diff --git a/config-resolver-go/go.mod b/config-resolver-go/go.mod
new file mode 100644
index 0000000..647e11a
--- /dev/null
+++ b/config-resolver-go/go.mod
@@ -0,0 +1,3 @@
+module configresolver
+
+go 1.23.8
diff --git a/config-resolver-go/resolver/dto/config.go b/config-resolver-go/resolver/dto/config.go
new file mode 100644
index 0000000..e8e3cab
--- /dev/null
+++ b/config-resolver-go/resolver/dto/config.go
@@ -0,0 +1,8 @@
+package dto
+
+// Config describes the configuration input for Json resolver
+
+type Config struct {
+	OverrideRules     []OverrideRule         `json:"override-rules"`
+	DefaultProperties map[string]interface{} `json:"default-properties"`
+}
diff --git a/config-resolver-go/resolver/dto/override_rule.go b/config-resolver-go/resolver/dto/override_rule.go
new file mode 100644
index 0000000..50aa6ab
--- /dev/null
+++ b/config-resolver-go/resolver/dto/override_rule.go
@@ -0,0 +1,11 @@
+package dto
+
+// OverrideRule defines the conditions and properties for override
+
+type OverrideRule struct {
+	UserIsInAllGroups       []string               `json:"user-is-in-all-groups"`
+	UserIsInAnyGroup        []string               `json:"user-is-in-any-group"`
+	UserIsInNoneOfTheGroups []string               `json:"user-is-none-of-the-groups"`
+	CustomExpression        string                 `json:"custom-expression"`
+	Override                map[string]interface{} `json:"override"`
+}
diff --git a/config-resolver-go/resolver/json_service.go b/config-resolver-go/resolver/json_service.go
new file mode 100644
index 0000000..29550e1
--- /dev/null
+++ b/config-resolver-go/resolver/json_service.go
@@ -0,0 +1,223 @@
+package resolver
+
+import (
+	"encoding/json"
+	"fmt"
+	"go/ast"
+	"go/parser"
+	"go/token"
+	"regexp"
+	"strings"
+
+	"configresolver/resolver/dto"
+)
+
+// JsonConfigResolverService is an implementation of ConfigResolver for JSON configuration.
+type JsonConfigResolverService struct {
+	configToResolve string
+}
+
+func NewJsonConfigResolverService() *JsonConfigResolverService {
+	return &JsonConfigResolverService{}
+}
+
+func (s *JsonConfigResolverService) SetConfigToResolve(config string) {
+	s.configToResolve = config
+}
+
+func (s *JsonConfigResolverService) ResolveConfig(userGroups []string) (string, error) {
+	if s.configToResolve == "" {
+		return "", ErrConfigNotSet
+	}
+	return s.ResolveConfigFrom(s.configToResolve, userGroups)
+}
+
+func (s *JsonConfigResolverService) ResolveConfigAs(userGroups []string, result interface{}) error {
+	if s.configToResolve == "" {
+		return ErrConfigNotSet
+	}
+	return s.ResolveConfigFromAs(s.configToResolve, userGroups, result)
+}
+
+func (s *JsonConfigResolverService) ResolveConfigFrom(config string, userGroups []string) (string, error) {
+	var out map[string]interface{}
+	if err := s.resolve(config, userGroups, &out); err != nil {
+		return "", err
+	}
+	data, err := json.Marshal(out)
+	return string(data), err
+}
+
+func (s *JsonConfigResolverService) ResolveConfigFromAs(config string, userGroups []string, result interface{}) error {
+	var out map[string]interface{}
+	if err := s.resolve(config, userGroups, &out); err != nil {
+		return err
+	}
+	data, err := json.Marshal(out)
+	if err != nil {
+		return err
+	}
+	return json.Unmarshal(data, result)
+}
+
+func (s *JsonConfigResolverService) resolve(config string, userGroups []string, out *map[string]interface{}) error {
+	var cfg dto.Config
+	if err := json.Unmarshal([]byte(config), &cfg); err != nil {
+		return err
+	}
+	groups := make(map[string]bool)
+	if cfg.DefaultProperties == nil {
+		return fmt.Errorf("invalid config: missing default-properties")
+	}
+	for _, g := range userGroups {
+		groups[g] = true
+	}
+	for _, rule := range cfg.OverrideRules {
+		applies, err := ruleApplies(groups, rule)
+		if err != nil {
+			return err
+		}
+		if applies {
+			applyOverride(cfg.DefaultProperties, rule.Override)
+		}
+	}
+	*out = cfg.DefaultProperties
+	return nil
+}
+
