diff --git a/pixstrip-core/Cargo.toml b/pixstrip-core/Cargo.toml
index 2d09295..6afddc3 100644
--- a/pixstrip-core/Cargo.toml
+++ b/pixstrip-core/Cargo.toml
@@ -19,6 +19,7 @@ webp = "0.3"
 little_exif = "0.4"
 imageproc = "0.25"
 ab_glyph = "0.2"
+dirs = "6"
 
 [dev-dependencies]
 tempfile = "3"
diff --git a/pixstrip-core/src/lib.rs b/pixstrip-core/src/lib.rs
index 01259d6..e1e9952 100644
--- a/pixstrip-core/src/lib.rs
+++ b/pixstrip-core/src/lib.rs
@@ -7,6 +7,7 @@ pub mod loader;
 pub mod operations;
 pub mod pipeline;
 pub mod preset;
+pub mod storage;
 pub mod types;
 
 pub fn version() -> &'static str {
diff --git a/pixstrip-core/src/storage.rs b/pixstrip-core/src/storage.rs
new file mode 100644
index 0000000..31546cb
--- /dev/null
+++ b/pixstrip-core/src/storage.rs
@@ -0,0 +1,287 @@
+use std::path::{Path, PathBuf};
+
+use serde::{Deserialize, Serialize};
+
+use crate::config::AppConfig;
+use crate::error::{PixstripError, Result};
+use crate::preset::Preset;
+
+fn default_config_dir() -> PathBuf {
+    dirs::config_dir()
+        .unwrap_or_else(|| PathBuf::from("~/.config"))
+        .join("pixstrip")
+}
+
+fn sanitize_filename(name: &str) -> String {
+    name.chars()
+        .map(|c| match c {
+            '/' | '\\' | '<' | '>' | ':' | '"' | '|' | '?' | '*' => '_',
+            _ => c,
+        })
+        .collect()
+}
+
+// --- Preset Store ---
+
+pub struct PresetStore {
+    presets_dir: PathBuf,
+}
+
+impl PresetStore {
+    pub fn new() -> Self {
+        Self {
+            presets_dir: default_config_dir().join("presets"),
+        }
+    }
+
+    pub fn with_base_dir(base: &Path) -> Self {
+        Self {
+            presets_dir: base.join("presets"),
+        }
+    }
+
+    fn ensure_dir(&self) -> Result<()> {
+        std::fs::create_dir_all(&self.presets_dir).map_err(PixstripError::Io)
+    }
+
+    fn preset_path(&self, name: &str) -> PathBuf {
+        let filename = format!("{}.json", sanitize_filename(name));
+        self.presets_dir.join(filename)
+    }
+
+    pub fn save(&self, preset: &Preset) -> Result<()> {
+        self.ensure_dir()?;
+        let path = self.preset_path(&preset.name);
+        let json = serde_json::to_string_pretty(preset)
+            .map_err(|e| PixstripError::Preset(e.to_string()))?;
+        std::fs::write(&path, json).map_err(PixstripError::Io)
+    }
+
+    pub fn load(&self, name: &str) -> Result<Preset> {
+        let path = self.preset_path(name);
+        if !path.exists() {
+            return Err(PixstripError::Preset(format!(
+                "Preset '{}' not found",
+                name
+            )));
+        }
+        let data = std::fs::read_to_string(&path).map_err(PixstripError::Io)?;
+        serde_json::from_str(&data).map_err(|e| PixstripError::Preset(e.to_string()))
+    }
+
+    pub fn list(&self) -> Result<Vec<Preset>> {
+        if !self.presets_dir.exists() {
+            return Ok(Vec::new());
+        }
+
+        let mut presets = Vec::new();
+        for entry in std::fs::read_dir(&self.presets_dir).map_err(PixstripError::Io)? {
+            let entry = entry.map_err(PixstripError::Io)?;
+            let path = entry.path();
+            if path.extension().and_then(|e| e.to_str()) == Some("json") {
+                let data = std::fs::read_to_string(&path).map_err(PixstripError::Io)?;
+                if let Ok(preset) = serde_json::from_str::<Preset>(&data) {
+                    presets.push(preset);
+                }
+            }
+        }
+        presets.sort_by(|a, b| a.name.cmp(&b.name));
+        Ok(presets)
+    }
+
+    pub fn delete(&self, name: &str) -> Result<()> {
+        let path = self.preset_path(name);
