diff --git a/README.md b/README.md
index 86ce382..5d6d4c5 100644
--- a/README.md
+++ b/README.md
@@ -26,5 +26,12 @@ If Go is installed but not available in `PATH`, use the full path:
 
 - `cmd/pysentry` starts the desktop app.
 - `internal/app` contains the first Fyne-based interface prototype.
-- Jobs can be created, edited, paused/resumed, and run manually in memory.
-- Job persistence, cron parsing, and process execution are planned for the next phase.
+- `internal/core` contains YAML storage, command execution, and the first scheduler loop.
+- Jobs can be created, edited, paused/resumed, run manually, and persisted to YAML.
+- Settings are stored in `pysentry.yaml` next to the executable.
+- Jobs are stored in one `jobs.yaml` file. The job directory is configured by `jobs_dir` and defaults to the executable directory.
+- Command output is also written to per-run `.log` files in `logs_dir`. Log filenames include the run timestamp and job name.
+- Log cleanup is controlled by `max_log_files` and `max_log_age_days`.
+- The current scheduler supports `@every` schedules such as `@every 10s` and `@every 1m`.
+- Run history records include a `trigger` value such as `Manual`, `Schedule`, or `UI`.
+- Cron expression parsing is planned for the next phase.
diff --git a/assets/pysentry-icon.png b/assets/pysentry-icon.png
new file mode 100644
index 0000000..1ce55cb
Binary files /dev/null and b/assets/pysentry-icon.png differ
diff --git a/go.mod b/go.mod
index 43ca880..9faa01f 100644
--- a/go.mod
+++ b/go.mod
@@ -2,7 +2,10 @@ module github.com/pysentry/pysentry
 
 go 1.22
 
-require fyne.io/fyne/v2 v2.5.3
+require (
+	fyne.io/fyne/v2 v2.5.3
+	gopkg.in/yaml.v3 v3.0.1
+)
 
 require (
 	fyne.io/systray v1.11.0 // indirect
@@ -33,5 +36,4 @@ require (
 	golang.org/x/net v0.25.0 // indirect
 	golang.org/x/sys v0.20.0 // indirect
 	golang.org/x/text v0.16.0 // indirect
-	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
diff --git a/internal/app/app.go b/internal/app/app.go
index 5b40d38..d1ede49 100644
--- a/internal/app/app.go
+++ b/internal/app/app.go
@@ -2,9 +2,14 @@ package app
 
 import (
 	"fmt"
+	"os"
+	"path/filepath"
+	"strconv"
 	"strings"
 	"time"
 
+	"github.com/pysentry/pysentry/internal/core"
+
 	"fyne.io/fyne/v2"
 	"fyne.io/fyne/v2/app"
 	"fyne.io/fyne/v2/container"
@@ -19,31 +24,12 @@ const appID = "io.github.pysentry.desktop"
 const allFolders = "All"
 const noFolder = "No folder"
 
-type job struct {
-	ID        int
-	Name      string
-	Folder    string
-	Schedule  string
-	Command   string
-	Enabled   bool
-	LastRun   string
-	NextRun   string
-	LastState string
-	Logs      []event
-	Output    string
-}
-
-type event struct {
-	Time    string
-	JobID   int
-	JobName string
-	State   string
-	Detail  string
-}
+type job = core.Job
+type event = core.RunRecord
 
 func Run() {
 	a := app.NewWithID(appID)
-	a.SetIcon(theme.ComputerIcon())
+	a.SetIcon(loadAppIcon())
 
 	w := a.NewWindow("PySentry")
 	configureSystemTray(a, w)
@@ -52,6 +38,22 @@ func Run() {
 	w.ShowAndRun()
 }
 
+func loadAppIcon() fyne.Resource {
+	candidates := []string{}
+	if executable, err := os.Executable(); err == nil {
+		candidates = append(candidates, filepath.Join(filepath.Dir(executable), "assets", "pysentry-icon.png"))
+	}
+	if workingDir, err := os.Getwd(); err == nil {
+		candidates = append(candidates, filepath.Join(workingDir, "assets", "pysentry-icon.png"))
+	}
+	for _, path := range candidates {
+		if resource, err := fyne.LoadResourceFromPath(path); err == nil {
+			return resource
+		}
+	}
+	return theme.ComputerIcon()
+}
+
 func configureSystemTray(a fyne.App, w fyne.Window) {
 	desk, ok := a.(desktop.App)
 	if !ok {
@@ -75,62 +77,13 @@ func configureSystemTray(a fyne.App, w fyne.Window) {
 }
 
