diff --git a/lang/backend-tgg/driver/src/main/resources/tools/vitruv/optggs/driver/templates/AttributeConstraints.jte b/lang/backend-tgg/driver/src/main/resources/tools/vitruv/optggs/driver/templates/AttributeConstraints.jte
index ea273633..d3a5ac9d 100644
--- a/lang/backend-tgg/driver/src/main/resources/tools/vitruv/optggs/driver/templates/AttributeConstraints.jte
+++ b/lang/backend-tgg/driver/src/main/resources/tools/vitruv/optggs/driver/templates/AttributeConstraints.jte
@@ -3,8 +3,8 @@
 @param Project p
 
 @for(ConstraintSolver solver : p.constraintSolvers())
-attributeConstraint ${solver.name()}(${String.join(", ", solver.parameters().stream().map(param -> param + ": " + solver.parameterType(param)).toList())}) {
+attributeConstraint ${solver.name()}(${solver.parameters().stream().map(param -> param + ": " + solver.parameterType(param)).collect(Collectors.joining(", "))}) {
     ${String.join(", ", solver.supportedBindings())}
     gen: ${String.join(", ", solver.supportedGenBindings())}
 }
-@endfor
\ No newline at end of file
+@endfor
diff --git a/lang/backend-tgg/emsl-parser/src/main/java/tools/vitruv/neojoin/tgg/emsl_parser/EmslParser.java b/lang/backend-tgg/emsl-parser/src/main/java/tools/vitruv/neojoin/tgg/emsl_parser/EmslParser.java
index 4eff38b8..f858341d 100644
--- a/lang/backend-tgg/emsl-parser/src/main/java/tools/vitruv/neojoin/tgg/emsl_parser/EmslParser.java
+++ b/lang/backend-tgg/emsl-parser/src/main/java/tools/vitruv/neojoin/tgg/emsl_parser/EmslParser.java
@@ -11,6 +11,7 @@
 import org.emoflon.neo.emsl.EMSLStandaloneSetup;
 
 import java.util.List;
+import java.util.stream.Collectors;
 
 public final class EmslParser {
 
@@ -44,6 +45,6 @@ public static List<EObject> parse(String path) {
     }
 
     private static String generateIssuesMessage(List<Issue> issues) {
-        return String.join(System.lineSeparator(), issues.stream().map(Issue::getMessage).toList());
+        return issues.stream().map(Issue::getMessage).collect(Collectors.joining(System.lineSeparator()));
     }
 }
diff --git a/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/Containment.java b/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/Containment.java
index d6d4ec4b..e87ca205 100644
--- a/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/Containment.java
+++ b/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/Containment.java
@@ -6,6 +6,7 @@
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.stream.Collectors;
 
 /**
  * A containment of another element
@@ -91,7 +92,7 @@ public Containment filter(Filter filter) {
 
     @Override
     public String toString() {
-        var f = String.join(", ", filters.stream().map(Object::toString).toList());
+        var f = filters.stream().map(Object::toString).collect(Collectors.joining( ", "));
         if (!f.isEmpty()) {
             f = " | " + f;
         }
diff --git a/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/Link.java b/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/Link.java
index 739f3024..46f60640 100644
--- a/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/Link.java
+++ b/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/Link.java
@@ -6,6 +6,7 @@
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.stream.Collectors;
 
 /**
  * A reference from one element to another
@@ -175,7 +176,7 @@ public Link filter(Filter filter) {
 
     @Override
     public String toString() {
-        var f = String.join(", ", filters.stream().map(Object::toString).toList());
+        var f = filters.stream().map(Object::toString).collect(Collectors.joining(", "));
         if (!f.isEmpty()) {
             f = " | " + f;
         }
diff --git a/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/Query.java b/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/Query.java
index 02c8a006..2ce0bb2d 100644
--- a/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/Query.java
+++ b/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/Query.java
@@ -9,6 +9,7 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 /**
  * A single query consisting of multiple operators
@@ -145,10 +146,10 @@ public Mapping topMapping() {
 
