diff --git a/BlueWest.Data/DataQueryResult.cs b/BlueWest.Data/DataQueryResult.cs
index 64fc9c7..b9ecc04 100644
--- a/BlueWest.Data/DataQueryResult.cs
+++ b/BlueWest.Data/DataQueryResult.cs
@@ -4,25 +4,32 @@ using System.Text;
 
 namespace BlueWest.Data
 {
-    class DataQueryResult { }
-
-    internal sealed class PositiveResult<T> : DataQueryResult
+    public sealed class DataQueryResult<T>
     {
         public readonly T Value;
+        public bool HasValue;
+        public string Message;
 
-        public PositiveResult(T value)
+        public DataQueryResult(T value, bool success = true, string message = "")
         {
             Value = value;
+            HasValue = success;
+            Message = message;
         }
     }
-
-
-    internal sealed class NegativeResult : DataQueryResult
+  internal sealed class DataQueryResult
     {
-        public readonly string UserMessage;
-        public NegativeResult(string userMessage)
+        public readonly object Value;
+        public bool HasValue;
+        public string Message;
+
+        public DataQueryResult(object value, bool success = true, string message = "")
         {
-            UserMessage = userMessage;
+            Value = value;
+            HasValue = success;
+            Message = message;
         }
     }
+
+
 }
diff --git a/BlueWest.Data/User/User.cs b/BlueWest.Data/User/User.cs
index 2062814..3e9e56d 100644
--- a/BlueWest.Data/User/User.cs
+++ b/BlueWest.Data/User/User.cs
@@ -25,9 +25,9 @@ namespace BlueWest.Data
         [Key(6)] public double BTCAmount { get; set; }
         [Key(7)] public double LTCAmount { get; set; }
 
-        [Key(8)] public FastDictionary<FinanceTransaction> FinanceTransactions { get; set; }
+        [Key(8)] public FastDictionary<int, FinanceTransaction> FinanceTransactions { get; }
 
-        public User(int id, string name, string address, string btcAddress, string ltcAddress, double btcAmount, double ltcAmount, FastList<FinanceTransaction> financeTransactions)
+        public User(int id, string name, string address, string btcAddress, string ltcAddress, double btcAmount, double ltcAmount, FastDictionary<int, FinanceTransaction> financeTransactions)
         {
             Id = id;
             Name = name;
@@ -41,11 +41,11 @@ namespace BlueWest.Data
 
         public void AddTransaction(FinanceTransaction financeTransaction)
         {
-            FinanceTransactions.Add(financeTransaction);
+            FinanceTransactions.Add(FinanceTransactions.Count + 1, financeTransaction);
         }
         public void AddTransaction(FinanceTransactionInsertDto financeTransaction)
         {
-            FinanceTransactions.Add(new FinanceTransaction(financeTransaction));
+            FinanceTransactions.Add(FinanceTransactions.Count + 1, new FinanceTransaction(financeTransaction, FinanceTransactions.Count + 1));
         }
 
         internal bool HasTransaction(int transactionId)
@@ -53,9 +53,9 @@ namespace BlueWest.Data
             return FinanceTransactions.Contains(transactionId);
         }
 
-        internal Transaction GetTransactionById(int transactionId)
+        internal FinanceTransaction GetTransactionById(int transactionId)
         {
-            return FinanceTransactions(transactionId);
+            return FinanceTransactions[transactionId];
         }
     }
 }
diff --git a/BlueWest.Data/UserList.cs b/BlueWest.Data/UserList.cs
index a6c9730..48ff02b 100644
--- a/BlueWest.Data/UserList.cs
+++ b/BlueWest.Data/UserList.cs
@@ -11,7 +11,7 @@ namespace BlueWest.Data
     {
         [Key(9)] public readonly FastDictionary<int, User> Users;
 
-        public int Length = 0;
+        [IgnoreMember] public int Length = 0;
 
         public UserList(FastDictionary<int, User> users)
         {
@@ -30,13 +30,13 @@ namespace BlueWest.Data
             return -1;
         }
 
-        internal DataQueryResult GetUserById(int id)
+        public DataQueryResult<User> GetUserById(int id)
         {
-            if (Users.ContainsKey(id)) return new PositiveResult<User>(Users[id]);
-            return new NegativeResult("Can't find a user with the provided id.");
+            if (Users.ContainsKey(id)) return new DataQueryResult<User>(Users[id], true);
+            return new DataQueryResult<User>(null, false, "Can't find a user with the provided id.");
         }
 
-        internal bool RemoveUser(int userId)
+        public bool RemoveUser(int userId)
         {
             if (Users.ContainsKey(userId))
             {
@@ -52,25 +52,30 @@ namespace BlueWest.Data
             return Users.Contains(userId);
         }
 
