diff --git a/barker/barker/models/inventory.py b/barker/barker/models/inventory.py
index ae88faa..a3697b2 100644
--- a/barker/barker/models/inventory.py
+++ b/barker/barker/models/inventory.py
@@ -6,6 +6,7 @@ from typing import TYPE_CHECKING, List
 from barker.models.product import Product
 from sqlalchemy import (
     Boolean,
+    ColumnElement,
     ForeignKey,
     Integer,
     Numeric,
@@ -13,6 +14,7 @@ from sqlalchemy import (
     case,
     func,
     text,
+    type_coerce,
 )
 from sqlalchemy.dialects.postgresql import UUID
 from sqlalchemy.ext.hybrid import hybrid_property
@@ -86,37 +88,44 @@ class Inventory:
             self.tax = tax
 
     @hybrid_property
-    def effective_price(self):
+    def effective_price(self) -> Decimal:
         return 0 if self.is_happy_hour else self.price
 
     @effective_price.inplace.expression
     @classmethod
-    def _effective_price_expression(cls):
-        return case((cls.is_happy_hour == True, 0), else_=cls.price)  # noqa: E712
+    def _effective_price_expression(cls) -> ColumnElement[Decimal]:
+        return type_coerce(
+            case((cls.is_happy_hour == True, 0), else_=cls.price), Numeric(precision=15, scale=2)  # noqa: E712
+        ).label("effective_price")
 
     @hybrid_property
-    def net(self):
+    def net(self) -> Decimal:
         return self.effective_price * self.quantity * (1 - self.discount)
 
     @net.inplace.expression
     @classmethod
-    def _net_expression(cls):
-        return cls.effective_price * cls.quantity * (1 - cls.discount)
+    def _net_expression(cls) -> ColumnElement[Decimal]:
+        return type_coerce(
+            cls.effective_price * cls.quantity * (1 - cls.discount), Numeric(precision=15, scale=2)
+        ).label("net")
 
     @hybrid_property
-    def tax_amount(self):
+    def tax_amount(self) -> Decimal:
         return self.net * self.tax_rate
 
     @tax_amount.inplace.expression
     @classmethod
-    def _tax_amount_expression(cls):
-        return cls.net * cls.tax_rate
+    def _tax_amount_expression(cls) -> ColumnElement[Decimal]:
+        return type_coerce(cls.net * cls.tax_rate, Numeric(precision=15, scale=2)).label("tax_amount")
 
     @hybrid_property
-    def amount(self):
+    def amount(self) -> Decimal:
         return round(Decimal(self.net * (1 + self.tax_rate)), 2)
 
     @amount.inplace.expression
     @classmethod
-    def _amount_expression(cls):
-        return func.round(cls.net * (1 + cls.tax_rate), 2)
+    def _amount_expression(cls) -> ColumnElement[Decimal]:
+        # func.round(cls.net * (1 + cls.tax_rate), 2)
+        return type_coerce(
+            func.round(cls.net * (1 + cls.tax_rate) / 0.02, 0) * 0.02, Numeric(precision=15, scale=2)
+        ).label("amount")
diff --git a/barker/barker/models/user.py b/barker/barker/models/user.py
index c2de9b6..80f1da1 100644
--- a/barker/barker/models/user.py
+++ b/barker/barker/models/user.py
@@ -39,8 +39,8 @@ class User:
         return self._password
 
     @password.inplace.setter
-    def _password_setter(self, password):
-        self._password = encrypt(password)
+    def _password_setter(self, value: str) -> None:
+        self._password = encrypt(value)
 
     def __init__(self, name=None, password=None, locked_out=None, id_=None):
         self.name = name
diff --git a/barker/barker/schemas/master.py b/barker/barker/schemas/master.py
index 8944920..766d9b7 100644
--- a/barker/barker/schemas/master.py
+++ b/barker/barker/schemas/master.py
@@ -1,9 +1,6 @@
 import uuid
 
-from datetime import date, datetime
-from decimal import Decimal
-
-from pydantic import BaseModel, ConfigDict, Field, field_validator, model_validator
+from pydantic import BaseModel, ConfigDict, Field
 
 from . import to_camel
 
@@ -26,43 +23,6 @@ class Account(AccountIn):
     is_fixture: bool
 
 
-class EmployeeIn(AccountBase):
-    designation: str
-    salary: int = Field(ge=0)
-    points: Decimal = Field(ge=0, lt=1000)
-    joining_date: date
-    leaving_date: date | None = None
-
-    @field_validator("joining_date", mode="before")
-    @classmethod
-    def parse_joining_date(cls, value):
-        return datetime.strptime(value, "%d-%b-%Y").date()
-
-    @field_validator("leaving_date", mode="before")
-    @classmethod
-    def parse_leaving_date(cls, value):
-        if value is None or value == "":
-            return None
-        else:
-            return datetime.strptime(value, "%d-%b-%Y").date()
-
-    @model_validator(mode="after")
-    def leaving_date_more_than_joining_date(self) -> "EmployeeIn":
-        if self.is_active:
-            self.leaving_date = None
-        if (not self.is_active) and (self.leaving_date is None):
-            raise ValueError("Need leaving date for employee")
-        if self.leaving_date < self.joining_date:
-            raise ValueError("Leaving Date cannot be less than Joining Date")
-        return self
-
-
-class Employee(EmployeeIn):
-    id_: uuid.UUID
-    code: int
-    is_fixture: bool
-
-
 class DbSetting(BaseModel):
     id_: uuid.UUID
     name: str
diff --git a/barker/barker/schemas/voucher.py b/barker/barker/schemas/voucher.py
index 9012bdb..07b9dff 100644
--- a/barker/barker/schemas/voucher.py
+++ b/barker/barker/schemas/voucher.py
@@ -2,7 +2,7 @@ import uuid
 
 from decimal import Decimal
 
-from pydantic import BaseModel, ConfigDict, Field, model_validator
+from pydantic import BaseModel, ConfigDict, Field, field_validator, model_validator
 
 from . import to_camel
 from .customer import CustomerLink
@@ -25,6 +25,34 @@ class Inventory(BaseModel):
     amount: Decimal | None = None
     model_config = ConfigDict(alias_generator=to_camel, populate_by_name=True)
 
+    @field_validator("quantity")
+    @classmethod
+    def _quantity(cls, value: Decimal | None) -> Decimal:
+        if value is None:
+            return Decimal(0)
+        return round(value, 2)
+
+    @field_validator("price")
+    @classmethod
+    def _price(cls, value: Decimal | None) -> Decimal:
+        if value is None:
+            return Decimal(0)
+        return round(value, 2)
+
+    @field_validator("tax_rate")
+    @classmethod
+    def _tax_rate(cls, value: Decimal | None) -> Decimal:
+        if value is None:
+            return Decimal(0)
+        return round(value, 5)
+
+    @field_validator("discount")
+    @classmethod
+    def _discount(cls, value: Decimal | None) -> Decimal:
+        if value is None:
+            return Decimal(0)
+        return round(value, 5)
+
     @model_validator(mode="after")
     def calculate_amount(self) -> "Inventory":
         self.amount = round(
diff --git a/barker/pyproject.toml b/barker/pyproject.toml
index 60af26a..df52c30 100644
--- a/barker/pyproject.toml
+++ b/barker/pyproject.toml
@@ -39,6 +39,11 @@ tomli = "^2.0.1"
 requires = ["poetry-core>=1.0.0"]
 build-backend = "poetry.core.masonry.api"
 
+[tool.ruff]
+line-length = 120
+# Assume Python 3.11.
+target-version = "py311"
+
 [tool.isort]
 profile = "black"
 atomic = true