diff --git a/cmd/worker/main.go b/cmd/worker/main.go
index 2654f0b..adbf91b 100644
--- a/cmd/worker/main.go
+++ b/cmd/worker/main.go
@@ -20,7 +20,6 @@
 	"text/tabwriter"
 	"time"
 
-	"golang.org/x/exp/event"
 	"golang.org/x/vulndb/internal/cvelistrepo"
 	"golang.org/x/vulndb/internal/ghsa"
 	"golang.org/x/vulndb/internal/gitrepo"
@@ -88,8 +87,8 @@
 		dieWithUsage("%v", err)
 	}
 
-	ctx := event.WithExporter(context.Background(),
-		event.NewExporter(log.NewLineHandler(os.Stderr), nil))
+	ctx := context.Background()
+
 	if img := os.Getenv("DOCKER_IMAGE"); img != "" {
 		log.Infof(ctx, "running in docker image %s", img)
 	}
diff --git a/go.mod b/go.mod
index 6f2b609..d774f3e 100644
--- a/go.mod
+++ b/go.mod
@@ -25,8 +25,7 @@
 	go.opentelemetry.io/otel v1.21.0
 	go.opentelemetry.io/otel/sdk v1.21.0
 	go.opentelemetry.io/otel/trace v1.21.0
-	golang.org/x/exp v0.0.0-20231219180239-dc181d75b848
-	golang.org/x/exp/event v0.0.0-20231219180239-dc181d75b848
+	golang.org/x/exp v0.0.0-20240103183307-be819d1f06fc
 	golang.org/x/mod v0.14.0
 	golang.org/x/oauth2 v0.15.0
 	golang.org/x/sync v0.5.0
diff --git a/go.sum b/go.sum
index bb34321..f7c0fb1 100644
--- a/go.sum
+++ b/go.sum
@@ -217,8 +217,8 @@
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20231219180239-dc181d75b848 h1:+iq7lrkxmFNBM7xx+Rae2W6uyPfhPeDWD+n+JgppptE=
 golang.org/x/exp v0.0.0-20231219180239-dc181d75b848/go.mod h1:iRJReGqOEeBhDZGkGbynYwcHlctCvnjTYIamk7uXpHI=
-golang.org/x/exp/event v0.0.0-20231219180239-dc181d75b848 h1:Fg3nHyeMRa3zOGwrxMfgAYbhOJ6tr/inMof9Eaq4Fgk=
-golang.org/x/exp/event v0.0.0-20231219180239-dc181d75b848/go.mod h1:R4Nj8+ac1oNAVEp6jJGgYrsz0uySlWGocGQ5A74W3DY=
+golang.org/x/exp v0.0.0-20240103183307-be819d1f06fc h1:ao2WRsKSzW6KuUY9IWPwWahcHCgR0s52IfwutMfEbdM=
+golang.org/x/exp v0.0.0-20240103183307-be819d1f06fc/go.mod h1:iRJReGqOEeBhDZGkGbynYwcHlctCvnjTYIamk7uXpHI=
 golang.org/x/exp/typeparams v0.0.0-20221208152030-732eee02a75a h1:Jw5wfR+h9mnIYH+OtGT2im5wV1YGGDora5vTv/aa5bE=
 golang.org/x/exp/typeparams v0.0.0-20221208152030-732eee02a75a/go.mod h1:AbB0pIl9nAr9wVwH+Z2ZpaocVmF5I4GyWCDIsVjR0bk=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
diff --git a/internal/observe/observe.go b/internal/observe/observe.go
index 19df286..3fa3fe2 100644
--- a/internal/observe/observe.go
+++ b/internal/observe/observe.go
@@ -8,11 +8,12 @@
 
 import (
 	"context"
+	"golang.org/x/exp/slog"
 	"net/http"
 	"strings"
 