 func newMainView(w fyne.Window) fyne.CanvasObject {
-	jobs := []job{
-		{
-			ID:        1,
-			Name:      "Nightly backup",
-			Folder:    "Maintenance",
-			Schedule:  "0 2 * * *",
-			Command:   "python scripts/backup.py",
-			Enabled:   true,
-			LastRun:   "Today 02:00",
-			NextRun:   "Tomorrow 02:00",
-			LastState: "OK",
-			Output:    "stdout: backup archive created\nstderr: <empty>",
-			Logs: []event{
-				{Time: "Today 02:00", JobID: 1, JobName: "Nightly backup", State: "OK", Detail: "Completed in 42 s"},
-				{Time: "Yesterday 02:00", JobID: 1, JobName: "Nightly backup", State: "OK", Detail: "Completed in 39 s"},
-			},
-		},
-		{
-			ID:        2,
-			Name:      "Health check",
-			Folder:    "Monitoring",
-			Schedule:  "*/15 * * * *",
-			Command:   "curl -fsS https://example.test/health",
-			Enabled:   true,
-			LastRun:   "21:00",
-			NextRun:   "21:15",
-			LastState: "OK",
-			Output:    "stdout: HTTP 200 OK\nstderr: <empty>",
-			Logs: []event{
-				{Time: "21:00", JobID: 2, JobName: "Health check", State: "OK", Detail: "Completed in 184 ms"},
-				{Time: "20:45", JobID: 2, JobName: "Health check", State: "OK", Detail: "Completed in 201 ms"},
-			},
-		},
-		{
-			ID:        3,
-			Name:      "Rotate logs",
-			Schedule:  "30 1 * * 1",
-			Command:   "pysentry rotate-logs",
-			Enabled:   false,
-			LastRun:   "Monday 01:30",
-			NextRun:   "Paused",
-			LastState: "Paused",
-			Output:    "No command output captured yet.",
-			Logs: []event{
-				{Time: "Yesterday 01:30", JobID: 3, JobName: "Rotate logs", State: "Paused", Detail: "Skipped because the job is paused"},
-			},
-		},
-	}
-	events := []event{
-		{Time: "21:00", JobID: 2, JobName: "Health check", State: "OK", Detail: "Completed in 184 ms"},
-		{Time: "20:45", JobID: 2, JobName: "Health check", State: "OK", Detail: "Completed in 201 ms"},
-		{Time: "02:00", JobID: 1, JobName: "Nightly backup", State: "OK", Detail: "Completed in 42 s"},
-		{Time: "Yesterday 01:30", JobID: 3, JobName: "Rotate logs", State: "Paused", Detail: "Skipped because the job is paused"},
+	store, jobs, err := core.OpenStore()
+	if err != nil {
+		return container.NewPadded(widget.NewLabel("Failed to load PySentry configuration: " + err.Error()))
 	}
+	events := collectActivity(jobs)
 
-	nextJobID := 4
+	nextJobID := nextID(jobs)
 	selected := 0
 	selectedFolder := allFolders
 	schedulerPaused := false
@@ -143,9 +96,10 @@ func newMainView(w fyne.Window) fyne.CanvasObject {
 	nextRun := widget.NewLabel(jobs[selected].NextRun)
 	state := widget.NewLabel(jobs[selected].LastState)
 	schedulerState := widget.NewLabel("Scheduler running")
-	commandOutput := widget.NewMultiLineEntry()
+	commandOutput := widget.NewTextGrid()
 	commandOutput.SetText(jobs[selected].Output)
-	commandOutput.Disable()
+	commandOutputScroll := container.NewScroll(commandOutput)
+	commandOutputScroll.SetMinSize(fyne.NewSize(520, 160))
 	history := newHistoryView(&events)
 	jobLogs := widget.NewList(
 		func() int {
@@ -189,6 +143,7 @@ func newMainView(w fyne.Window) fyne.CanvasObject {
 		jobLogs.Refresh()
 		history.Refresh()
 	}
+	var scheduler *core.Scheduler
 
 	list := widget.NewList(
 		func() int { return len(filteredJobs) },
@@ -238,7 +193,7 @@ func newMainView(w fyne.Window) fyne.CanvasObject {
 	folderSelect.SetSelected(selectedFolder)
 
