diff --git a/MANIFEST b/MANIFEST
index 28b38eb1a..a62312754 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -29,6 +29,7 @@ lib/Zonemaster/Backend/DB.pm
 lib/Zonemaster/Backend/DB/MySQL.pm
 lib/Zonemaster/Backend/DB/PostgreSQL.pm
 lib/Zonemaster/Backend/DB/SQLite.pm
+lib/Zonemaster/Backend/Errors.pm
 lib/Zonemaster/Backend/RPCAPI.pm
 lib/Zonemaster/Backend/TestAgent.pm
 lib/Zonemaster/Backend/Translator.pm
diff --git a/lib/Zonemaster/Backend/DB.pm b/lib/Zonemaster/Backend/DB.pm
index 36f5e5984..09875a82c 100644
--- a/lib/Zonemaster/Backend/DB.pm
+++ b/lib/Zonemaster/Backend/DB.pm
@@ -51,7 +51,8 @@ sub get_db_class {
 sub user_exists {
     my ( $self, $user ) = @_;
 
-    die "username not provided to the method user_exists\n" unless ( $user );
+    die Zonemaster::Backend::Error::Internal->new( reason => "username not provided to the method user_exists")
+        unless ( $user );
 
     return $self->user_exists_in_db( $user );
 }
@@ -59,14 +60,16 @@ sub user_exists {
 sub add_api_user {
     my ( $self, $username, $api_key ) = @_;
 
-    die "username or api_key not provided to the method add_api_user\n"
-      unless ( $username && $api_key );
+    die Zonemaster::Backend::Error::Internal->new( reason => "username or api_key not provided to the method add_api_user")
+        unless ( $username && $api_key );
 
-    die "User already exists\n" if ( $self->user_exists( $username ) );
+    die Zonemaster::Backend::Error::Conflict->new( message => 'User already exists', data => { username => $username } )
+        if ( $self->user_exists( $username ) );
 
     my $result = $self->add_api_user_to_db( $username, $api_key );
 
-    die "add_api_user_to_db not successful\n" unless ( $result );
+    die Zonemaster::Backend::Error::Internal->new( reason => "add_api_user_to_db not successful")
+        unless ( $result );
 
     return $result;
 }
diff --git a/lib/Zonemaster/Backend/DB/MySQL.pm b/lib/Zonemaster/Backend/DB/MySQL.pm
index ef607b51f..d95070993 100644
--- a/lib/Zonemaster/Backend/DB/MySQL.pm
+++ b/lib/Zonemaster/Backend/DB/MySQL.pm
@@ -10,6 +10,7 @@ use DBI qw(:utils);
 use JSON::PP;
 
 use Zonemaster::Backend::Validator qw( untaint_ipv6_address );
+use Zonemaster::Backend::Errors;
 
 with 'Zonemaster::Backend::DB';
 
@@ -128,7 +129,7 @@ sub user_authorized {
 sub create_new_batch_job {
     my ( $self, $username ) = @_;
 
-    my ( $batch_id, $creaton_time ) = $self->dbh->selectrow_array( "
+    my ( $batch_id, $creation_time ) = $self->dbh->selectrow_array( "
             SELECT
                 batch_id,
                 batch_jobs.creation_time AS batch_creation_time
@@ -142,7 +143,8 @@ sub create_new_batch_job {
             LIMIT 1
             ", undef, $username );
 
-    die "You can't create a new batch job, job:[$batch_id] started on:[$creaton_time] still running \n" if ( $batch_id );
+    die Zonemaster::Backend::Error::Conflict->new( message => 'Batch job still running', data => { batch_id => $batch_id, creation_time => $creation_time } )
+        if ( $batch_id );
 
     $self->dbh->do( "INSERT INTO batch_jobs (username) VALUES(?)", undef, $username );
     my ( $new_batch_id ) = $self->dbh->{mysql_insertid};
@@ -228,12 +230,16 @@ sub get_test_params {
 
     my ( $params_json ) = $self->dbh->selectrow_array( "SELECT params FROM test_results WHERE hash_id=?", undef, $test_id );
 