-        internal DataQueryResult UpdateUser(int userId, UserUpdateDto userUpdate)
+        public DataQueryResult<User> UpdateUser(int userId, UserUpdateDto userUpdate)
         {
-            Users[userId].Update(userUpdate);
-            return Users[userId];
+            if (Users.ContainsKey(userId))
+            {
+                Users[userId].Update(userUpdate);
+                return new DataQueryResult<User>(Users[userId], true);
+            }
+            
+            return new DataQueryResult<User>(null, false);
         }
 
 
         internal bool UserHasTransaction(int userId, int transactionId) => HasUser(userId) && Users[userId].FinanceTransactions.Contains(transactionId);
 
-        internal DataQueryResult GetTransactionById(int userId, int transactionId)
+        public DataQueryResult<FinanceTransaction> GetTransactionById(int userId, int transactionId)
         {
-            if(!HasUser(userId)) return new NegativeResult("Can't find a user with the provided id.");
+            if(!HasUser(userId)) return new DataQueryResult<FinanceTransaction>(new FinanceTransaction(), false, "Can't find a user with the provided id.");
 
-            if (UserHasTransaction(userId, transactionId)) return new PositiveResult<Transaction>(Users[userId].FinanceTransactions[transactionId]);
+            if (UserHasTransaction(userId, transactionId)) return new DataQueryResult<FinanceTransaction>(Users[userId].FinanceTransactions[transactionId]);
 
-            return new NegativeResult("No transaction was found with the specified id");
+            return new DataQueryResult<FinanceTransaction>(new FinanceTransaction(), false, "Can't find a transaction with the provided id.");
         }
 
-        internal User AddUser(int userId, UserUpdateDto userUpdateDto)
+        public User AddUser(int userId, UserUpdateDto userUpdateDto)
         {
             if (Users.ContainsKey(userId))
             {
@@ -80,7 +85,7 @@ namespace BlueWest.Data
             
             var id = userId != -1 ? userId : Length + 1;
 
-            var newUser = new User(userUpdateDto, id, new FastList<FinanceTransaction>());
+            var newUser = new User(userUpdateDto);
 
             Users.Add(Length, newUser);
 
@@ -91,28 +96,28 @@ namespace BlueWest.Data
 
         const string NoIdError = "No transaction was found with the specified id";
 
-        static NegativeResult NoIdResult = new NegativeResult(NoIdError);
-        internal  DataQueryResult AddFinanceTransaction(int userId, FinanceTransactionInsertDto financeTransactionDto)
+        public DataQueryResult<FinanceTransaction> AddFinanceTransaction(int userId, FinanceTransactionInsertDto financeTransactionDto)
         {
             if (Users.ContainsKey(userId))
             {
-                var financeTransaction = new FinanceTransaction(financeTransactionDto);
+                var financeTransaction = new FinanceTransaction(financeTransactionDto, Users[userId].FinanceTransactions.Count + 1);
                 Users[userId].AddTransaction(financeTransaction);
-                return new PositiveResult<BlueWest.Data.FinanceTransaction>(financeTransaction);
+                return new DataQueryResult<FinanceTransaction>(financeTransaction);
             }
 
-            return NoIdResult;
+            return new DataQueryResult<FinanceTransaction>(new FinanceTransaction(), false,
+                "no transaction with the provided id");
         }
 
 
-        internal FastList<FinanceTransaction> GetUserTransactions(int userId)
+        public ImmutableArray<FinanceTransaction> GetUserTransactions(int userId)
         {
             if (Users.ContainsKey(userId))
             {
-                return Users[userId].FinanceTransactions;
+                return Users[userId].FinanceTransactions.Values.ToImmutableArray();
             }
 
-            return new FastList<FinanceTransaction>();
+            return new ImmutableArray<FinanceTransaction>();
         }
 
     }
diff --git a/BlueWest.WebApi/BlueWest.WebApi.csproj b/BlueWest.WebApi/BlueWest.WebApi.csproj
index 6383267..efd5660 100644
--- a/BlueWest.WebApi/BlueWest.WebApi.csproj
+++ b/BlueWest.WebApi/BlueWest.WebApi.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
-    <TargetFramework>net5.0-windows</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <LangVersion>10</LangVersion>
   </PropertyGroup>
 
diff --git a/BlueWest.WebApi/Controllers/UserController.cs b/BlueWest.WebApi/Controllers/UserController.cs
index 5eef681..35e9741 100644
--- a/BlueWest.WebApi/Controllers/UserController.cs
+++ b/BlueWest.WebApi/Controllers/UserController.cs
@@ -1,4 +1,5 @@
-using BlueWest.Core.Tests;
+using System.Collections.Immutable;
+using BlueWest.Collections;
 using BlueWest.Data;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc;
@@ -18,7 +19,7 @@ namespace BlueWest.WebApi.Controllers
         {
             if (_userList != null)
             {
-                return Ok(_userList);
+                return Ok(_userList.Users.Values.ToImmutableArray());
 