 	addButton := widget.NewButtonWithIcon("New job", theme.ContentAddIcon(), func() {
-		showJobDialog(w, "New job", job{Enabled: true, LastRun: "Never", NextRun: "After save", LastState: "Ready"}, func(saved job) {
+		showJobDialog(w, "New job", job{Schedule: "@every 1m", Command: "echo PySentry job ran", Enabled: true, LastRun: "Never", NextRun: "After save", LastState: "Ready"}, func(saved job) {
 			saved.ID = nextJobID
 			nextJobID++
 			jobs = append(jobs, saved)
@@ -246,6 +201,7 @@ func newMainView(w fyne.Window) fyne.CanvasObject {
 			created := newEvent(saved.ID, saved.Name, "Created", "Job was added")
 			jobs[selected].Logs = append([]event{created}, jobs[selected].Logs...)
 			events = append([]event{created}, events...)
+			_ = store.SaveJobs(jobs)
 			folderSelect.Options = folderOptions(jobs)
 			folderSelect.Refresh()
 			targetFolder := filterValue(saved.Folder)
@@ -271,6 +227,10 @@ func newMainView(w fyne.Window) fyne.CanvasObject {
 			updated := newEvent(saved.ID, saved.Name, "Updated", "Job settings changed")
 			jobs[selected].Logs = append([]event{updated}, jobs[selected].Logs...)
 			events = append([]event{updated}, events...)
+			if scheduler != nil {
+				scheduler.RefreshSchedule(selected)
+			}
+			_ = store.SaveJobs(jobs)
 			folderSelect.Options = folderOptions(jobs)
 			folderSelect.Refresh()
 			list.Refresh()
@@ -285,14 +245,10 @@ func newMainView(w fyne.Window) fyne.CanvasObject {
 			dialog.ShowInformation("Scheduler paused", "Global pause is active. Resume the scheduler before running jobs.", w)
 			return
 		}
-		jobs[selected].LastRun = "Just now"
-		jobs[selected].LastState = "OK"
-		jobs[selected].Output = "stdout: manual run simulated\nstderr: <empty>"
-		if jobs[selected].Enabled {
-			jobs[selected].NextRun = "Waiting for scheduler"
+		ran := scheduler.RunNow(selected)
+		if ran.Time == "" {
+			return
 		}
-		ran := newEvent(jobs[selected].ID, jobs[selected].Name, "OK", "Manual run simulated")
-		jobs[selected].Logs = append([]event{ran}, jobs[selected].Logs...)
 		events = append([]event{ran}, events...)
 		list.Refresh()
 		refresh()
@@ -309,6 +265,9 @@ func newMainView(w fyne.Window) fyne.CanvasObject {
 					jobs[index].NextRun = "Scheduler paused"
 				}
 			}
+			if scheduler != nil {
+				scheduler.SetPaused(true)
+			}
 			events = append([]event{newEvent(0, "Scheduler", "Paused", "All job execution paused")}, events...)
 		} else {
 			schedulerState.SetText("Scheduler running")
@@ -319,6 +278,9 @@ func newMainView(w fyne.Window) fyne.CanvasObject {
 					jobs[index].NextRun = "Waiting for scheduler"
 				}
 			}
+			if scheduler != nil {
+				scheduler.SetPaused(false)
+			}
 			events = append([]event{newEvent(0, "Scheduler", "Resumed", "All job execution resumed")}, events...)
 		}
 		list.Refresh()
@@ -336,13 +298,20 @@ func newMainView(w fyne.Window) fyne.CanvasObject {
 			resumed := newEvent(current.ID, current.Name, "Resumed", "Job was enabled")
 			current.Logs = append([]event{resumed}, current.Logs...)
 			events = append([]event{resumed}, events...)
+			if scheduler != nil {
+				scheduler.RefreshSchedule(selected)
+			}
 		} else {
 			current.LastState = "Paused"
 			current.NextRun = "Paused"
 			paused := newEvent(current.ID, current.Name, "Paused", "Job was disabled")
 			current.Logs = append([]event{paused}, current.Logs...)
 			events = append([]event{paused}, events...)
+			if scheduler != nil {
+				scheduler.RefreshSchedule(selected)
+			}
 		}
+		_ = store.SaveJobs(jobs)
 		list.Refresh()
 		refresh()
 	})
@@ -370,6 +339,7 @@ func newMainView(w fyne.Window) fyne.CanvasObject {
 				selected = filteredJobs[0]
 			}
 			events = append([]event{newEvent(deleted.ID, deleted.Name, "Deleted", "Job was removed")}, events...)
+			_ = store.SaveJobs(jobs)
 			list.Refresh()
 			if selected >= 0 {
 				list.Select(displayIndex(filteredJobs, selected))
@@ -394,16 +364,22 @@ func newMainView(w fyne.Window) fyne.CanvasObject {
 		detailRow("State", state),
 		widget.NewSeparator(),
 		widget.NewLabelWithStyle("Command output", fyne.TextAlignLeading, fyne.TextStyle{Bold: true}),
-		commandOutput,
+		commandOutputScroll,
 		widget.NewSeparator(),
 		widget.NewLabelWithStyle("Selected job activity", fyne.TextAlignLeading, fyne.TextStyle{Bold: true}),
 		jobLogs,
 	)
 
+	scheduler = core.NewScheduler(store, &jobs, func(record core.RunRecord) {
+		events = append([]event{record}, events...)
+		refresh()
+	})
+	scheduler.Start()
+
 	tabs := container.NewAppTabs(
 		container.NewTabItemWithIcon("Jobs", theme.ListIcon(), container.NewHSplit(sidebar, container.NewPadded(details))),
 		container.NewTabItemWithIcon("History", theme.HistoryIcon(), history),
-		container.NewTabItemWithIcon("Settings", theme.SettingsIcon(), settingsView()),
+		container.NewTabItemWithIcon("Settings", theme.SettingsIcon(), settingsView(store)),
 	)
 	tabs.SetTabLocation(container.TabLocationTop)
 