+    die Zonemaster::Backend::Error::ResourceNotFound->new( message => "Test not found", data => { test_id => $test_id } )
+        unless defined $params_json;
+
     my $result;
     eval {
         $result = decode_json( $params_json );
     };
 
-    warn "decoding of params_json failed (testi_id: [$test_id]):".Dumper($params_json) if $@;
+    die Zonemaster::Backend::Error::JsonError->new( reason => "$@", data => { test_id => $test_id } )
+        if $@;
 
     return decode_json( $params_json );
 }
@@ -249,8 +255,22 @@ sub test_results {
     my $result;
     my ( $hrefs ) = $self->dbh->selectall_hashref( "SELECT id, hash_id, CONVERT_TZ(`creation_time`, \@\@session.time_zone, '+00:00') AS creation_time, params, results FROM test_results WHERE hash_id=?", 'hash_id', undef, $test_id );
     $result            = $hrefs->{$test_id};
-    $result->{params}  = decode_json( $result->{params} );
-    $result->{results} = decode_json( $result->{results} );
+
+    die Zonemaster::Backend::Error::ResourceNotFound->new( message => "Test not found", data => { test_id => $test_id } )
+        unless defined $result;
+
+    eval {
+        $result->{params}  = decode_json( $result->{params} );
+
+        if (defined $result->{results}) {
+            $result->{results} = decode_json( $result->{results} );
+        } else {
+            $result->{results} = [];
+        }
+    };
+
+    die Zonemaster::Backend::Error::JsonError->new( reason => "$@", data => { test_id => $test_id } )
+        if $@;
 
     return $result;
 }
@@ -370,7 +390,7 @@ sub add_batch_job {
         $dbh->{AutoCommit} = 1;
     }
     else {
-        die "User $params->{username} not authorized to use batch mode\n";
+        die Zonemaster::Backend::Error::PermissionDenied->new( message => 'User not authorized to use batch mode', data => { username => $params->{username}} );
     }
 
     return $batch_id;
diff --git a/lib/Zonemaster/Backend/DB/PostgreSQL.pm b/lib/Zonemaster/Backend/DB/PostgreSQL.pm
index 908e2aa3c..1177066a7 100644
--- a/lib/Zonemaster/Backend/DB/PostgreSQL.pm
+++ b/lib/Zonemaster/Backend/DB/PostgreSQL.pm
@@ -10,6 +10,7 @@ use Encode;
 use JSON::PP;
 
 use Zonemaster::Backend::DB;
+use Zonemaster::Backend::Errors;
 
 with 'Zonemaster::Backend::DB';
 
@@ -153,8 +154,8 @@ sub create_new_batch_job {
                 test_results.progress<>100
             LIMIT 1
             ", undef, $username );
-
-    die "You can't create a new batch job, job:[$batch_id] started on:[$creation_time] still running \n" if ( $batch_id );
+    die Zonemaster::Backend::Error::Conflict->new( message => 'Batch job still running', data => { batch_id => $batch_id, creation_time => $creation_time } )
+        if ( $batch_id );
 
     my ( $new_batch_id ) =
       $dbh->selectrow_array( "INSERT INTO batch_jobs (username) VALUES (?) RETURNING id", undef, $username );
@@ -207,8 +208,14 @@ sub get_test_params {
 
     my $dbh = $self->dbh;
     my ( $params_json ) = $dbh->selectrow_array( "SELECT params FROM test_results WHERE hash_id=?", undef, $test_id );
+
+    die Zonemaster::Backend::Error::ResourceNotFound->new( message => "Test not found", data => { test_id => $test_id } )
+        unless defined $params_json;
+
     eval { $result = decode_json( encode_utf8( $params_json ) ); };
-    die "$@ \n" if $@;
+
+    die Zonemaster::Backend::Error::JsonError->new( reason => "$@", data => { test_id => $test_id } )
+        if $@;
 
     return $result;
 }
@@ -222,27 +229,36 @@ sub test_results {
       if ( $results );
 
