diff --git a/src/services/helpers.ts b/src/services/helpers.ts
index df67a4c..c4a3292 100644
--- a/src/services/helpers.ts
+++ b/src/services/helpers.ts
@@ -6,38 +6,43 @@ import {
   replaceElementOfArray,
 } from '@services/utils'
 
-function reorderCardsOnColumn(column: any, reorderCards: any) {
+function reorderCardsOnColumn<TCard extends Card>(column: Column<TCard>, reorderCards: (cards: TCard[]) => TCard[]): Column<TCard> {
   return { ...column, cards: reorderCards(column.cards) }
 }
 
-function moveColumn(board: any, { fromPosition }: any, { toPosition }: any) {
+function moveColumn<TCard extends Card>(board: KanbanBoard<TCard>, fromPosition: number, toPosition: number): KanbanBoard<TCard> {
   return { ...board, columns: changeElementOfPositionInArray(board.columns, fromPosition, toPosition) }
 }
 
-function moveCard(board: any, { fromPosition, fromColumnId }: any, { toPosition, toColumnId }: any) {
-  const sourceColumn = board.columns.find((column: any) => column.id === fromColumnId)
-  const destinationColumn = board.columns.find((column: any) => column.id === toColumnId)
+function moveCard<TCard extends Card>(
+  board: KanbanBoard<TCard>,
+  fromPosition: number,
+  fromColumnId: string,
+  toPosition: number,
+  toColumnId: string
+): KanbanBoard<TCard> {
+  const sourceColumn = board.columns.find((column) => column.id === fromColumnId)
+  const destinationColumn = board.columns.find((column) => column.id === toColumnId)
+
+  if (!sourceColumn || !destinationColumn) {
+    throw new Error('Source or destination column not found')
+  }
 
-  const reorderColumnsOnBoard = (reorderColumnsMapper: any) => ({
+  const reorderColumnsOnBoard = (reorderColumnsMapper: (column: Column<TCard>) => Column<TCard>) => ({
     ...board,
     columns: board.columns.map(reorderColumnsMapper),
   })
+
   const reorderCardsOnSourceColumn = reorderCardsOnColumn.bind(null, sourceColumn)
   const reorderCardsOnDestinationColumn = reorderCardsOnColumn.bind(null, destinationColumn)
 
   if (sourceColumn.id === destinationColumn.id) {
-    const reorderedCardsOnColumn = reorderCardsOnSourceColumn((cards: any) => {
-      return changeElementOfPositionInArray(cards, fromPosition, toPosition)
-    })
-    return reorderColumnsOnBoard((column: any) => (column.id === sourceColumn.id ? reorderedCardsOnColumn : column))
+    const reorderedCardsOnColumn = reorderCardsOnSourceColumn((cards) => changeElementOfPositionInArray(cards, fromPosition, toPosition))
+    return reorderColumnsOnBoard((column) => (column.id === sourceColumn.id ? reorderedCardsOnColumn : column))
   } else {
-    const reorderedCardsOnSourceColumn = reorderCardsOnSourceColumn((cards: any) => {
-      return removeFromArrayAtPosition(cards, fromPosition)
-    })
-    const reorderedCardsOnDestinationColumn = reorderCardsOnDestinationColumn((cards: any) => {
-      return addInArrayAtPosition(cards, sourceColumn.cards[fromPosition], toPosition)
-    })
-    return reorderColumnsOnBoard((column: any) => {
+    const reorderedCardsOnSourceColumn = reorderCardsOnSourceColumn((cards) => removeFromArrayAtPosition(cards, fromPosition))
+    const reorderedCardsOnDestinationColumn = reorderCardsOnDestinationColumn((cards) => addInArrayAtPosition(cards, sourceColumn.cards[fromPosition], toPosition))
+    return reorderColumnsOnBoard((column) => {
       if (column.id === sourceColumn.id) return reorderedCardsOnSourceColumn
       if (column.id === destinationColumn.id) return reorderedCardsOnDestinationColumn
       return column
@@ -45,22 +50,18 @@ function moveCard(board: any, { fromPosition, fromColumnId }: any, { toPosition,
   }
 }
 
