diff --git a/src/pkg/retention/policy/rule/latest/evaluator.go b/src/pkg/retention/policy/rule/latest/evaluator.go
index 1b9b30fe8..73b165fd4 100644
--- a/src/pkg/retention/policy/rule/latest/evaluator.go
+++ b/src/pkg/retention/policy/rule/latest/evaluator.go
@@ -15,6 +15,8 @@
 package latestk
 
 import (
+	"sort"
+
 	"github.com/goharbor/harbor/src/common/utils/log"
 	"github.com/goharbor/harbor/src/pkg/retention/policy/action"
 	"github.com/goharbor/harbor/src/pkg/retention/policy/rule"
@@ -38,8 +40,20 @@ type evaluator struct {
 
 // Process the candidates based on the rule definition
 func (e *evaluator) Process(artifacts []*res.Candidate) ([]*res.Candidate, error) {
-	// TODO: REPLACE SAMPLE CODE WITH REAL IMPLEMENTATION
-	return artifacts, nil
+	// Sort artifacts by their "active time"
+	//
+	// Active time is defined as the selection of c.PulledTime or c.PushedTime,
+	// whichever is bigger, aka more recent.
+	sort.Slice(artifacts, func(i, j int) bool {
+		return activeTime(artifacts[i]) > activeTime(artifacts[j])
+	})
+
+	i := e.k
+	if i > len(artifacts) {
+		i = len(artifacts)
+	}
+
+	return artifacts[:i], nil
 }
 
 // Specify what action is performed to the candidates processed by this evaluator
@@ -51,7 +65,7 @@ func (e *evaluator) Action() string {
 func New(params rule.Parameters) rule.Evaluator {
 	if params != nil {
 		if param, ok := params[ParameterK]; ok {
-			if v, ok := param.(int); ok {
+			if v, ok := param.(int); ok && v >= 0 {
 				return &evaluator{
 					k: v,
 				}
@@ -66,6 +80,14 @@ func New(params rule.Parameters) rule.Evaluator {
 	}
 }
 
+func activeTime(c *res.Candidate) int64 {
+	if c.PulledTime > c.PushedTime {
+		return c.PulledTime
+	}
+
+	return c.PushedTime
+}
+
 func init() {
 	// Register itself
 	rule.Register(&rule.IndexMeta{
diff --git a/src/pkg/retention/policy/rule/latest/evaluator_test.go b/src/pkg/retention/policy/rule/latest/evaluator_test.go
new file mode 100644
index 000000000..ab2967f51
--- /dev/null
+++ b/src/pkg/retention/policy/rule/latest/evaluator_test.go
@@ -0,0 +1,99 @@
+// Copyright Project Harbor Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package latestk
+
+import (
+	"strconv"
+	"testing"
+
+	"github.com/goharbor/harbor/src/pkg/retention/policy/rule"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/goharbor/harbor/src/pkg/retention/res"
+	"github.com/stretchr/testify/suite"
+)
+
+type EvaluatorTestSuite struct {
+	suite.Suite
+
+	artifacts []*res.Candidate
+}
+
+func (e *EvaluatorTestSuite) SetupSuite() {
+	e.artifacts = []*res.Candidate{
+		{PulledTime: 1, PushedTime: 2},
+		{PulledTime: 3, PushedTime: 4},
+		{PulledTime: 6, PushedTime: 5},
+		{PulledTime: 8, PushedTime: 7},
+		{PulledTime: 9, PushedTime: 9},
+		{PulledTime: 10, PushedTime: 10},
+		{PulledTime: 0, PushedTime: 11},
+	}
+}
+
+func (e *EvaluatorTestSuite) TestProcess() {
+	tests := []struct {
+		k             int
+		expected      int
+		minActiveTime int64
+	}{
+		{k: 0, expected: 0},
+		{k: 1, expected: 1, minActiveTime: 11},
+		{k: 2, expected: 2, minActiveTime: 10},
+		{k: 5, expected: 5, minActiveTime: 6},
+		{k: 6, expected: 6, minActiveTime: 3},
+		{k: 99, expected: len(e.artifacts)},
+	}
+	for _, tt := range tests {
+		e.T().Run(strconv.Itoa(tt.k), func(t *testing.T) {
+			sut := &evaluator{k: tt.k}
+
+			result, err := sut.Process(e.artifacts)
+
+			require.NoError(t, err)
+			require.Len(t, result, tt.expected)
+
+			for _, v := range result {
+				assert.True(t, activeTime(v) >= tt.minActiveTime)
+			}
+		})
+	}
+}
+
+func (e *EvaluatorTestSuite) TestNew() {
+	tests := []struct {
+		name      string
+		params    rule.Parameters
+		expectedK int
+	}{
+		{name: "Valid", params: rule.Parameters{ParameterK: 5}, expectedK: 5},
+		{name: "Default If Negative", params: rule.Parameters{ParameterK: -5}, expectedK: DefaultK},
+		{name: "Default If Wrong Type", params: rule.Parameters{ParameterK: "5"}, expectedK: DefaultK},
+		{name: "Default If Wrong Key", params: rule.Parameters{"n": 5}, expectedK: DefaultK},
+		{name: "Default If Empty", params: rule.Parameters{}, expectedK: DefaultK},
+	}
+	for _, tt := range tests {
+		e.T().Run(tt.name, func(t *testing.T) {
+			sut := New(tt.params).(*evaluator)
+
+			require.Equal(t, tt.expectedK, sut.k)
+		})
+	}
+}
+
+func TestEvaluatorSuite(t *testing.T) {
+	suite.Run(t, &EvaluatorTestSuite{})
+}