     @Override
     public String toString() {
-        var p = String.join(".", projections.stream().map(Object::toString).toList());
-        var f = String.join(".", filters.stream().map(Object::toString).toList());
-        var c = String.join(".", containments.stream().map(Object::toString).toList());
-        var l = String.join(".", links.stream().map(Object::toString).toList());
+        var p = projections.stream().map(Object::toString).collect(Collectors.joining("."));
+        var f = filters.stream().map(Object::toString).collect(Collectors.joining("."));
+        var c = containments.stream().map(Object::toString).collect(Collectors.joining("."));
+        var l = links.stream().map(Object::toString).collect(Collectors.joining("."));
         return selection + f + p + c + l;
     }
 }
diff --git a/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/selection/Join.java b/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/selection/Join.java
index 066f3a93..c68ddb3d 100644
--- a/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/selection/Join.java
+++ b/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/selection/Join.java
@@ -6,6 +6,7 @@
 import java.util.Collection;
 import java.util.List;
 import java.util.Objects;
+import java.util.stream.Collectors;
 
 public class Join implements PatternLink {
     private final FQN element;
@@ -37,7 +38,7 @@ public List<Tuple<String, String>> constrainedProperties() {
 
     @Override
     public String toString() {
-        var conditions = String.join(",", constrainedProperties.stream().map(props -> props.first() + "==" + props.last()).toList());
+        var conditions = constrainedProperties.stream().map(props -> props.first() + "==" + props.last()).collect(Collectors.joining(","));
         return " ⨝(" + conditions + ") " + element.fqn();
     }
 
diff --git a/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/selection/Pattern.java b/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/selection/Pattern.java
index 22065009..95576211 100644
--- a/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/selection/Pattern.java
+++ b/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/selection/Pattern.java
@@ -5,6 +5,7 @@
 import tools.vitruv.optggs.operators.Tuple;
 
 import java.util.*;
+import java.util.stream.Collectors;
 
 public class Pattern {
     private final List<PatternLink> links;
@@ -109,7 +110,7 @@ public boolean startsWith(Pattern other) {
 
     @Override
     public String toString() {
-        return String.join("", links.stream().map(Object::toString).toList());
+        return links.stream().map(Object::toString).collect(Collectors.joining());
     }
 
     @Override
@@ -122,4 +123,4 @@ public boolean equals(Object o) {
     public int hashCode() {
         return Objects.hashCode(links);
     }
-}
\ No newline at end of file
+}
diff --git a/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/selection/Union.java b/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/selection/Union.java
index f7313077..b0c1ada7 100644
--- a/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/selection/Union.java
+++ b/lang/backend-tgg/operators/src/main/java/tools/vitruv/optggs/operators/selection/Union.java
@@ -4,6 +4,7 @@
 import tools.vitruv.optggs.operators.Mapping;
 
 import java.util.*;
+import java.util.stream.Collectors;
 
 public class Union {
     private final List<Pattern> branches = new ArrayList<>();
@@ -51,7 +52,7 @@ public boolean anyStartWith(Pattern pattern) {
 
     @Override
     public String toString() {
-        return String.join(" UNION ", branches.stream().map(Object::toString).toList());
+        return branches.stream().map(Object::toString).collect(Collectors.joining( " UNION "));
     }
 
     public interface Resolver {
diff --git a/lang/backend-tgg/transpiler/src/main/java/tools/vitruv/optggs/transpiler/operators/ResolvedContainment.java b/lang/backend-tgg/transpiler/src/main/java/tools/vitruv/optggs/transpiler/operators/ResolvedContainment.java
index 487b4b2a..5813f78a 100644
--- a/lang/backend-tgg/transpiler/src/main/java/tools/vitruv/optggs/transpiler/operators/ResolvedContainment.java
+++ b/lang/backend-tgg/transpiler/src/main/java/tools/vitruv/optggs/transpiler/operators/ResolvedContainment.java
@@ -8,6 +8,9 @@
 
 import java.util.Collection;
 import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
 
 public class ResolvedContainment implements RuleGenerator, Mappable {
     private final ResolvedPattern source;
@@ -54,7 +57,7 @@ private void extendSlice(Slice slice, ResolvedPattern pattern) {
 
