diff --git a/pom.xml b/pom.xml
index 7099dd8cbc..8729aa8f5c 100644
--- a/pom.xml
+++ b/pom.xml
@@ -894,6 +894,7 @@
                 <module>tensorflow-java</module>
                 <module>testing-modules</module>
                 <module>testing-modules/mockito-simple</module>
+                <module>timefold-solver</module>
                 <module>vaadin</module>
                 <module>vavr-modules</module>
                 <module>vertx-modules</module>
@@ -1139,6 +1140,7 @@
                 <module>tensorflow-java</module>
                 <module>testing-modules</module>
                 <module>testing-modules/mockito-simple</module>
+                <module>timefold-solver</module>
                 <module>vaadin</module>
                 <module>vavr-modules</module>
                 <module>vertx-modules</module>
diff --git a/timefold-solver/README.md b/timefold-solver/README.md
new file mode 100644
index 0000000000..b7a2dbe14b
--- /dev/null
+++ b/timefold-solver/README.md
@@ -0,0 +1,7 @@
+## OptaPlanner
+
+This module contains articles about OptaPlanner.
+
+### Relevant articles
+
+- [A Guide to OptaPlanner](https://www.baeldung.com/opta-planner)
diff --git a/timefold-solver/pom.xml b/timefold-solver/pom.xml
new file mode 100644
index 0000000000..2a219a593c
--- /dev/null
+++ b/timefold-solver/pom.xml
@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>timefold-solver</artifactId>
+    <name>timefold-solver</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>ai.timefold.solver</groupId>
+                <artifactId>timefold-solver-bom</artifactId>
+                <version>${version.ai.timefold.solver}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+    <dependencies>
+        <dependency>
+            <groupId>ai.timefold.solver</groupId>
+            <artifactId>timefold-solver-core</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>ai.timefold.solver</groupId>
+            <artifactId>timefold-solver-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
+        <version.ai.timefold.solver>1.4.0</version.ai.timefold.solver>
+    </properties>
+
+</project>
diff --git a/timefold-solver/src/main/java/com/baeldung/timefoldsolver/Employee.java b/timefold-solver/src/main/java/com/baeldung/timefoldsolver/Employee.java
new file mode 100644
index 0000000000..c755896201
--- /dev/null
+++ b/timefold-solver/src/main/java/com/baeldung/timefoldsolver/Employee.java
@@ -0,0 +1,32 @@
+package com.baeldung.timefoldsolver;
+
+import java.util.Set;
+
+public class Employee {
+
+    private String name;
+    private Set<String> skills;
+
+    public Employee(String name, Set<String> skills) {
+        this.name = name;
+        this.skills = skills;
+    }
+
+    @Override
+    public String toString() {
+        return name;
+    }
+
+    // ************************************************************************
+    // Getters and setters
+    // ************************************************************************
+
+    public String getName() {
+        return name;
+    }
+
+    public Set<String> getSkills() {
+        return skills;
+    }
+
+}
diff --git a/timefold-solver/src/main/java/com/baeldung/timefoldsolver/Shift.java b/timefold-solver/src/main/java/com/baeldung/timefoldsolver/Shift.java
new file mode 100644
index 0000000000..04087134c6
--- /dev/null
+++ b/timefold-solver/src/main/java/com/baeldung/timefoldsolver/Shift.java
@@ -0,0 +1,57 @@
+package com.baeldung.timefoldsolver;
+
+import java.time.LocalDateTime;
+
+import ai.timefold.solver.core.api.domain.entity.PlanningEntity;
+import ai.timefold.solver.core.api.domain.variable.PlanningVariable;
+
+@PlanningEntity
+public class Shift {
+
+    private LocalDateTime start;
+    private LocalDateTime end;
+    private String requiredSkill;
+
+    @PlanningVariable
+    private Employee employee;
+
+    // A no-arg constructor is required for @PlanningEntity annotated classes
+    public Shift() {}
+
+    public Shift(LocalDateTime start, LocalDateTime end, String requiredSkill) {
+        this(start, end, requiredSkill, null);
+    }
+
+    public Shift(LocalDateTime start, LocalDateTime end, String requiredSkill, Employee employee) {
+        this.start = start;
+        this.end = end;
+        this.requiredSkill = requiredSkill;
+        this.employee = employee;
+    }
+
+    @Override
+    public String toString() {
+        return start + " - " + end;
+    }
+
+    // ************************************************************************
+    // Getters and setters
+    // ************************************************************************
+