             }
 
@@ -31,9 +32,9 @@ namespace BlueWest.WebApi.Controllers
         [HttpGet("{userId}", Name = nameof(GetUserById))]
         public ActionResult GetUserById(int userId)
         {
-            User? user = MemoryData.GetUserById(userId);
+            DataQueryResult<User> user = MemoryData.GetUserById(userId);
             
-            if (user != null)
+            if (user.HasValue)
             {
                 return Ok(user.Value);
 
@@ -49,7 +50,7 @@ namespace BlueWest.WebApi.Controllers
         public ActionResult GetTransactions(int userId)
         {
             var transactions = MemoryData.GetUserTransactions(userId);
-            return OK(transactions.ToDictionary());
+            return Ok(transactions);
         }
                        
         
@@ -60,9 +61,11 @@ namespace BlueWest.WebApi.Controllers
         {
             var user = MemoryData.UserList.GetUserById(userId);
            
-            var transactions = user?.FinanceTransactions;
+            if(!user.HasValue) return new NotFoundResult();
+
+            var transactions = user?.Value.FinanceTransactions;
             
-            FinanceTransaction? transaction = transactions?.FirstOrNull(t => t.Id == transactionId);
+            FinanceTransaction? transaction = transactions?.Values.ToImmutableArray().FirstOrNull(t => t.Id == transactionId);
                 
             if (transaction != null)
             {
@@ -113,9 +116,9 @@ namespace BlueWest.WebApi.Controllers
         [HttpPost("{userId}/transactions")]
         public ActionResult PostTransaction(int userId, FinanceTransactionInsertDto financeTransaction)
         {
-            FinanceTransaction? result = MemoryData.UserList.AddFinanceTransaction(userId, financeTransaction);
+            DataQueryResult<FinanceTransaction> result = MemoryData.UserList.AddFinanceTransaction(userId, financeTransaction);
 
-            if(result != null) return Ok(result);
+            if(result.HasValue) return Ok(result.Value);
 
             return new BadRequestResult();
         }
diff --git a/BlueWest/BlueWest.csproj b/BlueWest/BlueWest.csproj
index d79aeea..010b6bf 100644
--- a/BlueWest/BlueWest.csproj
+++ b/BlueWest/BlueWest.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <TargetFramework>net5.0</TargetFramework>
+        <TargetFramework>net6.0</TargetFramework>
         <Nullable>enable</Nullable>
         <ImplicitUsings>disable</ImplicitUsings>
         <RootNamespace>PerformanceSolution</RootNamespace>
diff --git a/BlueWest/Core/Tests/MappingExtensions.cs b/BlueWest/Core/Tests/MappingExtensions.cs
index 961a488..57cac46 100644
--- a/BlueWest/Core/Tests/MappingExtensions.cs
+++ b/BlueWest/Core/Tests/MappingExtensions.cs
@@ -3,7 +3,6 @@ using System.Collections.Generic;
 using System.ComponentModel;
 using System.Dynamic;
 using System.Linq;
-using BlueWest.Core.Tests;
 using BlueWest.DataAgent;
 
