diff --git a/packages/backend/package.json b/packages/backend/package.json
index 5893599b..8a5e671d 100644
--- a/packages/backend/package.json
+++ b/packages/backend/package.json
@@ -18,6 +18,7 @@
   "dependencies": {
     "@automatisch/web": "0.1.0",
     "@octokit/oauth-methods": "^1.2.6",
+    "ajv-formats": "^2.1.1",
     "axios": "0.24.0",
     "bcrypt": "^5.0.1",
     "cors": "^2.8.5",
diff --git a/packages/backend/src/db/migrations/20211005151457_create_users.ts b/packages/backend/src/db/migrations/20211005151457_create_users.ts
index d74dc3a5..aab544fe 100644
--- a/packages/backend/src/db/migrations/20211005151457_create_users.ts
+++ b/packages/backend/src/db/migrations/20211005151457_create_users.ts
@@ -2,7 +2,7 @@ import { Knex } from "knex";
 
 export async function up(knex: Knex): Promise<void> {
   return knex.schema.createTable('users', (table) => {
-    table.increments('id');
+    table.uuid('id').primary().defaultTo(knex.raw('gen_random_uuid()'));
     table.string('email').unique().notNullable();
     table.string('password').notNullable();
 
diff --git a/packages/backend/src/db/migrations/20211011120732_create_credentials.ts b/packages/backend/src/db/migrations/20211011120732_create_credentials.ts
index 580d2c6d..35a93b18 100644
--- a/packages/backend/src/db/migrations/20211011120732_create_credentials.ts
+++ b/packages/backend/src/db/migrations/20211011120732_create_credentials.ts
@@ -2,11 +2,11 @@ import { Knex } from "knex";
 
 export async function up(knex: Knex): Promise<void> {
   return knex.schema.createTable('credentials', (table) => {
-    table.increments('id');
+    table.uuid('id').primary().defaultTo(knex.raw('gen_random_uuid()'))
     table.string('key').notNullable();
     table.string('display_name').notNullable();
     table.text('data').notNullable();
-    table.integer('user_id').references('id').inTable('users');
+    table.uuid('user_id').references('id').inTable('users');
     table.boolean('verified').defaultTo(false);
 
     table.timestamps(true, true);
diff --git a/packages/backend/src/db/migrations/20211106214730_create_steps.ts b/packages/backend/src/db/migrations/20211106214730_create_steps.ts
index d9135b0f..54cf3488 100644
--- a/packages/backend/src/db/migrations/20211106214730_create_steps.ts
+++ b/packages/backend/src/db/migrations/20211106214730_create_steps.ts
@@ -2,11 +2,11 @@ import { Knex } from 'knex';
 
 export async function up(knex: Knex): Promise<void> {
   return knex.schema.createTable('steps', (table) => {
-    table.increments('id');
+    table.uuid('id').primary().defaultTo(knex.raw('gen_random_uuid()'))
     table.string('key').notNullable();
     table.string('app_key').notNullable();
     table.string('type').notNullable();
-    table.integer('connection_id').references('id').inTable('connections');
+    table.uuid('connection_id').references('id').inTable('connections');
     table.text('parameters');
 
     table.timestamps(true, true);
diff --git a/packages/backend/src/db/migrations/20211122140336_create_flows.ts b/packages/backend/src/db/migrations/20211122140336_create_flows.ts
index 693c8d27..12028680 100644
--- a/packages/backend/src/db/migrations/20211122140336_create_flows.ts
+++ b/packages/backend/src/db/migrations/20211122140336_create_flows.ts
@@ -2,9 +2,9 @@ import { Knex } from "knex";
 
 export async function up(knex: Knex): Promise<void> {
   return knex.schema.createTable('flows', (table) => {
-    table.increments('id');
+    table.uuid('id').primary().defaultTo(knex.raw('gen_random_uuid()'))
     table.string('name');
-    table.integer('user_id').references('id').inTable('users');
+    table.uuid('user_id').references('id').inTable('users');
 