+func ruleApplies(groups map[string]bool, rule dto.OverrideRule) (bool, error) {
+	if len(rule.UserIsInAllGroups) > 0 {
+		match := true
+		for _, g := range rule.UserIsInAllGroups {
+			if !groups[g] {
+				match = false
+				break
+			}
+		}
+		if match {
+			return true, nil
+		}
+	}
+	if len(rule.UserIsInAnyGroup) > 0 {
+		for _, g := range rule.UserIsInAnyGroup {
+			if groups[g] {
+				return true, nil
+			}
+		}
+	}
+	if len(rule.UserIsInNoneOfTheGroups) > 0 {
+		none := true
+		for _, g := range rule.UserIsInNoneOfTheGroups {
+			if groups[g] {
+				none = false
+				break
+			}
+		}
+		if none {
+			return true, nil
+		}
+	}
+	if rule.CustomExpression != "" {
+		val, err := evaluateExpression(rule.CustomExpression, groups)
+		if err != nil {
+			return false, err
+		}
+		if val {
+			return true, nil
+		}
+	}
+	return false, nil
+}
+
+func applyOverride(base map[string]interface{}, override map[string]interface{}) {
+	for k, v := range override {
+		overrideProperty(base, k, v)
+	}
+}
+
+func overrideProperty(node map[string]interface{}, path string, value interface{}) {
+	parts := strings.Split(path, ".")
+	for i, p := range parts {
+		if i == len(parts)-1 {
+			node[p] = value
+			return
+		}
+		next, ok := node[p]
+		if !ok {
+			newMap := make(map[string]interface{})
+			node[p] = newMap
+			node = newMap
+			continue
+		}
+		m, ok := next.(map[string]interface{})
+		if !ok {
+			m = make(map[string]interface{})
+			node[p] = m
+		}
+		node = m
+	}
+}
+
+var containsRe = regexp.MustCompile(`#user\.contains\('([^']+)'\)`) // pattern for user.contains('group')
+
+func evaluateExpression(expr string, groups map[string]bool) (bool, error) {
+	replaced := containsRe.ReplaceAllStringFunc(expr, func(s string) string {
+		m := containsRe.FindStringSubmatch(s)
+		if len(m) == 2 && groups[m[1]] {
+			return "true"
+		}
+		return "false"
+	})
+	replaced = strings.ReplaceAll(replaced, " and ", " && ")
+	replaced = strings.ReplaceAll(replaced, " or ", " || ")
+	replaced = strings.ReplaceAll(replaced, " not ", " ! ")
+
+	parsed, err := parser.ParseExpr(replaced)
+	if err != nil {
+		return false, err
+	}
+	return evalBoolAST(parsed)
+}
+
+func evalBoolAST(e ast.Expr) (bool, error) {
+	switch v := e.(type) {
+	case *ast.ParenExpr:
+		return evalBoolAST(v.X)
+	case *ast.UnaryExpr:
+		if v.Op != token.NOT {
+			return false, fmt.Errorf("unsupported unary op")
+		}
+		val, err := evalBoolAST(v.X)
+		if err != nil {
+			return false, err
+		}
+		return !val, nil
+	case *ast.BinaryExpr:
+		left, err := evalBoolAST(v.X)
+		if err != nil {
+			return false, err
+		}
+		right, err := evalBoolAST(v.Y)
+		if err != nil {
+			return false, err
+		}
+		switch v.Op {
+		case token.LAND:
+			return left && right, nil
+		case token.LOR:
+			return left || right, nil
+		default:
+			return false, fmt.Errorf("unsupported binary op")
+		}
+	case *ast.Ident:
+		if v.Name == "true" {
+			return true, nil
+		}
+		if v.Name == "false" {
+			return false, nil
+		}
+		return false, fmt.Errorf("unknown identifier %s", v.Name)
+	default:
+		return false, fmt.Errorf("unsupported expr")
+	}
+}
diff --git a/config-resolver-go/resolver/json_service_test.go b/config-resolver-go/resolver/json_service_test.go
new file mode 100644
index 0000000..199c421
--- /dev/null
+++ b/config-resolver-go/resolver/json_service_test.go
@@ -0,0 +1,107 @@
+package resolver
+
+import (
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+type TestDTOProperty3dash1 struct {
+	Property3Dash1Dash1 bool `json:"property3-1-1"`
+}
+
+type TestDTOProperty3 struct {
+	Property3Dash1 TestDTOProperty3dash1 `json:"property3-1"`
+}
+
+type TestDTOProperty2 struct {
+	Property2Dash1 bool `json:"property2-1"`
+}
+
+type TestDTO struct {
+	Property1 int              `json:"property1"`
+	Property2 TestDTOProperty2 `json:"property2"`
+	Property3 TestDTOProperty3 `json:"property3"`
+}
+
+func buildPath(parts ...string) string {
+	return filepath.Join(append([]string{"testdata"}, parts...)...)