@@ -422,13 +398,39 @@ func newEvent(jobID int, jobName string, state string, detail string) event {
 		Time:    time.Now().Format("15:04:05"),
 		JobID:   jobID,
 		JobName: jobName,
+		Trigger: "UI",
 		State:   state,
 		Detail:  detail,
 	}
 }
 
 func eventText(e event) string {
-	return fmt.Sprintf("%s  %s  %s  %s", e.Time, e.JobName, e.State, e.Detail)
+	trigger := e.Trigger
+	if trigger == "" {
+		trigger = "Unknown"
+	}
+	if e.LogFile != "" {
+		return fmt.Sprintf("%s  %s  %s  %s  %s  %s", e.Time, trigger, e.JobName, e.State, e.Detail, e.LogFile)
+	}
+	return fmt.Sprintf("%s  %s  %s  %s  %s", e.Time, trigger, e.JobName, e.State, e.Detail)
+}
+
+func collectActivity(jobs []job) []event {
+	var events []event
+	for _, current := range jobs {
+		events = append(events, current.Logs...)
+	}
+	return events
+}
+
+func nextID(jobs []job) int {
+	next := 1
+	for _, current := range jobs {
+		if current.ID >= next {
+			next = current.ID + 1
+		}
+	}
+	return next
 }
 
 func detailRow(label string, value fyne.CanvasObject) fyne.CanvasObject {
@@ -492,10 +494,10 @@ func showJobDialog(w fyne.Window, title string, current job, onSave func(job)) {
 	folder.SetPlaceHolder("Maintenance")
 	folder.SetText(current.Folder)
 	schedule := widget.NewEntry()
-	schedule.SetPlaceHolder("0 2 * * *")
+	schedule.SetPlaceHolder("@every 1m")
 	schedule.SetText(current.Schedule)
 	command := widget.NewEntry()
-	command.SetPlaceHolder("python scripts/backup.py")
+	command.SetPlaceHolder("echo PySentry job ran")
 	command.SetText(current.Command)
 	enabled := widget.NewCheck("Enabled", nil)
 	enabled.SetChecked(current.Enabled)
@@ -555,12 +557,46 @@ func newHistoryView(events *[]event) *fyne.Container {
 	return container.NewPadded(list)
 }
 
-func settingsView() fyne.CanvasObject {
+func settingsView(store *core.Store) fyne.CanvasObject {
 	runOnStartup := widget.NewCheck("Start PySentry when I sign in", nil)
 	minimizeToTray := widget.NewCheck("Keep running in the system tray", nil)
-	minimizeToTray.SetChecked(true)
+	minimizeToTray.SetChecked(store.Config.KeepRunningInTray)
 	notifications := widget.NewCheck("Show desktop notifications for failed jobs", nil)
-	notifications.SetChecked(true)
+	notifications.SetChecked(store.Config.NotifyOnFailure)
+	logsDir := widget.NewEntry()
+	logsDir.SetText(store.Config.LogsDir)
+	maxLogFiles := widget.NewEntry()
+	maxLogFiles.SetText(strconv.Itoa(store.Config.MaxLogFiles))
+	maxLogAgeDays := widget.NewEntry()
+	maxLogAgeDays.SetText(strconv.Itoa(store.Config.MaxLogAgeDays))
+	settingsStatus := widget.NewLabel("")
+
+	saveSettings := widget.NewButtonWithIcon("Save settings", theme.DocumentSaveIcon(), func() {
+		files, err := strconv.Atoi(strings.TrimSpace(maxLogFiles.Text))
+		if err != nil || files <= 0 {
+			settingsStatus.SetText("Max log files must be a positive number")
+			return
+		}
+		days, err := strconv.Atoi(strings.TrimSpace(maxLogAgeDays.Text))
+		if err != nil || days <= 0 {
+			settingsStatus.SetText("Max log age days must be a positive number")
+			return
+		}
+		store.Config.LogsDir = strings.TrimSpace(logsDir.Text)
+		store.Config.MaxLogFiles = files
+		store.Config.MaxLogAgeDays = days
+		store.Config.KeepRunningInTray = minimizeToTray.Checked
+		store.Config.NotifyOnFailure = notifications.Checked
+		if err := store.SaveConfig(); err != nil {
+			settingsStatus.SetText("Save failed: " + err.Error())
+			return
+		}
+		if err := core.CleanupLogs(store.Paths.LogsDir, store.Config.MaxLogFiles, store.Config.MaxLogAgeDays); err != nil {
+			settingsStatus.SetText("Saved, cleanup failed: " + err.Error())
+			return
+		}
+		settingsStatus.SetText("Saved")
+	})
 