     table.timestamps(true, true);
   });
diff --git a/packages/backend/src/db/migrations/20211122140612_add_flow_id_to_steps.ts b/packages/backend/src/db/migrations/20211122140612_add_flow_id_to_steps.ts
index fb9f6b88..fc223546 100644
--- a/packages/backend/src/db/migrations/20211122140612_add_flow_id_to_steps.ts
+++ b/packages/backend/src/db/migrations/20211122140612_add_flow_id_to_steps.ts
@@ -3,7 +3,7 @@ import { Knex } from "knex";
 export async function up(knex: Knex): Promise<void> {
   return knex.schema.table('steps', (table) => {
     table
-      .integer('flow_id')
+      .uuid('flow_id')
       .references('id')
       .inTable('flows');
   });
diff --git a/packages/backend/src/db/migrations/20220219093113_create_executions.ts b/packages/backend/src/db/migrations/20220219093113_create_executions.ts
index a5140d52..dfba81b8 100644
--- a/packages/backend/src/db/migrations/20220219093113_create_executions.ts
+++ b/packages/backend/src/db/migrations/20220219093113_create_executions.ts
@@ -2,8 +2,8 @@ import { Knex } from 'knex';
 
 export async function up(knex: Knex): Promise<void> {
   return knex.schema.createTable('executions', (table) => {
-    table.increments('id');
-    table.integer('flow_id').references('id').inTable('flows');
+    table.uuid('id').primary().defaultTo(knex.raw('gen_random_uuid()'))
+    table.uuid('flow_id').references('id').inTable('flows');
     table.boolean('test_run').notNullable().defaultTo(false);
 
     table.timestamps(true, true);
diff --git a/packages/backend/src/db/migrations/20220219100800_create_execution_steps.ts b/packages/backend/src/db/migrations/20220219100800_create_execution_steps.ts
index eef61a81..2260056b 100644
--- a/packages/backend/src/db/migrations/20220219100800_create_execution_steps.ts
+++ b/packages/backend/src/db/migrations/20220219100800_create_execution_steps.ts
@@ -2,9 +2,9 @@ import { Knex } from 'knex';
 
 export async function up(knex: Knex): Promise<void> {
   return knex.schema.createTable('execution_steps', (table) => {
-    table.increments('id');
-    table.integer('execution_id').references('id').inTable('executions');
-    table.integer('step_id').references('id').inTable('steps');
+    table.uuid('id').primary().defaultTo(knex.raw('gen_random_uuid()'))
+    table.uuid('execution_id').references('id').inTable('executions');
+    table.uuid('step_id').references('id').inTable('steps');
     table.string('status');
     table.text('data_in');
     table.text('data_out');
diff --git a/packages/backend/src/db/migrations/20220221225537_alter_parameters_column_of_steps.ts b/packages/backend/src/db/migrations/20220221225537_alter_parameters_column_of_steps.ts
index 0f912860..aaeb8d84 100644
--- a/packages/backend/src/db/migrations/20220221225537_alter_parameters_column_of_steps.ts
+++ b/packages/backend/src/db/migrations/20220221225537_alter_parameters_column_of_steps.ts
@@ -2,7 +2,7 @@ import { Knex } from 'knex';
 
 export async function up(knex: Knex): Promise<void> {
   return knex.schema.alterTable('steps', (table) => {
-    table.jsonb('parameters').alter();
+    table.jsonb('parameters').defaultTo('{}').alter();
   });
 }
 
diff --git a/packages/backend/src/graphql/mutations/create-step.ts b/packages/backend/src/graphql/mutations/create-step.ts
index 89e2a48b..8d02cb16 100644
--- a/packages/backend/src/graphql/mutations/create-step.ts
+++ b/packages/backend/src/graphql/mutations/create-step.ts
@@ -7,13 +7,13 @@ type Params = {
     key: string;
     appKey: string;
     flow: {
-      id: number;
+      id: string;
     };
     connection: {
-      id: number;
+      id: string;
     };
     previousStep: {
-      id: number;
+      id: string;
     };
   };
 };
@@ -43,7 +43,6 @@ const createStepResolver = async (
     appKey: input.appKey,
     type: 'action',
     position: previousStep.position + 1,
-    parameters: {},
   });
 
   const nextSteps = await flow
diff --git a/packages/backend/src/models/base.ts b/packages/backend/src/models/base.ts
index 20e5d8bc..1d982bd6 100644
--- a/packages/backend/src/models/base.ts
+++ b/packages/backend/src/models/base.ts
@@ -1,5 +1,6 @@
-import { Model, snakeCaseMappers } from 'objection';
+import { AjvValidator, Model, snakeCaseMappers } from 'objection';
 import type { QueryContext, ModelOptions, ColumnNameMappers } from 'objection';
+import addFormats from 'ajv-formats';
 
 class Base extends Model {
   createdAt!: string;
@@ -9,6 +10,19 @@ class Base extends Model {
     return snakeCaseMappers();
   }
 