     my $result;
-    eval {
-        my ( $hrefs ) = $dbh->selectall_hashref( "SELECT id, hash_id, creation_time at time zone current_setting('TIMEZONE') at time zone 'UTC' as creation_time, params, results FROM test_results WHERE hash_id=?", 'hash_id', undef, $test_id );
-        $result            = $hrefs->{$test_id};
+    my ( $hrefs ) = $dbh->selectall_hashref( "SELECT id, hash_id, creation_time at time zone current_setting('TIMEZONE') at time zone 'UTC' as creation_time, params, results FROM test_results WHERE hash_id=?", 'hash_id', undef, $test_id );
+    $result = $hrefs->{$test_id};
+
+    die Zonemaster::Backend::Error::ResourceNotFound->new( message => "Test not found", data => { test_id => $test_id } )
+        unless defined $result;
 
+    eval {
         # This workaround is needed to properly handle all versions of perl and the DBD::Pg module
         # More details in the zonemaster backend issue #570
         if (utf8::is_utf8($result->{params}) ) {
-                $result->{params}  = decode_json( encode_utf8($result->{params}) );
+            $result->{params}  = decode_json( encode_utf8($result->{params}) );
         }
         else {
-                $result->{params}  = decode_json( $result->{params} );
+            $result->{params}  = decode_json( $result->{params} );
         }
 
-        if (utf8::is_utf8($result->{results} ) ) {
+        if (defined $result->{results} ) {
+            if (utf8::is_utf8($result->{results} ) ) {
                 $result->{results}  = decode_json( encode_utf8($result->{results}) );
-        }
-        else {
+            }
+            else {
                 $result->{results}  = decode_json( $result->{results} );
+            }
+        } else {
+            $result->{results} = [];
         }
     };
-    die "$@ \n" if $@;
+
+    die Zonemaster::Backend::Error::JsonError->new( reason => "$@", data => { test_id => $test_id })
+        if $@;
 
     return $result;
 }
@@ -342,7 +358,7 @@ sub add_batch_job {
         $dbh->commit();
     }
     else {
-        die "User $params->{username} not authorized to use batch mode\n";
+        die Zonemaster::Backend::Error::PermissionDenied->new( message => 'User not authorized to use batch mode', data => { username => $params->{username}} );
     }
 
     return $batch_id;
diff --git a/lib/Zonemaster/Backend/DB/SQLite.pm b/lib/Zonemaster/Backend/DB/SQLite.pm
index 7dc784e3c..72919151e 100644
--- a/lib/Zonemaster/Backend/DB/SQLite.pm
+++ b/lib/Zonemaster/Backend/DB/SQLite.pm
@@ -11,6 +11,8 @@ use Digest::MD5 qw(md5_hex);
 use JSON::PP;
 use Log::Any qw( $log );
 
+use Zonemaster::Backend::Errors;
+
 with 'Zonemaster::Backend::DB';
 
 has 'dbh' => (
@@ -145,7 +147,7 @@ sub user_authorized {
 sub create_new_batch_job {
     my ( $self, $username ) = @_;
 
-    my ( $batch_id, $creaton_time ) = $self->dbh->selectrow_array( "
+    my ( $batch_id, $creation_time ) = $self->dbh->selectrow_array( "
                SELECT
                     batch_id,
                     batch_jobs.creation_time AS batch_creation_time
@@ -158,7 +160,8 @@ sub create_new_batch_job {
                LIMIT 1
                " );
 
-    die "You can't create a new batch job, job:[$batch_id] started on:[$creaton_time] still running \n" if ( $batch_id );
+    die Zonemaster::Backend::Error::Conflict->new( message => 'Batch job still running', data => { batch_id => $batch_id, creation_time => $creation_time } )
+        if ( $batch_id );
 
     $self->dbh->do("INSERT INTO batch_jobs (username) VALUES(" . $self->dbh->quote( $username ) . ")" );
     my ( $new_batch_id ) = $self->dbh->sqlite_last_insert_rowid;
@@ -244,12 +247,16 @@ sub get_test_params {
 
     my ( $params_json ) = $self->dbh->selectrow_array( "SELECT params FROM test_results WHERE hash_id=?", undef, $test_id );
 