 	return container.NewPadded(container.NewVBox(
 		widget.NewLabelWithStyle("Application", fyne.TextAlignLeading, fyne.TextStyle{Bold: true}),
@@ -568,7 +604,17 @@ func settingsView() fyne.CanvasObject {
 		minimizeToTray,
 		notifications,
 		widget.NewSeparator(),
+		widget.NewLabelWithStyle("Storage", fyne.TextAlignLeading, fyne.TextStyle{Bold: true}),
+		detailRow("Config YAML", widget.NewLabel(store.Paths.ConfigPath)),
+		detailRow("Jobs YAML", widget.NewLabel(store.Paths.JobsPath)),
+		detailRow("Jobs directory", widget.NewLabel(store.Paths.JobsDir)),
+		detailRow("Logs directory", logsDir),
+		detailRow("Max log files", maxLogFiles),
+		detailRow("Max log age days", maxLogAgeDays),
+		saveSettings,
+		settingsStatus,
+		widget.NewSeparator(),
 		widget.NewLabelWithStyle("Scheduler", fyne.TextAlignLeading, fyne.TextStyle{Bold: true}),
-		widget.NewLabel("The scheduler service, job storage, and cron parser come next."),
+		widget.NewLabel("Current core supports @every schedules. Cron expressions come next."),
 	))
 }
diff --git a/internal/core/model.go b/internal/core/model.go
new file mode 100644
index 0000000..e3eeb6f
--- /dev/null
+++ b/internal/core/model.go
@@ -0,0 +1,43 @@
+package core
+
+import "time"
+
+type Config struct {
+	JobsDir           string `yaml:"jobs_dir"`
+	LogsDir           string `yaml:"logs_dir"`
+	MaxLogFiles       int    `yaml:"max_log_files"`
+	MaxLogAgeDays     int    `yaml:"max_log_age_days"`
+	KeepRunningInTray bool   `yaml:"keep_running_in_tray"`
+	NotifyOnFailure   bool   `yaml:"notify_on_failure"`
+}
+
+type JobsFile struct {
+	Jobs []Job `yaml:"jobs"`
+}
+
+type Job struct {
+	ID        int         `yaml:"id"`
+	Name      string      `yaml:"name"`
+	Folder    string      `yaml:"folder,omitempty"`
+	Schedule  string      `yaml:"schedule"`
+	Command   string      `yaml:"command"`
+	Enabled   bool        `yaml:"enabled"`
+	LastRun   string      `yaml:"last_run,omitempty"`
+	NextRun   string      `yaml:"next_run,omitempty"`
+	LastState string      `yaml:"last_state,omitempty"`
+	Logs      []RunRecord `yaml:"activity,omitempty"`
+	Output    string      `yaml:"last_output,omitempty"`
+
+	nextDue time.Time
+}
+
+type RunRecord struct {
+	Time    string `yaml:"time"`
+	JobID   int    `yaml:"job_id"`
+	JobName string `yaml:"job_name"`
+	Trigger string `yaml:"trigger,omitempty"`
+	State   string `yaml:"state"`
+	Detail  string `yaml:"detail"`
+	LogFile string `yaml:"log_file,omitempty"`
+	Output  string `yaml:"output,omitempty"`
+}
diff --git a/internal/core/paths.go b/internal/core/paths.go
new file mode 100644
index 0000000..3450010
--- /dev/null
+++ b/internal/core/paths.go
@@ -0,0 +1,35 @@
+package core
+
+import (
+	"os"
+	"path/filepath"
+)
+
+const (
+	ConfigFileName = "pysentry.yaml"
+	JobsFileName   = "jobs.yaml"
+)
+
+type Paths struct {
+	AppDir     string
+	ConfigPath string
+	JobsDir    string
+	JobsPath   string
+	LogsDir    string
+}
+
+func ResolvePaths() (Paths, error) {
+	executable, err := os.Executable()
+	if err != nil {
+		return Paths{}, err
+	}
+
+	appDir := filepath.Dir(executable)
+	configPath := filepath.Join(appDir, ConfigFileName)
+	return Paths{
+		AppDir:     appDir,
+		ConfigPath: configPath,
+		JobsDir:    appDir,
+		JobsPath:   filepath.Join(appDir, JobsFileName),
+	}, nil
+}
diff --git a/internal/core/runner.go b/internal/core/runner.go
new file mode 100644
index 0000000..3e7f0be
--- /dev/null
+++ b/internal/core/runner.go
@@ -0,0 +1,169 @@
+package core
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"sort"
+	"strings"
+	"time"
+	"unicode"
+)
+
+const commandTimeout = 30 * time.Second
+
+func RunJob(ctx context.Context, job *Job, trigger string, logsDir string) RunRecord {
+	started := time.Now()
+	runCtx, cancel := context.WithTimeout(ctx, commandTimeout)
+	defer cancel()
+
+	command := shellCommand(runCtx, job.Command)
+	var stdout bytes.Buffer
+	var stderr bytes.Buffer
+	command.Stdout = &stdout
+	command.Stderr = &stderr
+
+	err := command.Run()
+	duration := time.Since(started).Round(time.Millisecond)
+	output := formatOutput(stdout.String(), stderr.String())
+
+	state := "OK"
+	detail := fmt.Sprintf("Completed in %s", duration)
+	if err != nil {
+		state = "Failed"
+		if errors.Is(runCtx.Err(), context.DeadlineExceeded) {