+  static createValidator() {
+    return new AjvValidator({
+      onCreateAjv: (ajv) => {
+        addFormats.default(ajv);
+      },
+      options: {
+        allErrors: true,
+        validateSchema: true,
+        ownProperties: true,
+      },
+    });
+  }
+
   async $beforeInsert(queryContext: QueryContext): Promise<void> {
     await super.$beforeInsert(queryContext);
 
diff --git a/packages/backend/src/models/connection.ts b/packages/backend/src/models/connection.ts
index 866fd1b6..997a2b33 100644
--- a/packages/backend/src/models/connection.ts
+++ b/packages/backend/src/models/connection.ts
@@ -20,10 +20,10 @@ class Connection extends Base {
     required: ['key', 'data'],
 
     properties: {
-      id: { type: 'string' },
+      id: { type: 'string', format: 'uuid' },
       key: { type: 'string', minLength: 1, maxLength: 255 },
       data: { type: 'object' },
-      userId: { type: 'string' },
+      userId: { type: 'string', format: 'uuid' },
       verified: { type: 'boolean' },
     },
   };
diff --git a/packages/backend/src/models/execution-step.ts b/packages/backend/src/models/execution-step.ts
index 3f696c31..080efe28 100644
--- a/packages/backend/src/models/execution-step.ts
+++ b/packages/backend/src/models/execution-step.ts
@@ -16,8 +16,8 @@ class ExecutionStep extends Base {
     type: 'object',
 
     properties: {
-      id: { type: 'string' },
-      executionId: { type: 'string' },
+      id: { type: 'string', format: 'uuid' },
+      executionId: { type: 'string', format: 'uuid' },
       stepId: { type: 'string' },
       dataIn: { type: 'object' },
       dataOut: { type: 'object' },
diff --git a/packages/backend/src/models/execution.ts b/packages/backend/src/models/execution.ts
index e4d6772f..7cd11029 100644
--- a/packages/backend/src/models/execution.ts
+++ b/packages/backend/src/models/execution.ts
@@ -14,8 +14,8 @@ class Execution extends Base {
     type: 'object',
 
     properties: {
-      id: { type: 'string' },
-      flowId: { type: 'integer' },
+      id: { type: 'string', format: 'uuid' },
+      flowId: { type: 'string', format: 'uuid' },
       testRun: { type: 'boolean' },
     },
   };
diff --git a/packages/backend/src/models/flow.ts b/packages/backend/src/models/flow.ts
index ee84a915..5d994664 100644
--- a/packages/backend/src/models/flow.ts
+++ b/packages/backend/src/models/flow.ts
@@ -15,9 +15,9 @@ class Flow extends Base {
     type: 'object',
 
     properties: {
-      id: { type: 'string' },
+      id: { type: 'string', format: 'uuid' },
       name: { type: 'string' },
-      userId: { type: 'string' },
+      userId: { type: 'string', format: 'uuid' },
       active: { type: 'boolean' },
     },
   };
diff --git a/packages/backend/src/models/step.ts b/packages/backend/src/models/step.ts
index c8ca29e3..fec08153 100644
--- a/packages/backend/src/models/step.ts
+++ b/packages/backend/src/models/step.ts
@@ -25,12 +25,12 @@ class Step extends Base {
     required: ['type'],
 
     properties: {
-      id: { type: 'string' },
-      flowId: { type: 'string' },
+      id: { type: 'string', format: 'uuid' },
+      flowId: { type: 'string', format: 'uuid' },
       key: { type: ['string', 'null'] },
       appKey: { type: ['string', 'null'], minLength: 1, maxLength: 255 },
       type: { type: 'string', enum: ['action', 'trigger'] },
-      connectionId: { type: ['string', 'null'] },
+      connectionId: { type: ['string', 'null'], format: 'uuid' },
       status: { type: 'string', enum: ['incomplete', 'completed'] },
       position: { type: 'integer' },
       parameters: { type: 'object' },
diff --git a/packages/backend/src/models/user.ts b/packages/backend/src/models/user.ts
index a2c11952..6fa30489 100644
--- a/packages/backend/src/models/user.ts
+++ b/packages/backend/src/models/user.ts
@@ -20,7 +20,7 @@ class User extends Base {
     required: ['email', 'password'],
 
     properties: {
-      id: { type: 'string' },
+      id: { type: 'string', format: 'uuid' },
       email: { type: 'string', format: 'email', minLength: 1, maxLength: 255 },
       password: { type: 'string', minLength: 1, maxLength: 255 },
     },