+        if !path.exists() {
+            return Err(PixstripError::Preset(format!(
+                "Preset '{}' not found",
+                name
+            )));
+        }
+        std::fs::remove_file(&path).map_err(PixstripError::Io)
+    }
+
+    pub fn export_to_file(&self, preset: &Preset, path: &Path) -> Result<()> {
+        let json = serde_json::to_string_pretty(preset)
+            .map_err(|e| PixstripError::Preset(e.to_string()))?;
+        std::fs::write(path, json).map_err(PixstripError::Io)
+    }
+
+    pub fn import_from_file(&self, path: &Path) -> Result<Preset> {
+        let data = std::fs::read_to_string(path).map_err(PixstripError::Io)?;
+        let mut preset: Preset =
+            serde_json::from_str(&data).map_err(|e| PixstripError::Preset(e.to_string()))?;
+        preset.is_custom = true;
+        Ok(preset)
+    }
+}
+
+impl Default for PresetStore {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+// --- Config Store ---
+
+pub struct ConfigStore {
+    config_path: PathBuf,
+}
+
+impl ConfigStore {
+    pub fn new() -> Self {
+        Self {
+            config_path: default_config_dir().join("config.json"),
+        }
+    }
+
+    pub fn with_base_dir(base: &Path) -> Self {
+        Self {
+            config_path: base.join("config.json"),
+        }
+    }
+
+    pub fn save(&self, config: &AppConfig) -> Result<()> {
+        if let Some(parent) = self.config_path.parent() {
+            std::fs::create_dir_all(parent).map_err(PixstripError::Io)?;
+        }
+        let json = serde_json::to_string_pretty(config)
+            .map_err(|e| PixstripError::Config(e.to_string()))?;
+        std::fs::write(&self.config_path, json).map_err(PixstripError::Io)
+    }
+
+    pub fn load(&self) -> Result<AppConfig> {
+        if !self.config_path.exists() {
+            return Ok(AppConfig::default());
+        }
+        let data = std::fs::read_to_string(&self.config_path).map_err(PixstripError::Io)?;
+        serde_json::from_str(&data).map_err(|e| PixstripError::Config(e.to_string()))
+    }
+}
+
+impl Default for ConfigStore {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+// --- Session Store ---
+
+#[derive(Debug, Clone, Default, Serialize, Deserialize)]
+pub struct SessionState {
+    pub last_input_dir: Option<String>,
+    pub last_output_dir: Option<String>,
+    pub last_preset_name: Option<String>,
+    pub current_step: u32,
+}
+
+pub struct SessionStore {
+    session_path: PathBuf,
+}
+
+impl SessionStore {
+    pub fn new() -> Self {
+        Self {
+            session_path: default_config_dir().join("session.json"),
+        }
+    }
+
+    pub fn with_base_dir(base: &Path) -> Self {
+        Self {
+            session_path: base.join("session.json"),
+        }
+    }
+
+    pub fn save(&self, state: &SessionState) -> Result<()> {
+        if let Some(parent) = self.session_path.parent() {
+            std::fs::create_dir_all(parent).map_err(PixstripError::Io)?;
+        }
+        let json = serde_json::to_string_pretty(state)
+            .map_err(|e| PixstripError::Config(e.to_string()))?;
+        std::fs::write(&self.session_path, json).map_err(PixstripError::Io)
+    }
+
+    pub fn load(&self) -> Result<SessionState> {
+        if !self.session_path.exists() {
+            return Ok(SessionState::default());
+        }
+        let data = std::fs::read_to_string(&self.session_path).map_err(PixstripError::Io)?;
+        serde_json::from_str(&data).map_err(|e| PixstripError::Config(e.to_string()))
+    }
+}
+
+impl Default for SessionStore {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+// --- History Store ---
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct HistoryEntry {