     @Override
     public String toString() {
-        var f = String.join(", ", filters.stream().map(Object::toString).toList());
+        var f = filters.stream().map(Object::toString).collect(Collectors.joining(", "));
         if (!f.isEmpty()) {
             f = " | " + f;
         }
diff --git a/lang/backend-tgg/transpiler/src/main/java/tools/vitruv/optggs/transpiler/operators/ResolvedLink.java b/lang/backend-tgg/transpiler/src/main/java/tools/vitruv/optggs/transpiler/operators/ResolvedLink.java
index 9a96acfe..848fbacb 100644
--- a/lang/backend-tgg/transpiler/src/main/java/tools/vitruv/optggs/transpiler/operators/ResolvedLink.java
+++ b/lang/backend-tgg/transpiler/src/main/java/tools/vitruv/optggs/transpiler/operators/ResolvedLink.java
@@ -6,6 +6,7 @@
 
 import java.util.Collection;
 import java.util.List;
+import java.util.stream.Collectors;
 
 public class ResolvedLink implements RuleGenerator {
     private final ResolvedPattern source;
@@ -48,7 +49,7 @@ private void extendSlice(Slice slice, ResolvedPattern pattern) {
 
     @Override
     public String toString() {
-        var f = String.join(", ", filters.stream().map(Object::toString).toList());
+        var f = filters.stream().map(Object::toString).collect(Collectors.joining( ", "));
         if (!f.isEmpty()) {
             f = " | " + f;
         }
diff --git a/lang/backend-tgg/transpiler/src/main/java/tools/vitruv/optggs/transpiler/operators/patterns/ResolvedJoin.java b/lang/backend-tgg/transpiler/src/main/java/tools/vitruv/optggs/transpiler/operators/patterns/ResolvedJoin.java
index 7539bb6b..b83430be 100644
--- a/lang/backend-tgg/transpiler/src/main/java/tools/vitruv/optggs/transpiler/operators/patterns/ResolvedJoin.java
+++ b/lang/backend-tgg/transpiler/src/main/java/tools/vitruv/optggs/transpiler/operators/patterns/ResolvedJoin.java
@@ -10,6 +10,7 @@
 import java.util.Collection;
 import java.util.List;
 import java.util.Objects;
+import java.util.stream.Collectors;
 
 public class ResolvedJoin implements ResolvedPatternLink {
     private final FQN element;
@@ -38,7 +39,7 @@ public Node extendSlice(Slice slice, Node lastNode) {
 
     @Override
     public String toString() {
-        var conditions = String.join(",", constrainedProperties.stream().map(props -> props.first() + "==" + props.last()).toList());
+        var conditions = constrainedProperties.stream().map(props -> props.first() + "==" + props.last()).collect(Collectors.joining(","));
         return " ⨝(" + conditions + ") " + element.fqn();
     }
 
diff --git a/lang/backend-tgg/transpiler/src/main/java/tools/vitruv/optggs/transpiler/operators/patterns/ResolvedPattern.java b/lang/backend-tgg/transpiler/src/main/java/tools/vitruv/optggs/transpiler/operators/patterns/ResolvedPattern.java
index f8a3b2b4..1ed09d90 100644
--- a/lang/backend-tgg/transpiler/src/main/java/tools/vitruv/optggs/transpiler/operators/patterns/ResolvedPattern.java
+++ b/lang/backend-tgg/transpiler/src/main/java/tools/vitruv/optggs/transpiler/operators/patterns/ResolvedPattern.java
@@ -9,6 +9,7 @@
 import java.util.Collection;
 import java.util.List;
 import java.util.Objects;
+import java.util.stream.Collectors;
 
 public class ResolvedPattern {
     private final List<ResolvedPatternLink> links;
@@ -56,7 +57,7 @@ public Tuple<ResolvedPattern, ResolvedPatternLink> popBottom() {
     }
 
     public Tuple<ResolvedPattern, ResolvedPatternLink> popTop() {
-        var first = links.get(0);
+        var first = links.getFirst();
         var remainder = links.subList(1, links.size());
         return new Tuple<>(new ResolvedPattern(remainder), first);
     }
@@ -74,7 +75,7 @@ public boolean startsWith(ResolvedPattern other) {
 
     @Override
     public String toString() {
-        return String.join("", links.stream().map(Object::toString).toList());
+        return links.stream().map(Object::toString).collect(Collectors.joining(""));
     }
 
     @Override