+			detail = fmt.Sprintf("Timed out after %s", commandTimeout)
+		} else {
+			detail = err.Error()
+		}
+	}
+
+	now := time.Now()
+	job.LastRun = now.Format("2006-01-02 15:04:05")
+	job.LastState = state
+	job.Output = output
+	logFile := writeRunLog(logsDir, *job, trigger, state, detail, output, now)
+
+	record := RunRecord{
+		Time:    job.LastRun,
+		JobID:   job.ID,
+		JobName: job.Name,
+		Trigger: trigger,
+		State:   state,
+		Detail:  detail,
+		LogFile: logFile,
+		Output:  output,
+	}
+	job.Logs = append([]RunRecord{record}, job.Logs...)
+	if len(job.Logs) > 50 {
+		job.Logs = job.Logs[:50]
+	}
+	return record
+}
+
+func CleanupLogs(logsDir string, maxFiles int, maxAgeDays int) error {
+	entries, err := os.ReadDir(logsDir)
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			return nil
+		}
+		return err
+	}
+
+	type logFile struct {
+		path    string
+		modTime time.Time
+	}
+	var logs []logFile
+	cutoff := time.Now().AddDate(0, 0, -maxAgeDays)
+	for _, entry := range entries {
+		if entry.IsDir() || !strings.HasSuffix(strings.ToLower(entry.Name()), ".log") {
+			continue
+		}
+		path := filepath.Join(logsDir, entry.Name())
+		info, err := entry.Info()
+		if err != nil {
+			continue
+		}
+		if maxAgeDays > 0 && info.ModTime().Before(cutoff) {
+			_ = os.Remove(path)
+			continue
+		}
+		logs = append(logs, logFile{path: path, modTime: info.ModTime()})
+	}
+
+	if maxFiles <= 0 || len(logs) <= maxFiles {
+		return nil
+	}
+	sort.Slice(logs, func(i int, j int) bool {
+		return logs[i].modTime.After(logs[j].modTime)
+	})
+	for _, old := range logs[maxFiles:] {
+		_ = os.Remove(old.path)
+	}
+	return nil
+}
+
+func writeRunLog(logsDir string, job Job, trigger string, state string, detail string, output string, started time.Time) string {
+	if strings.TrimSpace(logsDir) == "" {
+		return ""
+	}
+	if err := os.MkdirAll(logsDir, 0o755); err != nil {
+		return ""
+	}
+	fileName := started.Format("20060102-150405") + "_" + sanitizeFileName(job.Name) + ".log"
+	path := filepath.Join(logsDir, fileName)
+	content := fmt.Sprintf("time: %s\njob_id: %d\njob_name: %s\ntrigger: %s\nstate: %s\ndetail: %s\ncommand: %s\n\n%s\n",
+		started.Format("2006-01-02 15:04:05"), job.ID, job.Name, trigger, state, detail, job.Command, output)
+	if err := os.WriteFile(path, []byte(content), 0o644); err != nil {
+		return ""
+	}
+	return path
+}
+
+func sanitizeFileName(name string) string {
+	name = strings.TrimSpace(name)
+	if name == "" {
+		return "job"
+	}
+	var builder strings.Builder
+	for _, r := range name {
+		switch {
+		case unicode.IsLetter(r), unicode.IsDigit(r):
+			builder.WriteRune(r)
+		case r == '-', r == '_':
+			builder.WriteRune(r)
+		default:
+			builder.WriteRune('_')
+		}
+	}
+	result := strings.Trim(builder.String(), "_")
+	if result == "" {
+		return "job"
+	}
+	return result
+}
+
+func shellCommand(ctx context.Context, command string) *exec.Cmd {
+	if runtime.GOOS == "windows" {
+		return exec.CommandContext(ctx, "cmd.exe", "/C", command)
+	}
+	return exec.CommandContext(ctx, "sh", "-c", command)
+}
+
+func formatOutput(stdout string, stderr string) string {
+	stdout = strings.TrimSpace(stdout)
+	stderr = strings.TrimSpace(stderr)
+	if stdout == "" {
+		stdout = "<empty>"
+	}
+	if stderr == "" {
+		stderr = "<empty>"
+	}
+	return "stdout:\n" + stdout + "\n\nstderr:\n" + stderr
+}
diff --git a/internal/core/runner_test.go b/internal/core/runner_test.go
new file mode 100644
index 0000000..671b328
--- /dev/null
+++ b/internal/core/runner_test.go
@@ -0,0 +1,40 @@
+package core
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestRunJobWritesLogFile(t *testing.T) {
+	logsDir := t.TempDir()
+	job := Job{
+		ID:      42,
+		Name:    "Hello Test",
+		Command: echoCommand("hello from test"),
+	}
+
+	record := RunJob(context.Background(), &job, "Manual", logsDir)
+	if record.LogFile == "" {
+		t.Fatal("expected log file path")
+	}
+	if filepath.Dir(record.LogFile) != logsDir {
+		t.Fatalf("expected log in %q, got %q", logsDir, record.LogFile)
+	}
+	if !strings.Contains(filepath.Base(record.LogFile), "Hello_Test") {
+		t.Fatalf("expected job name in log filename, got %q", record.LogFile)
+	}
+
+	data, err := os.ReadFile(record.LogFile)
