-      - "MARIADB_PASSWORD=strichliste"
-    volumes:
-      - ./backups:/backups
-      - ./db/backup.sh:/backup.sh
-    entrypoint: ["/bin/bash", "/backup.sh"]
-    depends_on:
-      db:
-        condition: service_healthy
-    networks:
-      - traefik-net
 networks:
   traefik-net:
-    external: false
\ No newline at end of file
+    external: false