+    die Zonemaster::Backend::Error::ResourceNotFound->new( message => "Test not found", data => { test_id => $test_id } )
+        unless defined $params_json;
+
     my $result;
     eval {
         $result = decode_json( $params_json );
     };
 
-    $log->warn( "decoding of params_json failed (test_id: [$test_id]):".Dumper($params_json) ) if $@;
+    die Zonemaster::Backend::Error::JsonError->new( reason => "$@", data => { test_id => $test_id } )
+        if $@;
 
     return $result;
 }
@@ -265,8 +272,22 @@ sub test_results {
     my $result;
     my ( $hrefs ) = $self->dbh->selectall_hashref( "SELECT id, hash_id, creation_time, params, results FROM test_results WHERE hash_id=?", 'hash_id', undef, $test_id );
     $result            = $hrefs->{$test_id};
-    $result->{params}  = decode_json( $result->{params} );
-    $result->{results} = decode_json( $result->{results} );
+
+    die Zonemaster::Backend::Error::ResourceNotFound->new( message => "Test not found", data => { test_id => $test_id } )
+        unless defined $result;
+
+    eval {
+        $result->{params}  = decode_json( $result->{params} );
+
+        if (defined $result->{results}) {
+            $result->{results} = decode_json( $result->{results} );
+        } else {
+            $result->{results} = [];
+        }
+    };
+
+    die Zonemaster::Backend::Error::JsonError->new( reason => "$@", data => { test_id => $test_id } )
+        if $@;
 
     return $result;
 }
@@ -363,7 +384,7 @@ sub add_batch_job {
         $dbh->{AutoCommit} = 1;
     }
     else {
-        die "User $params->{username} not authorized to use batch mode\n";
+        die Zonemaster::Backend::Error::PermissionDenied->new( message => 'User not authorized to use batch mode', data => { username => $params->{username}} );
     }
 