+    pub timestamp: String,
+    pub input_dir: String,
+    pub output_dir: String,
+    pub preset_name: Option<String>,
+    pub total: usize,
+    pub succeeded: usize,
+    pub failed: usize,
+    pub total_input_bytes: u64,
+    pub total_output_bytes: u64,
+    pub elapsed_ms: u64,
+    pub output_files: Vec<String>,
+}
+
+pub struct HistoryStore {
+    history_path: PathBuf,
+}
+
+impl HistoryStore {
+    pub fn new() -> Self {
+        Self {
+            history_path: default_config_dir().join("history.json"),
+        }
+    }
+
+    pub fn with_base_dir(base: &Path) -> Self {
+        Self {
+            history_path: base.join("history.json"),
+        }
+    }
+
+    pub fn add(&self, entry: HistoryEntry) -> Result<()> {
+        let mut entries = self.list()?;
+        entries.push(entry);
+        self.write_all(&entries)
+    }
+
+    pub fn list(&self) -> Result<Vec<HistoryEntry>> {
+        if !self.history_path.exists() {
+            return Ok(Vec::new());
+        }
+        let data = std::fs::read_to_string(&self.history_path).map_err(PixstripError::Io)?;
+        if data.trim().is_empty() {
+            return Ok(Vec::new());
+        }
+        serde_json::from_str(&data).map_err(|e| PixstripError::Config(e.to_string()))
+    }
+
+    pub fn clear(&self) -> Result<()> {
+        self.write_all(&Vec::<HistoryEntry>::new())
+    }
+
+    fn write_all(&self, entries: &[HistoryEntry]) -> Result<()> {
+        if let Some(parent) = self.history_path.parent() {
+            std::fs::create_dir_all(parent).map_err(PixstripError::Io)?;
+        }
+        let json = serde_json::to_string_pretty(entries)
+            .map_err(|e| PixstripError::Config(e.to_string()))?;
+        std::fs::write(&self.history_path, json).map_err(PixstripError::Io)
+    }
+}
+
+impl Default for HistoryStore {
+    fn default() -> Self {
+        Self::new()
+    }
+}
diff --git a/pixstrip-core/tests/config_tests.rs b/pixstrip-core/tests/config_tests.rs
index ea3c207..2364d56 100644
--- a/pixstrip-core/tests/config_tests.rs
+++ b/pixstrip-core/tests/config_tests.rs
@@ -22,6 +22,6 @@ fn config_serialization_roundtrip() {
 
 #[test]
 fn skill_level_toggle() {
-    assert_eq!(SkillLevel::Simple.is_advanced(), false);
-    assert_eq!(SkillLevel::Detailed.is_advanced(), true);
+    assert!(!SkillLevel::Simple.is_advanced());
+    assert!(SkillLevel::Detailed.is_advanced());
 }
diff --git a/pixstrip-core/tests/storage_tests.rs b/pixstrip-core/tests/storage_tests.rs
new file mode 100644
index 0000000..7bdaf05
--- /dev/null
+++ b/pixstrip-core/tests/storage_tests.rs
@@ -0,0 +1,278 @@
+use pixstrip_core::preset::Preset;
+use pixstrip_core::storage::*;
+
+fn with_temp_config_dir(f: impl FnOnce(&std::path::Path)) {
+    let dir = tempfile::tempdir().unwrap();
+    f(dir.path());
+}
+
+// --- Preset file I/O ---
+
+#[test]
+fn save_and_load_preset() {
+    with_temp_config_dir(|base| {
+        let store = PresetStore::with_base_dir(base);
+        let preset = Preset::builtin_blog_photos();
+
+        store.save(&preset).unwrap();
+        let loaded = store.load("Blog Photos").unwrap();
+
+        assert_eq!(loaded.name, preset.name);
+        assert_eq!(loaded.is_custom, preset.is_custom);
+    });
+}
+
+#[test]
+fn save_preset_creates_directory() {
+    with_temp_config_dir(|base| {
+        let presets_dir = base.join("presets");
+        assert!(!presets_dir.exists());
+
+        let store = PresetStore::with_base_dir(base);
+        let preset = Preset::builtin_blog_photos();
+        store.save(&preset).unwrap();
+
+        assert!(presets_dir.exists());
+    });
+}
+
+#[test]
+fn list_saved_presets() {