-	"golang.org/x/exp/event"
 	"golang.org/x/vulndb/internal/derrors"
+	"golang.org/x/vulndb/internal/worker/log"
 
 	mexporter "github.com/GoogleCloudPlatform/opentelemetry-operations-go/exporter/metric"
 	texporter "github.com/GoogleCloudPlatform/opentelemetry-operations-go/exporter/trace"
@@ -25,17 +26,13 @@
 	tnoop "go.opentelemetry.io/otel/trace/noop"
 )
 
-// An Observer handles tracing and metrics exporting.
+// An Observer handles tracing, logging and metrics exporting.
 type Observer struct {
 	ctx            context.Context
 	tracerProvider *sdktrace.TracerProvider
 	tracer         trace.Tracer
 	propagator     propagation.TextMapPropagator
-
-	// LogHandlerFunc is invoked in [Observer.Observe] to obtain an
-	// [event.Handler] for logging to be added to the [event.Exporter] in
-	// addition to the tracing and metrics handlers.
-	LogHandlerFunc func(*http.Request) event.Handler
+	baseLogger     *slog.Logger
 }
 
 // NewObserver creates an Observer.
@@ -77,20 +74,21 @@
 			gcppropagator.CloudTraceOneWayPropagator{},
 			propagation.TraceContext{},
 			propagation.Baggage{}),
+		baseLogger: slog.New(log.NewGoogleCloudHandler(slog.LevelDebug)),
 	}, nil
 }
 
 type key struct{}
 
+const (
+	traceIDHeader = "X-Cloud-Trace-Context"
+	gcpTraceKey   = "logging.googleapis.com/trace"
+)
+
 // Observe adds metrics and tracing to an http.Handler.
 func (o *Observer) Observe(h http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		var otherHandler event.Handler
-		if o.LogHandlerFunc != nil {
-			otherHandler = o.LogHandlerFunc(r)
-		}
-		exporter := event.NewExporter(eventHandler{o, otherHandler}, nil)
-		ctx := event.WithExporter(r.Context(), exporter)
+		ctx := log.NewContext(r.Context(), o.baseLogger.With(gcpTraceKey, r.Header.Get(traceIDHeader)))
 		ctx = o.propagator.Extract(ctx, propagation.HeaderCarrier(r.Header))
 		ctx = context.WithValue(ctx, key{}, o)
 		defer o.tracerProvider.ForceFlush(o.ctx)
@@ -98,19 +96,6 @@
 	})
 }
 