     return $batch_id;
diff --git a/lib/Zonemaster/Backend/Errors.pm b/lib/Zonemaster/Backend/Errors.pm
new file mode 100644
index 000000000..cc25cf877
--- /dev/null
+++ b/lib/Zonemaster/Backend/Errors.pm
@@ -0,0 +1,157 @@
+package Zonemaster::Backend::Error;
+use Moose;
+use Data::Dumper;
+
+
+has 'message' => (
+    is => 'ro',
+    isa => 'Str',
+    required => 1,
+);
+
+has 'code' => (
+    is => 'ro',
+    isa => 'Int',
+    required => 1,
+);
+
+has 'data' => (
+    is => 'ro',
+    isa => 'Any',
+    default => undef,
+);
+
+sub as_hash {
+    my $self = shift;
+    my $error = {
+        code => $self->code,
+        message => $self->message,
+        error => ref($self),
+    };
+    $error->{data} = $self->data if defined $self->data;
+    return $error;
+}
+
+sub as_string {
+    my $self = shift;
+    my $str = sprintf "%s (code %d).", $self->message, $self->code;
+    if (defined $self->data) {
+        $str .= sprintf " Context: %s", $self->_data_dump;
+    }
+    return $str;
+}
+
+sub _data_dump {
+    my $self = shift;
+    local $Data::Dumper::Indent = 0;
+    local $Data::Dumper::Terse = 1;
+    my $data = Dumper($self->data);
+    $data =~ s/[\n\r]/ /g;
+    return $data ;
+}
+
+package Zonemaster::Backend::Error::Internal;
+use Moose;
+
+extends 'Zonemaster::Backend::Error';
+
+has '+message' => (
+    default => 'Internal server error'
+);
+
+has '+code' => (
+    default => -32603
+);
+
+has 'reason' => (
+    isa => 'Str',
+    is => 'ro'
+);
+
+has 'method' => (
+    is => 'ro',
+    isa => 'Str',
+    builder => '_build_method'
+);
+
+sub _build_method {
+    my $s = 0;
+    while (my @c = caller($s)) {
+        $s ++;
+        last if $c[3] eq 'Moose::Object::new';
+    }
+    my @c = caller($s);
+    if ($c[3] =~ /^(.*)::handle_exception$/ ) {
+        @c = caller(++$s);
+    }
+
+    return $c[3];
+}
+
+around 'BUILDARGS', sub {
+    my ($orig, $class, %args) = @_;
+
+    if(exists $args{reason}) {
+        # trim new lines
+        $args{reason} =~ s/\n/ /g;
+        $args{reason} =~ s/^\s+|\s+$//g;
+    }
+
+    $class->$orig(%args);
+};
+
+sub as_string {
+    my $self = shift;
+    my $str = sprintf "Caught %s in the `%s` method: %s", ref($self), $self->method, $self->reason;
+    if (defined $self->data) {
+        $str .= sprintf " Context: %s", $self->_data_dump;
+    }
+    return $str;
+}
+
+
+package Zonemaster::Backend::Error::ResourceNotFound;
+use Moose;
+
+extends 'Zonemaster::Backend::Error';
+
+has '+message' => (
+    default => 'Resource not found'
+);
+
+has '+code' => (
+    default => -32000
+);
+
+package Zonemaster::Backend::Error::PermissionDenied;
+use Moose;
+
+extends 'Zonemaster::Backend::Error';
+
+has '+message' => (
+    default => 'Permission denied'
+);
+
+has '+code' => (
+    default => -32001
+);
+
+package Zonemaster::Backend::Error::Conflict;
+use Moose;
+
+extends 'Zonemaster::Backend::Error';
+
+has '+message' => (
+    default => 'Conflicting resource'
+);
+
+has '+code' => (
+    default => -32002
+);
+
+package Zonemaster::Backend::Error::JsonError;
+use Moose;
+
+extends 'Zonemaster::Backend::Error::Internal';
+
+1;
diff --git a/lib/Zonemaster/Backend/RPCAPI.pm b/lib/Zonemaster/Backend/RPCAPI.pm
index fae0d9b31..b36a05813 100644
--- a/lib/Zonemaster/Backend/RPCAPI.pm
+++ b/lib/Zonemaster/Backend/RPCAPI.pm
@@ -26,6 +26,7 @@ use Zonemaster::Backend;
 use Zonemaster::Backend::Config;
 use Zonemaster::Backend::Translator;
 use Zonemaster::Backend::Validator;
+use Zonemaster::Backend::Errors;
 
 my $zm_validator = Zonemaster::Backend::Validator->new;
 my %json_schemas;
@@ -43,7 +44,7 @@ sub new {
     bless( $self, $type );
 
     if ( ! $params || ! $params->{config} ) {
-        handle_exception('new', "Missing 'config' parameter", '001');
+        handle_exception("Missing 'config' parameter");
     }
 
     $self->{config} = $params->{config};
@@ -67,18 +68,27 @@ sub _init_db {
         my $dbclass = Zonemaster::Backend::DB->get_db_class( $dbtype );
         $self->{db} = $dbclass->from_config( $self->{config} );
     };
+
     if ($@) {
-        handle_exception('_init_db', "Failed to initialize the [$dbtype] database backend module: [$@]", '002');
+        handle_exception("Failed to initialize the [$dbtype] database backend module: [$@]");
     }
 }
 
 sub handle_exception {
-    my ( $method, $exception, $exception_id ) = @_;
+    my ( $exception ) = @_;
+
+    if ( !$exception->isa('Zonemaster::Backend::Error') ) {
+        my $reason = $exception;
+        $exception = Zonemaster::Backend::Error::Internal->new( reason => $reason );
+    }
+
+    if ( $exception->isa('Zonemaster::Backend::Error::Internal') ) {
+        $log->error($exception->as_string);
+    } else {
+        $log->info($exception->as_string);
+    }
 
-    $exception =~ s/\n/ /g;
-    $exception =~ s/^\s+|\s+$//g;
-    $log->error("Internal error $exception_id: Unexpected error in the $method API call: [$exception]");
-    die "Internal error $exception_id \n";
+    die $exception->as_hash;
 }
 