+}
+
+func prepareService() *JsonConfigResolverService {
+	return NewJsonConfigResolverService()
+}
+
+func TestResolveConfigScenarios(t *testing.T) {
+	tests := []struct {
+		groups  []string
+		inFile  string
+		outFile string
+	}{
+		{[]string{"group-a", "group-b"}, buildPath("user-in-all-groups", "input.json"), buildPath("user-in-all-groups", "output.json")},
+		{[]string{"group-d"}, buildPath("user-in-any-groups", "input.json"), buildPath("user-in-any-groups", "output.json")},
+		{[]string{"group-c"}, buildPath("user-in-no-groups", "input.json"), buildPath("user-in-no-groups", "output.json")},
+		{[]string{"group-a", "group-b", "group-c"}, buildPath("user-in-different-groups", "input.json"), buildPath("user-in-different-groups", "output.json")},
+		{[]string{"group-a", "group-b", "group-c"}, buildPath("custom-user-groups", "input.json"), buildPath("custom-user-groups", "output.json")},
+	}
+
+	svc := prepareService()
+
+	for _, tt := range tests {
+		inputCfg, err := readFile(tt.inFile)
+		if err != nil {
+			t.Fatal(err)
+		}
+		var expected TestDTO
+		if err := readFileIntoObject(tt.outFile, &expected); err != nil {
+			t.Fatal(err)
+		}
+
+		var actual TestDTO
+		if err := svc.ResolveConfigFromAs(inputCfg, tt.groups, &actual); err != nil {
+			t.Fatal(err)
+		}
+		if expected != actual {
+			t.Errorf("unexpected result for %v", tt)
+		}
+		outStr, err := svc.ResolveConfigFrom(inputCfg, tt.groups)
+		if err != nil {
+			t.Fatal(err)
+		}
+		expectedStr, err := readFile(tt.outFile)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if normalize(outStr) != normalize(expectedStr) {
+			t.Errorf("string result mismatch for %v", tt)
+		}
+	}
+}
+
+func normalize(s string) string {
+	s = strings.ReplaceAll(s, "\n", "")
+	s = strings.ReplaceAll(s, " ", "")
+	return s
+}
+
+func TestInvalidConfig(t *testing.T) {
+	svc := prepareService()
+	groups := []string{"group-a", "group-b"}
+	input, err := readFile(buildPath("invalid-config", "input.json"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := svc.ResolveConfigFrom(input, groups); err == nil {
+		t.Errorf("expected error")
+	}
+	if err := svc.ResolveConfigFromAs(input, groups, &TestDTO{}); err == nil {
+		t.Errorf("expected error")
+	}
+	svc.SetConfigToResolve(input)
+	if _, err := svc.ResolveConfig(groups); err == nil {
+		t.Errorf("expected error")
+	}
+	if err := svc.ResolveConfigAs(groups, &TestDTO{}); err == nil {
+		t.Errorf("expected error")
+	}
+}
diff --git a/config-resolver-go/resolver/resolver.go b/config-resolver-go/resolver/resolver.go
new file mode 100644
index 0000000..ee143fd
--- /dev/null
+++ b/config-resolver-go/resolver/resolver.go
@@ -0,0 +1,14 @@
+package resolver
+
+import "errors"
+
+// ConfigResolver defines methods for resolving configuration for user groups.