-type eventHandler struct {
-	o  *Observer
-	eh event.Handler
-}
-
-// Event implements event.Handler.
-func (h eventHandler) Event(ctx context.Context, ev *event.Event) context.Context {
-	if h.eh != nil {
-		return h.eh.Event(ctx, ev)
-	}
-	return ctx
-}
-
 func Start(ctx context.Context, name string) (context.Context, trace.Span) {
 	if obs, ok := ctx.Value(key{}).(*Observer); ok {
 		return obs.tracer.Start(ctx, name)
diff --git a/internal/worker/log/gcpjson.go b/internal/worker/log/gcpjson.go
deleted file mode 100644
index da45595..0000000
--- a/internal/worker/log/gcpjson.go
+++ /dev/null
@@ -1,86 +0,0 @@
-// Copyright 2021 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package log
-
-import (
-	"context"
-	"fmt"
-	"io"
-	"sync"
-	"time"
-
-	"golang.org/x/exp/event"
-)
-
-// NewGCPJSONLogger returns a handler which logs events in a format that is
-// understood by Google Cloud Platform logging.
-func NewGCPJSONHandler(w io.Writer, traceID string) event.Handler {
-	return &gcpJSONHandler{w: w, traceID: traceID}
-}
-
-type gcpJSONHandler struct {
-	traceID string
-	mu      sync.Mutex // ensure a log line is not interrupted
-	w       io.Writer
-}
-
-// Event implements event.Handler.Event.
-// It handles Log events and ignores all others.
-// See https://cloud.google.com/logging/docs/agent/logging/configuration#special-fields
-// for treatment of special fields.
-func (h *gcpJSONHandler) Event(ctx context.Context, ev *event.Event) context.Context {
-	if ev.Kind != event.LogKind {
-		return ctx
-	}
-	h.mu.Lock()
-	defer h.mu.Unlock()
-
-	fmt.Fprintf(h.w, `{"time": %q`, ev.At.Format(time.RFC3339))
-	if h.traceID != "" {
-		fmt.Fprintf(h.w, `, "logging.googleapis.com/trace": %q`, h.traceID)
-	}
-	gcpLabels := map[string]string{}
-	for _, l := range ev.Labels {
-		var key string
-		switch l.Name {
-		case "msg":
-			key = "message"
-		case "level":
-			key = "severity"
-		default:
-			gcpLabels[l.Name] = l.String() // already quoted, regardless of label kind
-			continue
-		}
-		fmt.Fprintf(h.w, ", %q: ", key)
-		switch {
-		case !l.HasValue():
-			fmt.Fprint(h.w, "null")
-		case l.IsInt64():
-			fmt.Fprintf(h.w, "%d", l.Int64())
-		case l.IsUint64():
-			fmt.Fprintf(h.w, "%d", l.Uint64())
-		case l.IsFloat64():
-			fmt.Fprintf(h.w, "%g", l.Float64())
-		case l.IsBool():
-			fmt.Fprintf(h.w, "%t", l.Bool())
-		default:
-			fmt.Fprintf(h.w, "%q", l.String())
-		}
-	}
-	if len(gcpLabels) > 0 {
-		fmt.Fprintf(h.w, `, "logging.googleapis.com/labels": {`)
-		first := true
-		for k, v := range gcpLabels {
-			if !first {
-				fmt.Fprint(h.w, ", ")
-			}
-			first = false
-			fmt.Fprintf(h.w, "%q: %q", k, v)
-		}
-		fmt.Fprint(h.w, "}")
-	}
-	fmt.Fprint(h.w, "}\n")
-	return ctx
-}
diff --git a/internal/worker/log/gcpjson_test.go b/internal/worker/log/gcpjson_test.go
deleted file mode 100644
index 2ed5409..0000000
--- a/internal/worker/log/gcpjson_test.go
+++ /dev/null
@@ -1,45 +0,0 @@
-// Copyright 2021 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package log
-
-import (
-	"bytes"
-	"context"
-	"testing"
-	"time"
-
-	"golang.org/x/exp/event"
-	"golang.org/x/exp/event/severity"
-)
-
-func TestGCPJSON(t *testing.T) {
-	now := time.Date(2002, 3, 4, 5, 6, 7, 0, time.UTC)
-	for _, test := range []struct {
-		ev   event.Event
-		want string
-	}{
-		{
-			ev: event.Event{
-				At:   now,
-				Kind: event.LogKind,
-				Labels: []event.Label{
-					event.String("msg", "hello"),
-					event.Int64("count", 17),
-					severity.Info.Label(),
-				},
-			},
-			want: `{"time": "2002-03-04T05:06:07Z", "logging.googleapis.com/trace": "tid", "message": "hello", "severity": "info", "logging.googleapis.com/labels": {"count": "17"}}
-`,
-		},
-	} {
-		var buf bytes.Buffer
-		h := &gcpJSONHandler{w: &buf, traceID: "tid"}
-		h.Event(context.Background(), &test.ev)
-		got := buf.String()
-		if got != test.want {
-			t.Errorf("%+v:\ngot  %s\nwant %s", test.ev, got, test.want)
-		}
-	}
-}
diff --git a/internal/worker/log/log.go b/internal/worker/log/log.go
index 2e98142..41e6b01 100644
--- a/internal/worker/log/log.go
+++ b/internal/worker/log/log.go
@@ -8,129 +8,101 @@
 import (
 	"context"
 	"fmt"
+	"golang.org/x/exp/slog"
 	"io"
-	"reflect"
-	"strings"
-	"sync"
+	"os"
 	"time"
-
-	"golang.org/x/exp/event"
-	"golang.org/x/exp/event/severity"
 )
 