 namespace BlueWest.Core
diff --git a/BlueWest/Core/Tests/PocoDictionary.cs b/BlueWest/Core/Tests/PocoDictionary.cs
index 41055e6..5f28270 100644
--- a/BlueWest/Core/Tests/PocoDictionary.cs
+++ b/BlueWest/Core/Tests/PocoDictionary.cs
@@ -1,44 +1 @@
-using System;
-using System.Collections.Concurrent;
-using System.Collections.Generic;
-using System.Linq;
-using System.Linq.Expressions;
-using System.Reflection;
-
-namespace BlueWest.Core.Tests
-{
-   public static class PocoToDictionary
-{
-    private static readonly MethodInfo AddToDicitonaryMethod = typeof(IDictionary<string, object>).GetMethod("Add");
-    private static readonly ConcurrentDictionary<Type, Func<object, IDictionary<string, object>>> Converters = new ConcurrentDictionary<Type, Func<object, IDictionary<string, object>>>();
-    private static readonly ConstructorInfo DictionaryConstructor = typeof(Dictionary<string, object>).GetConstructors().FirstOrDefault(c => c.IsPublic && !c.GetParameters().Any());
- 
-    public static IDictionary<int, object> ToDictionary(this object obj) => obj == null ? null : Converters.GetOrAdd(obj.GetType(), o =>
-    {
-        var outputType = typeof(IDictionary<int, object>);
-        var inputType = obj.GetType();
-        var inputExpression = Expression.Parameter(typeof(object), "input");
-        var typedInputExpression = Expression.Convert(inputExpression, inputType);
-        var outputVariable = Expression.Variable(outputType, "output");
-        var returnTarget = Expression.Label(outputType);
-        var body = new List<Expression>
-        {
-            Expression.Assign(outputVariable, Expression.New(DictionaryConstructor))
-        };
-        body.AddRange(
-            from prop in inputType.GetProperties(BindingFlags.Instance | BindingFlags.Public | BindingFlags.FlattenHierarchy)
-            where prop.CanRead && (prop.PropertyType.IsPrimitive || prop.PropertyType == typeof(int))
-            let getExpression = Expression.Property(typedInputExpression, prop.GetMethod)
-            let convertExpression = Expression.Convert(getExpression, typeof(object))
-            select Expression.Call(outputVariable, AddToDicitonaryMethod, Expression.Constant(prop.Name), convertExpression));
-        body.Add(Expression.Return(returnTarget, outputVariable));
-        body.Add(Expression.Label(returnTarget, Expression.Constant(null, outputType)));
- 
-        var lambdaExpression = Expression.Lambda<Func<object, IDictionary<int, object>>>(
-            Expression.Block(new[] { outputVariable }, body),
-            inputExpression);
- 
-        return lambdaExpression.Compile();
-    })(obj);
-}
-}
\ No newline at end of file
+
\ No newline at end of file
diff --git a/BlueWest/Data/MemoryData.cs b/BlueWest/Data/MemoryData.cs
index 15450a7..2a05ad3 100644
--- a/BlueWest/Data/MemoryData.cs
+++ b/BlueWest/Data/MemoryData.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.Transactions;
 using BlueWest.Collections;
 using BlueWest.Data;
@@ -20,16 +21,16 @@ namespace PerformanceSolution.Data
             if (DEBUG)
             {
                 UserList = GenerateMockData();
-                SaveUserList();
+                //SaveUserList();
             }
             
-            LoadUsers();
+            //LoadUsers();
         }
 
         public static void SaveUserList(UserList userList)
         {
-            UserList = userList;
-            SaveLoadManager.Save(UserList, SavePathName);
+            //UserList = userList;
+            //SaveLoadManager.Save(UserList, SavePathName);
         }
 
         public static void LoadUsers()
@@ -38,7 +39,7 @@ namespace PerformanceSolution.Data
             UserList ??= new UserList(new FastDictionary<int, User>());
         }
 
-        public static Transaction GetTransactionById(int userId, int transactionId) => UserList.GetTransactionById(userId, transactionId);
+        public static DataQueryResult<FinanceTransaction> GetTransactionById(int userId, int transactionId) => UserList.GetTransactionById(userId, transactionId);
 
 
         private static void SaveUserList() => SaveUserList(UserList);
@@ -53,10 +54,10 @@ namespace PerformanceSolution.Data
         {
 
             
-            var transactions = new FastList<FinanceTransaction>();
+            var transactions = new FastDictionary<int, FinanceTransaction>();
             var financeTransaction = new FinanceTransaction(0, 1, FinanceTransactionType.Buy, FinanceSymbol.BTC_EUR, 0,
                 0, 0.1, DateTime.Now);
-            transactions.Add(financeTransaction);
+            transactions.Add(1, financeTransaction);
 
             var u = new User(1, "Rui Sousa", "Sagres", "NOADD", "NOADD", 0, 0, transactions);
             var list = new FastDictionary<int, User>(10);
@@ -65,12 +66,12 @@ namespace PerformanceSolution.Data
             return new UserList(list);
         }
 
-        public static User? GetUserById(int userId)
+        public static DataQueryResult<User> GetUserById(int userId)
         {
             return UserList.GetUserById(userId);
         }
         
-        public static FastList<FinanceTransaction> GetUserTransactions(int userId)
+        public static ImmutableArray<FinanceTransaction> GetUserTransactions(int userId)
         {
             return UserList.GetUserTransactions(userId);
         }
diff --git a/MapTo b/MapTo
index 9470afb..ffc3dc7 160000
--- a/MapTo
+++ b/MapTo
@@ -1 +1 @@
-Subproject commit 9470afb737d873f2fbbc631813eadf10032c5c6b
+Subproject commit ffc3dc7729c97190849441d73edb2dfc5fe63ecd