+	if err != nil {
+		t.Fatal(err)
+	}
+	content := string(data)
+	for _, want := range []string{"trigger: Manual", "job_name: Hello Test", "hello from test"} {
+		if !strings.Contains(content, want) {
+			t.Fatalf("expected log content to contain %q, got:\n%s", want, content)
+		}
+	}
+}
diff --git a/internal/core/scheduler.go b/internal/core/scheduler.go
new file mode 100644
index 0000000..ea17692
--- /dev/null
+++ b/internal/core/scheduler.go
@@ -0,0 +1,169 @@
+package core
+
+import (
+	"context"
+	"strings"
+	"sync"
+	"time"
+)
+
+type Scheduler struct {
+	store    *Store
+	jobs     *[]Job
+	onChange func(RunRecord)
+
+	mu     sync.Mutex
+	ctx    context.Context
+	cancel context.CancelFunc
+	paused bool
+}
+
+func NewScheduler(store *Store, jobs *[]Job, onChange func(RunRecord)) *Scheduler {
+	ctx, cancel := context.WithCancel(context.Background())
+	s := &Scheduler{
+		store:    store,
+		jobs:     jobs,
+		onChange: onChange,
+		ctx:      ctx,
+		cancel:   cancel,
+	}
+	s.resetNextRuns(time.Now())
+	return s
+}
+
+func (s *Scheduler) Start() {
+	ticker := time.NewTicker(time.Second)
+	go func() {
+		defer ticker.Stop()
+		for {
+			select {
+			case <-s.ctx.Done():
+				return
+			case now := <-ticker.C:
+				s.tick(now)
+			}
+		}
+	}()
+}
+
+func (s *Scheduler) Stop() {
+	s.cancel()
+}
+
+func (s *Scheduler) SetPaused(paused bool) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	s.paused = paused
+	now := time.Now()
+	for index := range *s.jobs {
+		job := &(*s.jobs)[index]
+		if !job.Enabled {
+			job.NextRun = "Paused"
+			continue
+		}
+		if paused {
+			job.NextRun = "Scheduler paused"
+			continue
+		}
+		s.prepareNextRun(job, now)
+	}
+	_ = s.store.SaveJobs(*s.jobs)
+}
+
+func (s *Scheduler) RunNow(index int) RunRecord {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	if index < 0 || index >= len(*s.jobs) {
+		return RunRecord{}
+	}
+	job := &(*s.jobs)[index]
+	record := RunJob(s.ctx, job, "Manual", s.store.Paths.LogsDir)
+	s.prepareNextRun(job, time.Now())
+	_ = CleanupLogs(s.store.Paths.LogsDir, s.store.Config.MaxLogFiles, s.store.Config.MaxLogAgeDays)
+	_ = s.store.SaveJobs(*s.jobs)
+	return record
+}
+
+func (s *Scheduler) RefreshSchedule(index int) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	if index < 0 || index >= len(*s.jobs) {
+		return
+	}
+	job := &(*s.jobs)[index]
+	if !job.Enabled {
+		job.NextRun = "Paused"
+		return
+	}
+	if s.paused {
+		job.NextRun = "Scheduler paused"
+		return
+	}
+	s.prepareNextRun(job, time.Now())
+}
+
+func (s *Scheduler) tick(now time.Time) {
+	var record RunRecord
+	var changed bool
+
+	s.mu.Lock()
+	if !s.paused {
+		for index := range *s.jobs {
+			job := &(*s.jobs)[index]
+			if !job.Enabled || job.nextDue.IsZero() || now.Before(job.nextDue) {
+				continue
+			}
+			record = RunJob(s.ctx, job, "Schedule", s.store.Paths.LogsDir)
+			s.prepareNextRun(job, time.Now())
+			_ = CleanupLogs(s.store.Paths.LogsDir, s.store.Config.MaxLogFiles, s.store.Config.MaxLogAgeDays)
+			changed = true
+			break
+		}
+	}
+	if changed {
+		_ = s.store.SaveJobs(*s.jobs)
+	}
+	s.mu.Unlock()
+
+	if changed && s.onChange != nil {
+		s.onChange(record)
+	}
+}
+
+func (s *Scheduler) resetNextRuns(now time.Time) {
+	for index := range *s.jobs {
+		job := &(*s.jobs)[index]
+		if !job.Enabled {
+			job.NextRun = "Paused"
+			continue
+		}
+		s.prepareNextRun(job, now)
+	}
+	_ = s.store.SaveJobs(*s.jobs)
+}
+
+func (s *Scheduler) prepareNextRun(job *Job, from time.Time) {
+	interval, ok := parseEvery(job.Schedule)
+	if !ok {
+		job.NextRun = "Unsupported schedule"
+		job.nextDue = time.Time{}
+		return
+	}
+	job.nextDue = from.Add(interval)
+	job.NextRun = job.nextDue.Format("2006-01-02 15:04:05")
+}
+
+func parseEvery(schedule string) (time.Duration, bool) {
+	schedule = strings.TrimSpace(schedule)
+	if !strings.HasPrefix(schedule, "@every ") {
+		return 0, false
+	}
+	interval, err := time.ParseDuration(strings.TrimSpace(strings.TrimPrefix(schedule, "@every ")))
+	if err != nil || interval <= 0 {
+		return 0, false
+	}
+	return interval, true
+}
diff --git a/internal/core/store.go b/internal/core/store.go
new file mode 100644
index 0000000..20c2ec1
--- /dev/null
+++ b/internal/core/store.go
@@ -0,0 +1,183 @@
+package core