-// NewLineHandler returns an event Handler that writes log events one per line
-// in an easy-to-read format:
-//
-//	time level message label1=value1 label2=value2 ...
-func NewLineHandler(w io.Writer) event.Handler {
-	return &lineHandler{w: w}
+type Attrs []slog.Attr
+
+func With(args ...any) Attrs {
+	var r slog.Record
+	r.Add(args...)
+	var as Attrs
+	r.Attrs(func(a slog.Attr) bool {
+		as = append(as, a)
+		return true
+	})
+	return as
 }
 
-type lineHandler struct {
-	mu sync.Mutex // ensure a log line is not interrupted
-	w  io.Writer
+func (as Attrs) Debugf(ctx context.Context, format string, args ...interface{}) {
+	as.logf(ctx, slog.LevelDebug, format, args...)
 }
 
-// Event implements event.Handler.Event for log events.
-func (h *lineHandler) Event(ctx context.Context, ev *event.Event) context.Context {
-	if ev.Kind != event.LogKind {
-		return ctx
-	}
-	h.mu.Lock()
-	defer h.mu.Unlock()
-
-	var msg, level string
-	var others []string
-	for _, lab := range ev.Labels {
-		switch lab.Name {
-		case "msg":
-			msg = lab.String()
-		case "level":
-			level = strings.ToUpper(lab.String())
-		default:
-			others = append(others, fmt.Sprintf("%s=%s", lab.Name, lab.String()))
-		}
-	}
-	var s string
-	if len(others) > 0 {
-		s = " " + strings.Join(others, " ")
-	}
-	if level != "" {
-		level = " " + level
-	}
-	fmt.Fprintf(h.w, "%s%s %s%s\n", ev.At.Format("2006/01/02 15:04:05"), level, msg, s)
-	return ctx
+func (as Attrs) Infof(ctx context.Context, format string, args ...interface{}) {
+	as.logf(ctx, slog.LevelInfo, format, args...)
 }
 
-type Labels []event.Label
-
-func With(kvs ...interface{}) Labels {
-	return Labels(nil).With(kvs...)
+func (as Attrs) Warningf(ctx context.Context, format string, args ...interface{}) {
+	as.logf(ctx, slog.LevelWarn, format, args...)
 }
 
-func (ls Labels) With(kvs ...interface{}) Labels {
-	if len(kvs)%2 != 0 {
-		panic("args must be key-value pairs")
-	}
-	for i := 0; i < len(kvs); i += 2 {
-		ls = append(ls, pairToLabel(kvs[i].(string), kvs[i+1]))
-	}
-	return ls
-}
-
-func pairToLabel(name string, value interface{}) event.Label {
-	if d, ok := value.(time.Duration); ok {
-		return event.Duration(name, d)
-	}
-	v := reflect.ValueOf(value)
-	switch v.Kind() {
-	case reflect.String:
-		return event.String(name, v.String())
-	case reflect.Bool:
-		return event.Bool(name, v.Bool())
-	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-		return event.Int64(name, v.Int())
-	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
-		return event.Uint64(name, v.Uint())
-	case reflect.Float32, reflect.Float64:
-		return event.Float64(name, v.Float())
-	default:
-		return event.Value(name, value)
-	}
-}
-
-func (l Labels) logf(ctx context.Context, s severity.Level, format string, args ...interface{}) {
-	event.Log(ctx, fmt.Sprintf(format, args...), append(l, s.Label())...)
-}
-
-func (l Labels) Debugf(ctx context.Context, format string, args ...interface{}) {
-	l.logf(ctx, severity.Debug, format, args...)
-}
-
-func (l Labels) Infof(ctx context.Context, format string, args ...interface{}) {
-	l.logf(ctx, severity.Info, format, args...)
-}
-
-func (l Labels) Warningf(ctx context.Context, format string, args ...interface{}) {
-	l.logf(ctx, severity.Warning, format, args...)
-}
-
-func (l Labels) Errorf(ctx context.Context, format string, args ...interface{}) {
-	l.logf(ctx, severity.Error, format, args...)
+func (as Attrs) Errorf(ctx context.Context, format string, args ...interface{}) {
+	as.logf(ctx, slog.LevelError, format, args...)
 }
 