+    public LocalDateTime getStart() {
+        return start;
+    }
+
+    public LocalDateTime getEnd() {
+        return end;
+    }
+
+    public String getRequiredSkill() {
+        return requiredSkill;
+    }
+
+    public Employee getEmployee() {
+        return employee;
+    }
+
+}
diff --git a/timefold-solver/src/main/java/com/baeldung/timefoldsolver/ShiftSchedule.java b/timefold-solver/src/main/java/com/baeldung/timefoldsolver/ShiftSchedule.java
new file mode 100644
index 0000000000..85abc8eb66
--- /dev/null
+++ b/timefold-solver/src/main/java/com/baeldung/timefoldsolver/ShiftSchedule.java
@@ -0,0 +1,47 @@
+package com.baeldung.timefoldsolver;
+
+import java.util.List;
+
+import ai.timefold.solver.core.api.domain.solution.PlanningEntityCollectionProperty;
+import ai.timefold.solver.core.api.domain.solution.PlanningScore;
+import ai.timefold.solver.core.api.domain.solution.PlanningSolution;
+import ai.timefold.solver.core.api.domain.valuerange.ValueRangeProvider;
+import ai.timefold.solver.core.api.score.buildin.hardsoft.HardSoftScore;
+
+@PlanningSolution
+public class ShiftSchedule {
+
+    @ValueRangeProvider
+    private List<Employee> employees;
+    @PlanningEntityCollectionProperty
+    private List<Shift> shifts;
+
+    @PlanningScore
+    private HardSoftScore score = null;
+
+    // A no-arg constructor is required for @PlanningSolution annotated classes
+    public ShiftSchedule() {
+    }
+
+    public ShiftSchedule(List<Employee> employees, List<Shift> shifts) {
+        this.employees = employees;
+        this.shifts = shifts;
+    }
+
+    // ************************************************************************
+    // Getters and setters
+    // ************************************************************************
+
+    public List<Employee> getEmployees() {
+        return employees;
+    }
+
+    public List<Shift> getShifts() {
+        return shifts;
+    }
+
+    public HardSoftScore getScore() {
+        return score;
+    }
+
+}
diff --git a/timefold-solver/src/main/java/com/baeldung/timefoldsolver/ShiftScheduleApp.java b/timefold-solver/src/main/java/com/baeldung/timefoldsolver/ShiftScheduleApp.java
new file mode 100644
index 0000000000..9c25922dea
--- /dev/null
+++ b/timefold-solver/src/main/java/com/baeldung/timefoldsolver/ShiftScheduleApp.java
@@ -0,0 +1,54 @@
+package com.baeldung.timefoldsolver;
+
+import java.time.Duration;
+import java.time.LocalDate;
+import java.util.List;
+import java.util.Set;
+
+import ai.timefold.solver.core.api.solver.Solver;
+import ai.timefold.solver.core.api.solver.SolverFactory;
+import ai.timefold.solver.core.config.solver.SolverConfig;
+
+public class ShiftScheduleApp {
+
+    public static void main(String[] args) {
+        SolverFactory<ShiftSchedule> solverFactory = SolverFactory.create(new SolverConfig()
+                .withSolutionClass(ShiftSchedule.class)
+                .withEntityClasses(Shift.class)
+                .withConstraintProviderClass(ShiftScheduleConstraintProvider.class)
+                // The solver runs only for 5 seconds on this small dataset.
+                // It's recommended to run for at least 5 minutes ("5m") otherwise.
+                .withTerminationSpentLimit(Duration.ofSeconds(5)));
+        Solver<ShiftSchedule> solver = solverFactory.buildSolver();
+
+        ShiftSchedule problem = loadProblem();
+        ShiftSchedule solution = solver.solve(problem);
+        printSolution(solution);
+    }
+
+    private static ShiftSchedule loadProblem() {
+        LocalDate monday = LocalDate.of(2030, 4, 1);
+        LocalDate tuesday = LocalDate.of(2030, 4, 2);
+        return new ShiftSchedule(List.of(
+                new Employee("Ann", Set.of("Bartender")),
+                new Employee("Beth", Set.of("Waiter", "Bartender")),
+                new Employee("Carl", Set.of("Waiter"))
+        ), List.of(
+                new Shift(monday.atTime(6, 0), monday.atTime(14, 0), "Waiter"),
+                new Shift(monday.atTime(9, 0), monday.atTime(17, 0), "Bartender"),
+                new Shift(monday.atTime(14, 0), monday.atTime(22, 0), "Bartender"),
+                new Shift(tuesday.atTime(6, 0), tuesday.atTime(14, 0), "Waiter"),
+                new Shift(tuesday.atTime(14, 0), tuesday.atTime(22, 0), "Bartender")
+        ));
+    }
+
+    private static void printSolution(ShiftSchedule solution) {
+        System.out.println("Shift assignments");
+        for (Shift shift : solution.getShifts()) {
+            System.out.println("  " + shift.getStart().toLocalDate()
+                    + " " + shift.getStart().toLocalTime() + " - " + shift.getEnd().toLocalTime()