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+
+	"gopkg.in/yaml.v3"
+)
+
+type Store struct {
+	Paths  Paths
+	Config Config
+}
+
+func OpenStore() (*Store, []Job, error) {
+	paths, err := ResolvePaths()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	store := &Store{Paths: paths}
+	config, err := loadOrCreateConfig(paths)
+	if err != nil {
+		return nil, nil, err
+	}
+	store.Config = config
+	store.applyConfigPaths()
+	if err := store.SaveConfig(); err != nil {
+		return nil, nil, err
+	}
+
+	jobs, err := loadOrCreateJobs(store.Paths.JobsPath)
+	if err != nil {
+		return nil, nil, err
+	}
+	return store, jobs, nil
+}
+
+func (s *Store) SaveConfig() error {
+	s.applyConfigPaths()
+	if err := os.MkdirAll(s.Paths.AppDir, 0o755); err != nil {
+		return err
+	}
+	return writeYAML(s.Paths.ConfigPath, s.Config)
+}
+
+func (s *Store) SaveJobs(jobs []Job) error {
+	if err := os.MkdirAll(s.Paths.JobsDir, 0o755); err != nil {
+		return err
+	}
+	return writeYAML(s.Paths.JobsPath, JobsFile{Jobs: jobs})
+}
+
+func loadOrCreateConfig(paths Paths) (Config, error) {
+	config := Config{
+		JobsDir:           ".",
+		LogsDir:           "logs",
+		MaxLogFiles:       100,
+		MaxLogAgeDays:     30,
+		KeepRunningInTray: true,
+		NotifyOnFailure:   true,
+	}
+
+	if _, err := os.Stat(paths.ConfigPath); errors.Is(err, os.ErrNotExist) {
+		return config, writeYAML(paths.ConfigPath, config)
+	}
+
+	data, err := os.ReadFile(paths.ConfigPath)
+	if err != nil {
+		return Config{}, err
+	}
+	if err := yaml.Unmarshal(data, &config); err != nil {
+		return Config{}, err
+	}
+	if strings.TrimSpace(config.JobsDir) == "" {
+		config.JobsDir = "."
+	}
+	if strings.TrimSpace(config.LogsDir) == "" {
+		config.LogsDir = "logs"
+	}
+	if config.MaxLogFiles <= 0 {
+		config.MaxLogFiles = 100
+	}
+	if config.MaxLogAgeDays <= 0 {
+		config.MaxLogAgeDays = 30
+	}
+	return config, nil
+}
+
+func loadOrCreateJobs(path string) ([]Job, error) {
+	if _, err := os.Stat(path); errors.Is(err, os.ErrNotExist) {
+		jobs := defaultJobs()
+		return jobs, writeYAML(path, JobsFile{Jobs: jobs})
+	}
+
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	var file JobsFile
+	if err := yaml.Unmarshal(data, &file); err != nil {
+		return nil, err
+	}
+	return file.Jobs, nil
+}
+
+func resolveJobsDir(appDir string, jobsDir string) string {
+	return resolveConfiguredDir(appDir, jobsDir)
+}
+
+func resolveConfiguredDir(appDir string, dir string) string {
+	if filepath.IsAbs(dir) {
+		return dir
+	}
+	return filepath.Clean(filepath.Join(appDir, dir))
+}
+
+func (s *Store) applyConfigPaths() {
+	s.Paths.JobsDir = resolveConfiguredDir(s.Paths.AppDir, s.Config.JobsDir)
+	s.Paths.JobsPath = filepath.Join(s.Paths.JobsDir, JobsFileName)
+	s.Paths.LogsDir = resolveConfiguredDir(s.Paths.AppDir, s.Config.LogsDir)
+}
+
+func writeYAML(path string, value any) error {
+	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+		return err
+	}
+	data, err := yaml.Marshal(value)
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(path, data, 0o644)
+}
+
+func defaultJobs() []Job {
+	return []Job{
+		{
+			ID:        1,
+			Name:      "Hello scheduler",
+			Folder:    "Examples",
+			Schedule:  "@every 10s",
+			Command:   echoCommand("PySentry test job: scheduler is alive"),
+			Enabled:   true,
+			LastRun:   "Never",
+			NextRun:   "After start",
+			LastState: "Ready",
+			Output:    "No command output captured yet.",
+		},
+		{
+			ID:        2,
+			Name:      "Write timestamp",
+			Folder:    "Examples",
+			Schedule:  "@every 15s",
+			Command:   echoCommand("PySentry test job: timestamp command ran"),
+			Enabled:   true,
+			LastRun:   "Never",
+			NextRun:   "After start",
+			LastState: "Ready",
+			Output:    "No command output captured yet.",
+		},
+		{
+			ID:        3,
+			Name:      "Paused sample",
+			Schedule:  "@every 1m",
+			Command:   echoCommand("This paused sample should not run until enabled"),
+			Enabled:   false,
+			LastRun:   "Never",
+			NextRun:   "Paused",
+			LastState: "Paused",
+			Output:    "No command output captured yet.",
+		},
+	}
+}
+
+func echoCommand(message string) string {
+	if runtime.GOOS == "windows" {
+		return "echo " + message
+	}
+	return "echo '" + strings.ReplaceAll(message, "'", "'\\''") + "'"
+}