+type ConfigResolver interface {
+	SetConfigToResolve(config string)
+	ResolveConfig(userGroups []string) (string, error)
+	ResolveConfigAs(userGroups []string, result interface{}) error
+	ResolveConfigFrom(config string, userGroups []string) (string, error)
+	ResolveConfigFromAs(config string, userGroups []string, result interface{}) error
+}
+
+var ErrConfigNotSet = errors.New("config to resolve is null. Use SetConfigToResolve() method to set the config")
diff --git a/config-resolver-go/resolver/testdata/custom-user-groups/input.json b/config-resolver-go/resolver/testdata/custom-user-groups/input.json
new file mode 100644
index 0000000..c07e77d
--- /dev/null
+++ b/config-resolver-go/resolver/testdata/custom-user-groups/input.json
@@ -0,0 +1,21 @@
+{
+  "override-rules": [
+    {
+      "custom-expression": "#user.contains('group-a') or #user.contains('group-b') or #user.contains('group-c')",
+      "override": {
+        "property3.property3-1.property3-1-1": true
+      }
+    }
+  ],
+  "default-properties": {
+    "property1": 1,
+    "property2": {
+      "property2-1": true
+    },
+    "property3": {
+      "property3-1": {
+        "property3-1-1": false
+      }
+    }
+  }
+}
diff --git a/config-resolver-go/resolver/testdata/custom-user-groups/output.json b/config-resolver-go/resolver/testdata/custom-user-groups/output.json
new file mode 100644
index 0000000..4833969
--- /dev/null
+++ b/config-resolver-go/resolver/testdata/custom-user-groups/output.json
@@ -0,0 +1,11 @@
+{
+  "property1": 1,
+  "property2": {
+    "property2-1": true
+  },
+  "property3": {
+    "property3-1": {
+      "property3-1-1": true
+    }
+  }
+}
diff --git a/config-resolver-go/resolver/testdata/invalid-config/input.json b/config-resolver-go/resolver/testdata/invalid-config/input.json
new file mode 100644
index 0000000..98ee6a6
--- /dev/null
+++ b/config-resolver-go/resolver/testdata/invalid-config/input.json
@@ -0,0 +1,6 @@
+{
+  "override-rules": [
+  ],
+  "default-propertiesssssssss": {
+  }
+}
diff --git a/config-resolver-go/resolver/testdata/user-in-all-groups/input.json b/config-resolver-go/resolver/testdata/user-in-all-groups/input.json
new file mode 100644
index 0000000..3015432
--- /dev/null
+++ b/config-resolver-go/resolver/testdata/user-in-all-groups/input.json
@@ -0,0 +1,21 @@
+{
+  "override-rules": [
+     {
+       "user-is-in-all-groups": ["group-a","group-b"],
+       "override": {
+         "property1": 2
+       }
+     }
+  ],
+  "default-properties": {
+    "property1": 1,
+    "property2": {
+      "property2-1": true
+    },
+    "property3": {
+      "property3-1": {
+        "property3-1-1": false
+      }
+    }
+  }
+}
diff --git a/config-resolver-go/resolver/testdata/user-in-all-groups/output.json b/config-resolver-go/resolver/testdata/user-in-all-groups/output.json
new file mode 100644
index 0000000..fce12cf
--- /dev/null
+++ b/config-resolver-go/resolver/testdata/user-in-all-groups/output.json
@@ -0,0 +1,11 @@
+{
+  "property1": 2,
+  "property2": {
+    "property2-1": true
+  },
+  "property3": {
+    "property3-1": {
+      "property3-1-1": false
+    }
+  }
+}
diff --git a/config-resolver-go/resolver/testdata/user-in-any-groups/input.json b/config-resolver-go/resolver/testdata/user-in-any-groups/input.json
new file mode 100644
index 0000000..8b9a0b6
--- /dev/null
+++ b/config-resolver-go/resolver/testdata/user-in-any-groups/input.json
@@ -0,0 +1,24 @@
+{
+  "override-rules": [
+    {
+      "user-is-in-any-group": [
+        "group-c",
+        "group-d"
+      ],
+      "override": {
+        "property2.property2-1": false
+      }
+    }
+  ],
+  "default-properties": {
+    "property1": 1,
+    "property2": {
+      "property2-1": true
+    },
+    "property3": {
+      "property3-1": {
+        "property3-1-1": false
+      }
+    }
+  }
+}