 $json_schemas{version_info} = joi->object->strict;
@@ -92,7 +102,7 @@ sub version_info {
 
     };
     if ($@) {
-        handle_exception('version_info', $@, '003');
+        handle_exception( $@ );
     }
 
     return \%ver;
@@ -105,7 +115,7 @@ sub profile_names {
     my %profiles;
     eval { %profiles = $self->{config}->PUBLIC_PROFILES };
     if ( $@ ) {
-        handle_exception( 'profile_names', $@, '004' );
+        handle_exception( $@ );
     }
 
     return [ keys %profiles ];
@@ -146,7 +156,7 @@ sub get_host_by_name {
 
     };
     if ($@) {
-        handle_exception('get_host_by_name', $@, '005');
+        handle_exception( $@ );
     }
 
     return \@adresses;
@@ -196,7 +206,7 @@ sub get_data_from_parent_zone {
         return \%result;
     };
     if ($@) {
-        handle_exception('get_data_from_parent_zone', $@, '006');
+        handle_exception( $@ );
     }
     elsif ($result) {
         return $result;
@@ -290,7 +300,7 @@ $extra_validators{start_domain_test} = sub {
         return @errors;
     };
     if ($@) {
-        handle_exception('start_domain_test_validate_syntax', $@, '008');
+        handle_exception( $@ );
     }
     else {
         return @errors;
@@ -330,7 +340,7 @@ sub start_domain_test {
         $result = $self->{db}->create_new_test( $params->{domain}, $params, $self->{config}->ZONEMASTER_age_reuse_previous_test );
     };
     if ($@) {
-        handle_exception('start_domain_test', $@, '009');
+        handle_exception( $@ );
     }
 
     return $result;
@@ -348,7 +358,7 @@ sub test_progress {
         $result = $self->{db}->test_progress( $test_id );
     };
     if ($@) {
-        handle_exception('test_progress', $@, '010');
+        handle_exception( $@ );
     }
 
     return $result;
@@ -368,7 +378,7 @@ sub get_test_params {
         $result = $self->{db}->get_test_params( $test_id );
     };
     if ($@) {
-        handle_exception('get_test_params', $@, '011');
+        handle_exception( $@ );
     }
 
     return $result;
@@ -409,7 +419,7 @@ sub get_test_results {
 
     my $previous_locale = $translator->locale;
     if ( !$translator->locale( $locale ) ) {
-        handle_exception( 'get_test_results', "Failed to set locale: $locale", '017' );
+        handle_exception( "Failed to set locale: $locale" );
     }
 
     eval { $translator->data } if $translator;    # Provoke lazy loading of translation data
@@ -468,7 +478,7 @@ sub get_test_results {
         $result->{results} = \@zm_results;
     };
     if ($@) {
-        handle_exception('get_test_results', $@, '012');
+        handle_exception( $@ );
     }
 
     $translator->locale( $previous_locale );
@@ -500,7 +510,7 @@ sub get_test_history {
         $results = $self->{db}->get_test_history( $params );
     };
     if ($@) {
-        handle_exception('get_test_history', $@, '013');
+        handle_exception( $@ );
     }
 
     return $results;
@@ -529,7 +539,7 @@ sub add_api_user {
         }
     };
     if ($@) {
-        handle_exception('add_api_user', $@, '014');
+        handle_exception( $@ );
     }
 
     return $result;
@@ -569,7 +579,7 @@ sub add_batch_job {
         $results = $self->{db}->add_batch_job( $params );
     };
     if ($@) {
-        handle_exception('add_batch_job', $@, '015');
+        handle_exception( $@ );
     }
 
     return $results;
@@ -589,7 +599,7 @@ sub get_batch_job_result {
         $result = $self->{db}->get_batch_job_result($batch_id);
     };
     if ($@) {
-        handle_exception('get_batch_job_result', $@, '016');
+        handle_exception( $@ );
     }
 
     return $result;