 func Debugf(ctx context.Context, format string, args ...interface{}) {
-	Labels(nil).logf(ctx, severity.Debug, format, args...)
+	Attrs{}.logf(ctx, slog.LevelDebug, format, args...)
 }
 
 func Infof(ctx context.Context, format string, args ...interface{}) {
-	Labels(nil).logf(ctx, severity.Info, format, args...)
+	Attrs{}.logf(ctx, slog.LevelInfo, format, args...)
 }
 
 func Warningf(ctx context.Context, format string, args ...interface{}) {
-	Labels(nil).logf(ctx, severity.Warning, format, args...)
+	Attrs{}.logf(ctx, slog.LevelWarn, format, args...)
 }
 
 func Errorf(ctx context.Context, format string, args ...interface{}) {
-	Labels(nil).logf(ctx, severity.Error, format, args...)
+	Attrs{}.logf(ctx, slog.LevelError, format, args...)
+}
+
+func (as Attrs) logf(ctx context.Context, level slog.Level, format string, args ...interface{}) {
+	FromContext(ctx).LogAttrs(ctx, level, fmt.Sprintf(format, args...), as...)
+}
+
+type key struct{}
+
+func FromContext(ctx context.Context) *slog.Logger {
+	if l, ok := ctx.Value(key{}).(*slog.Logger); ok {
+		return l
+	}
+	return slog.Default()
+}
+
+func NewContext(ctx context.Context, l *slog.Logger) context.Context {
+	return context.WithValue(ctx, key{}, l)
+}
+
+// NewGoogleCloudHandler returns a Handler that outputs JSON for the Google
+// Cloud logging service.
+// See https://cloud.google.com/logging/docs/agent/logging/configuration#special-fields
+// for treatment of special fields.
+func NewGoogleCloudHandler(level slog.Leveler) slog.Handler {
+	return newGoogleCloudHandler(level, os.Stderr)
+}
+
+func newGoogleCloudHandler(level slog.Leveler, w io.Writer) slog.Handler {
+	return slog.NewJSONHandler(w, &slog.HandlerOptions{
+		Level:       level,
+		ReplaceAttr: gcpReplaceAttr,
+	})
+}
+
+func gcpReplaceAttr(groups []string, a slog.Attr) slog.Attr {
+	switch a.Key {
+	case "time":
+		if a.Value.Kind() == slog.KindTime {
+			a.Value = slog.StringValue(a.Value.Time().Format(time.RFC3339))
+		}
+	case "msg":
+		a.Key = "message"
+	case "level":
+		a.Key = "severity"
+	case "traceID":
+		a.Key = "logging.googleapis.com/trace"
+	}
+	return a
 }
diff --git a/internal/worker/log/log_test.go b/internal/worker/log/log_test.go
new file mode 100644
index 0000000..c97c253
--- /dev/null
+++ b/internal/worker/log/log_test.go
@@ -0,0 +1,42 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package log
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"golang.org/x/exp/slog"
+	"testing"
+	"time"
+)
+
+// TODO(jba): is it important to put additional attrs under "logging.googleapis.com/labels"?
+
+func TestGoogleCloudHandler(t *testing.T) {
+	var buf bytes.Buffer
+	l := slog.New(newGoogleCloudHandler(slog.LevelInfo, &buf))
+	l = l.With("logging.googleapis.com/trace", "tid")
+	now := time.Now()
+	l.Info("hello", slog.String("foo", "bar"), slog.Int("count", 17))
+	got := buf.String()
+	want := fmt.Sprintf(`{"time":%q,"severity":"INFO","message":"hello","logging.googleapis.com/trace":"tid","foo":"bar","count":17}
+`, now.Format(time.RFC3339))
+	if got != want {
+		t.Errorf("\ngot  %s\nwant %s", got, want)
+	}
+
+	buf.Reset()
+	ctx := NewContext(context.Background(), l)
+	now = time.Now()
+	With("a", "b").Warningf(ctx, "hi")
+	got = buf.String()
+	want = fmt.Sprintf(`{"time":%q,"severity":"WARN","message":"hi","logging.googleapis.com/trace":"tid","a":"b"}
+`, now.Format(time.RFC3339))
+	if got != want {
+		t.Errorf("\ngot  %s\nwant %s", got, want)
+	}
+
+}
diff --git a/internal/worker/server.go b/internal/worker/server.go
index 6aa2794..ca62ee0 100644
--- a/internal/worker/server.go
+++ b/internal/worker/server.go
@@ -22,7 +22,6 @@
 	"cloud.google.com/go/errorreporting"
 	"github.com/google/safehtml/template"
 	"github.com/jba/metrics"
-	"golang.org/x/exp/event"
 	"golang.org/x/sync/errgroup"
 	"golang.org/x/vulndb/internal/cvelistrepo"
 	"golang.org/x/vulndb/internal/derrors"
@@ -52,8 +51,6 @@
 	observer      *observe.Observer
 }
 