diff --git a/config-resolver-go/resolver/testdata/user-in-any-groups/output.json b/config-resolver-go/resolver/testdata/user-in-any-groups/output.json
new file mode 100644
index 0000000..d57bbb4
--- /dev/null
+++ b/config-resolver-go/resolver/testdata/user-in-any-groups/output.json
@@ -0,0 +1,11 @@
+{
+  "property1": 1,
+  "property2": {
+    "property2-1": false
+  },
+  "property3": {
+    "property3-1": {
+      "property3-1-1": false
+    }
+  }
+}
diff --git a/config-resolver-go/resolver/testdata/user-in-different-groups/input.json b/config-resolver-go/resolver/testdata/user-in-different-groups/input.json
new file mode 100644
index 0000000..486742d
--- /dev/null
+++ b/config-resolver-go/resolver/testdata/user-in-different-groups/input.json
@@ -0,0 +1,48 @@
+{
+  "override-rules": [
+    {
+      "user-is-in-all-groups": [
+        "group-a",
+        "group-b"
+      ],
+      "override": {
+        "property1": 2
+      }
+    },
+    {
+      "user-is-in-any-group": [
+        "group-c",
+        "group-d"
+      ],
+      "override": {
+        "property2.property2-1": false
+      }
+    },
+    {
+      "user-is-none-of-the-groups": [
+        "group-e",
+        "group-f"
+      ],
+      "override": {
+        "property2.property2-1": false
+      }
+    },
+    {
+      "custom-expression": "#user.contains('group-a') or #user.contains('group-b') or #user.contains('group-c')",
+      "override": {
+        "property3.property3-1.property3-1-1": true
+      }
+    }
+  ],
+  "default-properties": {
+    "property1": 1,
+    "property2": {
+      "property2-1": true
+    },
+    "property3": {
+      "property3-1": {
+        "property3-1-1": false
+      }
+    }
+  }
+}
diff --git a/config-resolver-go/resolver/testdata/user-in-different-groups/output.json b/config-resolver-go/resolver/testdata/user-in-different-groups/output.json
new file mode 100644
index 0000000..f0034fb
--- /dev/null
+++ b/config-resolver-go/resolver/testdata/user-in-different-groups/output.json
@@ -0,0 +1,11 @@
+{
+  "property1": 2,
+  "property2": {
+    "property2-1": false
+  },
+  "property3": {
+    "property3-1": {
+      "property3-1-1": true
+    }
+  }
+}
diff --git a/config-resolver-go/resolver/testdata/user-in-no-groups/input.json b/config-resolver-go/resolver/testdata/user-in-no-groups/input.json
new file mode 100644
index 0000000..94b329b
--- /dev/null
+++ b/config-resolver-go/resolver/testdata/user-in-no-groups/input.json
@@ -0,0 +1,21 @@
+{
+  "override-rules": [
+    {
+      "user-is-none-of-the-groups": ["group-e","group-f"],
+      "override": {
+        "property2.property2-1": false
+      }
+    }
+  ],
+  "default-properties": {
+    "property1": 1,
+    "property2": {
+      "property2-1": true
+    },
+    "property3": {
+      "property3-1": {
+        "property3-1-1": false
+      }
+    }
+  }
+}
diff --git a/config-resolver-go/resolver/testdata/user-in-no-groups/output.json b/config-resolver-go/resolver/testdata/user-in-no-groups/output.json
new file mode 100644
index 0000000..d57bbb4
--- /dev/null
+++ b/config-resolver-go/resolver/testdata/user-in-no-groups/output.json
@@ -0,0 +1,11 @@
+{
+  "property1": 1,
+  "property2": {
+    "property2-1": false
+  },
+  "property3": {
+    "property3-1": {
+      "property3-1-1": false
+    }
+  }
+}
diff --git a/config-resolver-go/resolver/utils_test.go b/config-resolver-go/resolver/utils_test.go
new file mode 100644
index 0000000..51ee8e4
--- /dev/null
+++ b/config-resolver-go/resolver/utils_test.go
@@ -0,0 +1,22 @@
+package resolver
+
+import (
+	"encoding/json"
+	"io/ioutil"
+)
+
+func readFile(p string) (string, error) {
+	b, err := ioutil.ReadFile(p)
+	if err != nil {
+		return "", err
+	}
+	return string(b), nil
+}
+
+func readFileIntoObject(p string, out interface{}) error {
+	data, err := ioutil.ReadFile(p)
+	if err != nil {
+		return err
+	}
+	return json.Unmarshal(data, out)
+}