+    with_temp_config_dir(|base| {
+        let store = PresetStore::with_base_dir(base);
+        store.save(&Preset::builtin_blog_photos()).unwrap();
+        store.save(&Preset::builtin_privacy_clean()).unwrap();
+
+        let list = store.list().unwrap();
+        assert_eq!(list.len(), 2);
+
+        let names: Vec<&str> = list.iter().map(|p| p.name.as_str()).collect();
+        assert!(names.contains(&"Blog Photos"));
+        assert!(names.contains(&"Privacy Clean"));
+    });
+}
+
+#[test]
+fn delete_preset() {
+    with_temp_config_dir(|base| {
+        let store = PresetStore::with_base_dir(base);
+        store.save(&Preset::builtin_blog_photos()).unwrap();
+
+        assert!(store.delete("Blog Photos").is_ok());
+        assert!(store.load("Blog Photos").is_err());
+    });
+}
+
+#[test]
+fn load_nonexistent_preset_returns_error() {
+    with_temp_config_dir(|base| {
+        let store = PresetStore::with_base_dir(base);
+        assert!(store.load("Nonexistent").is_err());
+    });
+}
+
+#[test]
+fn preset_filename_sanitization() {
+    with_temp_config_dir(|base| {
+        let store = PresetStore::with_base_dir(base);
+        let mut preset = Preset::builtin_blog_photos();
+        preset.name = "My Preset / With <Special> Chars!".into();
+        preset.is_custom = true;
+
+        store.save(&preset).unwrap();
+        let loaded = store.load("My Preset / With <Special> Chars!").unwrap();
+        assert_eq!(loaded.name, preset.name);
+    });
+}
+
+// --- Preset import/export ---
+
+#[test]
+fn export_and_import_preset() {
+    with_temp_config_dir(|base| {
+        let store = PresetStore::with_base_dir(base);
+        let preset = Preset::builtin_blog_photos();
+
+        let export_path = base.join("exported.pixstrip-preset");
+        store.export_to_file(&preset, &export_path).unwrap();
+
+        assert!(export_path.exists());
+
+        let imported = store.import_from_file(&export_path).unwrap();
+        assert_eq!(imported.name, preset.name);
+        assert!(imported.is_custom);
+    });
+}
+
+#[test]
+fn import_preset_marks_as_custom() {
+    with_temp_config_dir(|base| {
+        let store = PresetStore::with_base_dir(base);
+        let preset = Preset::builtin_blog_photos();
+
+        let export_path = base.join("test.pixstrip-preset");
+        store.export_to_file(&preset, &export_path).unwrap();
+
+        let imported = store.import_from_file(&export_path).unwrap();
+        assert!(imported.is_custom);
+    });
+}
+
+// --- Config persistence ---
+
+#[test]
+fn save_and_load_config() {
+    with_temp_config_dir(|base| {
+        let config_store = ConfigStore::with_base_dir(base);
+        let config = pixstrip_core::config::AppConfig {
+            output_subfolder: "output_images".into(),
+            auto_open_output: true,
+            ..Default::default()
+        };
+
+        config_store.save(&config).unwrap();
+        let loaded = config_store.load().unwrap();
+
+        assert_eq!(loaded.output_subfolder, "output_images");
+        assert!(loaded.auto_open_output);
+    });
+}
+
+#[test]
+fn load_missing_config_returns_default() {
+    with_temp_config_dir(|base| {
+        let config_store = ConfigStore::with_base_dir(base);
+        let config = config_store.load().unwrap();
+        let default = pixstrip_core::config::AppConfig::default();
+
+        assert_eq!(config.output_subfolder, default.output_subfolder);
+    });
+}
+
+// --- Session memory ---
+
+#[test]
+fn save_and_load_session() {
+    with_temp_config_dir(|base| {
+        let session_store = SessionStore::with_base_dir(base);
+        let session = SessionState {
+            last_input_dir: Some("/home/user/photos".into()),