-const traceIDHeader = "X-Cloud-Trace-Context"
-
 func NewServer(ctx context.Context, cfg Config) (_ *Server, err error) {
 	defer derrors.Wrap(&err, "NewServer(%q)", cfg.Namespace)
 
@@ -66,11 +63,6 @@
 	// This function will be called for each request.
 	// It lets us install a log handler that knows about the request's
 	// trace ID.
-	s.observer.LogHandlerFunc = func(r *http.Request) event.Handler {
-		traceID := r.Header.Get(traceIDHeader)
-		return log.NewGCPJSONHandler(os.Stderr, traceID)
-	}
-
 	if cfg.UseErrorReporting {
 		reportingClient, err := errorreporting.NewClient(ctx, cfg.Project, errorreporting.Config{
 			ServiceName: serviceID,
diff --git a/internal/worker/worker_test.go b/internal/worker/worker_test.go
index 249ec56..388069c 100644
--- a/internal/worker/worker_test.go
+++ b/internal/worker/worker_test.go
@@ -13,7 +13,6 @@
 	"fmt"
 	"math"
 	"net/http"
-	"os"
 	"sort"
 	"strings"
 	"testing"
@@ -21,7 +20,6 @@
 
 	"github.com/google/go-cmp/cmp"
 	"github.com/google/go-cmp/cmp/cmpopts"
-	"golang.org/x/exp/event"
 	"golang.org/x/vulndb/internal/cveschema"
 	"golang.org/x/vulndb/internal/ghsa"
 	"golang.org/x/vulndb/internal/gitrepo"
@@ -29,7 +27,6 @@
 	"golang.org/x/vulndb/internal/issues/githubtest"
 	"golang.org/x/vulndb/internal/proxy"
 	"golang.org/x/vulndb/internal/report"
-	"golang.org/x/vulndb/internal/worker/log"
 	"golang.org/x/vulndb/internal/worker/store"
 )
 
@@ -97,8 +94,7 @@
 }
 
 func TestCreateIssues(t *testing.T) {
-	ctx := event.WithExporter(context.Background(),
-		event.NewExporter(log.NewLineHandler(os.Stderr), nil))
+	ctx := context.Background()
 	mstore := store.NewMemStore()
 
 	ic, mux := githubtest.Setup(ctx, t, &issues.Config{
@@ -391,8 +387,7 @@
 }
 
 func TestUpdateGHSAs(t *testing.T) {
-	ctx := event.WithExporter(context.Background(),
-		event.NewExporter(log.NewLineHandler(os.Stderr), nil))
+	ctx := context.Background()
 	sas := []*ghsa.SecurityAdvisory{
 		{
 			ID:        "g1",