+                    + ": " + shift.getEmployee().getName());
+        }
+    }
+
+}
diff --git a/timefold-solver/src/main/java/com/baeldung/timefoldsolver/ShiftScheduleConstraintProvider.java b/timefold-solver/src/main/java/com/baeldung/timefoldsolver/ShiftScheduleConstraintProvider.java
new file mode 100644
index 0000000000..0846429460
--- /dev/null
+++ b/timefold-solver/src/main/java/com/baeldung/timefoldsolver/ShiftScheduleConstraintProvider.java
@@ -0,0 +1,37 @@
+package com.baeldung.timefoldsolver;
+
+import ai.timefold.solver.core.api.score.buildin.hardsoft.HardSoftScore;
+import ai.timefold.solver.core.api.score.stream.Constraint;
+import ai.timefold.solver.core.api.score.stream.ConstraintFactory;
+import ai.timefold.solver.core.api.score.stream.ConstraintProvider;
+
+import static ai.timefold.solver.core.api.score.stream.Joiners.equal;
+
+public class ShiftScheduleConstraintProvider implements ConstraintProvider {
+
+    @Override
+    public Constraint[] defineConstraints(ConstraintFactory constraintFactory) {
+        return new Constraint[] {
+                atMostOneShiftPerDay(constraintFactory),
+                requiredSkill(constraintFactory)
+        };
+    }
+
+    public Constraint atMostOneShiftPerDay(ConstraintFactory constraintFactory) {
+        return constraintFactory.forEach(Shift.class)
+                .join(Shift.class,
+                        equal(shift -> shift.getStart().toLocalDate()),
+                        equal(Shift::getEmployee))
+                .filter((shift1, shift2) -> shift1 != shift2)
+                .penalize(HardSoftScore.ONE_HARD)
+                .asConstraint("At most one shift per day");
+    }
+
+    public Constraint requiredSkill(ConstraintFactory constraintFactory) {
+        return constraintFactory.forEach(Shift.class)
+                .filter(shift -> !shift.getEmployee().getSkills().contains(shift.getRequiredSkill()))
+                .penalize(HardSoftScore.ONE_HARD)
+                .asConstraint("Required skill");
+    }
+
+}
diff --git a/timefold-solver/src/test/java/com/baeldung/timefoldsolver/ShiftScheduleConstraintProviderTest.java b/timefold-solver/src/test/java/com/baeldung/timefoldsolver/ShiftScheduleConstraintProviderTest.java
new file mode 100644
index 0000000000..9979f5d5e0
--- /dev/null
+++ b/timefold-solver/src/test/java/com/baeldung/timefoldsolver/ShiftScheduleConstraintProviderTest.java
@@ -0,0 +1,50 @@
+package com.baeldung.timefoldsolver;
+
+import java.time.LocalDate;
+import java.util.Set;
+
+import ai.timefold.solver.test.api.score.stream.ConstraintVerifier;
+import org.junit.jupiter.api.Test;
+
+class ShiftScheduleConstraintProviderTest {
+
+    private static final LocalDate MONDAY = LocalDate.of(2030, 4, 1);
+    private static final LocalDate TUESDAY = LocalDate.of(2030, 4, 2);
+
+    ConstraintVerifier<ShiftScheduleConstraintProvider, ShiftSchedule> constraintVerifier = ConstraintVerifier.build(
+            new ShiftScheduleConstraintProvider(), ShiftSchedule.class, Shift.class);
+
+    @Test
+    void atMostOneShiftPerDay() {
+        Employee ann = new Employee("Ann", null);
+        constraintVerifier.verifyThat(ShiftScheduleConstraintProvider::atMostOneShiftPerDay)
+                .given(
+                        ann,
+                        new Shift(MONDAY.atTime(6, 0), MONDAY.atTime(14, 0), null, ann),
+                        new Shift(MONDAY.atTime(14, 0), MONDAY.atTime(22, 0), null, ann))
+                // Penalizes both A-B and B-A. To avoid that, use forEachUniquePair() in the constraint instead.
+                .penalizesBy(2);
+        constraintVerifier.verifyThat(ShiftScheduleConstraintProvider::atMostOneShiftPerDay)
+                .given(
+                        ann,
+                        new Shift(MONDAY.atTime(6, 0), MONDAY.atTime(14, 0), null, ann),
+                        new Shift(TUESDAY.atTime(14, 0), TUESDAY.atTime(22, 0), null, ann))
+                .penalizesBy(0);
+    }
+
+    @Test
+    void requiredSkill() {
+        Employee ann = new Employee("Ann", Set.of("Waiter"));
+        constraintVerifier.verifyThat(ShiftScheduleConstraintProvider::requiredSkill)
+                .given(
+                        ann,
+                        new Shift(MONDAY.atTime(6, 0), MONDAY.atTime(14, 0), "Cook", ann))
+                .penalizesBy(1);
+        constraintVerifier.verifyThat(ShiftScheduleConstraintProvider::requiredSkill)
+                .given(
+                        ann,
+                        new Shift(MONDAY.atTime(6, 0), MONDAY.atTime(14, 0), "Waiter", ann))
+                .penalizesBy(0);
+    }
+
+}