+            last_output_dir: Some("/home/user/processed".into()),
+            last_preset_name: Some("Blog Photos".into()),
+            current_step: 3,
+        };
+
+        session_store.save(&session).unwrap();
+        let loaded = session_store.load().unwrap();
+
+        assert_eq!(loaded.last_input_dir.as_deref(), Some("/home/user/photos"));
+        assert_eq!(loaded.current_step, 3);
+    });
+}
+
+#[test]
+fn load_missing_session_returns_default() {
+    with_temp_config_dir(|base| {
+        let session_store = SessionStore::with_base_dir(base);
+        let session = session_store.load().unwrap();
+        assert_eq!(session.current_step, 0);
+        assert!(session.last_input_dir.is_none());
+    });
+}
+
+// --- Processing history ---
+
+#[test]
+fn add_and_list_history_entries() {
+    with_temp_config_dir(|base| {
+        let history = HistoryStore::with_base_dir(base);
+
+        let entry = HistoryEntry {
+            timestamp: "2026-03-06T12:00:00Z".into(),
+            input_dir: "/home/user/photos".into(),
+            output_dir: "/home/user/processed".into(),
+            preset_name: Some("Blog Photos".into()),
+            total: 10,
+            succeeded: 9,
+            failed: 1,
+            total_input_bytes: 50_000_000,
+            total_output_bytes: 10_000_000,
+            elapsed_ms: 5000,
+            output_files: vec![
+                "/home/user/processed/photo1.jpg".into(),
+                "/home/user/processed/photo2.jpg".into(),
+            ],
+        };
+
+        history.add(entry.clone()).unwrap();
+        let entries = history.list().unwrap();
+
+        assert_eq!(entries.len(), 1);
+        assert_eq!(entries[0].total, 10);
+        assert_eq!(entries[0].succeeded, 9);
+    });
+}
+
+#[test]
+fn history_appends_entries() {
+    with_temp_config_dir(|base| {
+        let history = HistoryStore::with_base_dir(base);
+
+        for i in 0..3 {
+            history
+                .add(HistoryEntry {
+                    timestamp: format!("2026-03-06T12:0{}:00Z", i),
+                    input_dir: "/input".into(),
+                    output_dir: "/output".into(),
+                    preset_name: None,
+                    total: i + 1,
+                    succeeded: i + 1,
+                    failed: 0,
+                    total_input_bytes: 1000,
+                    total_output_bytes: 500,
+                    elapsed_ms: 100,
+                    output_files: vec![],
+                })
+                .unwrap();
+        }
+
+        let entries = history.list().unwrap();
+        assert_eq!(entries.len(), 3);
+    });
+}
+
+#[test]
+fn clear_history() {
+    with_temp_config_dir(|base| {
+        let history = HistoryStore::with_base_dir(base);
+
+        history
+            .add(HistoryEntry {
+                timestamp: "2026-03-06T12:00:00Z".into(),
+                input_dir: "/input".into(),
+                output_dir: "/output".into(),
+                preset_name: None,
+                total: 1,
+                succeeded: 1,
+                failed: 0,
+                total_input_bytes: 1000,
+                total_output_bytes: 500,
+                elapsed_ms: 100,
+                output_files: vec![],
+            })
+            .unwrap();
+
+        history.clear().unwrap();
+        let entries = history.list().unwrap();
+        assert!(entries.is_empty());
+    });
+}
+
+#[test]
+fn empty_history_returns_empty_list() {
+    with_temp_config_dir(|base| {
+        let history = HistoryStore::with_base_dir(base);
+        let entries = history.list().unwrap();
+        assert!(entries.is_empty());
+    });
+}