-function addColumn<TCard extends Card>(board: KanbanBoard<TCard>, column: Partial<Column<TCard>>) {
-  return { ...board, columns: addInArrayAtPosition(board.columns, column, board.columns.length) }
+function addColumn<TCard extends Card>(board: KanbanBoard<TCard>, column: Partial<Column<TCard>>): KanbanBoard<TCard> {
+  return { ...board, columns: addInArrayAtPosition(board.columns, column as Column<TCard>, board.columns.length) }
 }
 
-function removeColumn<TCard extends Card>(board: KanbanBoard<TCard>, column: Column<TCard>) {
-  return { ...board, columns: board.columns.filter(({ id }: any) => id !== column.id) }
+function removeColumn<TCard extends Card>(board: KanbanBoard<TCard>, column: Column<TCard>): KanbanBoard<TCard> {
+  return { ...board, columns: board.columns.filter(({ id }) => id !== column.id) }
 }
 
-function changeColumn<TCard extends Card>(
-  board: KanbanBoard<TCard>,
-  column: Column<TCard>,
-  newColumn: Partial<Column<TCard>>
-) {
+function changeColumn<TCard extends Card>(board: KanbanBoard<TCard>, column: Column<TCard>, newColumn: Partial<Column<TCard>>): KanbanBoard<TCard> {
   const changedColumns = replaceElementOfArray(board.columns)({
-    when: ({ id }: any) => id === column.id,
-    for: (value: any) => ({
+    when: ({ id }) => id === column.id,
+    for: (value) => ({
       ...value,
       ...newColumn,
     }),
@@ -68,18 +69,13 @@ function changeColumn<TCard extends Card>(
   return { ...board, columns: changedColumns }
 }
 
-function addCard<TCard extends Card>(
-  board: KanbanBoard<TCard>,
-  inColumn: any,
-  card: TCard,
-  { on }: any = {}
-): KanbanBoard<TCard> {
-  const columnToAdd = board.columns.find(({ id }: any) => id === inColumn.id)
+function addCard<TCard extends Card>(board: KanbanBoard<TCard>, inColumn: Column<TCard>, card: TCard, { on }: { on?: 'top' | 'bottom' } = {}): KanbanBoard<TCard> {
+  const columnToAdd = board.columns.find(({ id }) => id === inColumn.id)
   if (!columnToAdd) throw new Error(`Cannot find column with ID: ${inColumn.id}`)
   const cards = addInArrayAtPosition(columnToAdd.cards, card, on === 'top' ? 0 : columnToAdd.cards.length)
   const columns = replaceElementOfArray(board.columns)({
-    when: ({ id }: any) => inColumn.id === id,
-    for: (value: any) => ({
+    when: ({ id }) => inColumn.id === id,
+    for: (value) => ({
       ...value,
       cards,
     }),
@@ -87,19 +83,20 @@ function addCard<TCard extends Card>(
   return { ...board, columns }
 }
 
-function removeCard<TCard extends Card>(board: any, fromColumn: any, card: any): KanbanBoard<TCard> {
-  const columnToRemove = board.columns.find(({ id }: any) => id === fromColumn.id)
-  const filteredCards = columnToRemove.cards.filter(({ id }: any) => card.id !== id)
+function removeCard<TCard extends Card>(board: KanbanBoard<TCard>, fromColumn: Column<TCard>, card: TCard): KanbanBoard<TCard> {
+  const columnToRemove = board.columns.find(({ id }) => id === fromColumn.id)
+  if (!columnToRemove) throw new Error(`Cannot find column with ID: ${fromColumn.id}`)
+  const filteredCards = columnToRemove.cards.filter(({ id }) => card.id !== id)
   const columnWithoutCard = { ...columnToRemove, cards: filteredCards }
-  const filteredColumns = board.columns.map((column: any) => (fromColumn.id === column.id ? columnWithoutCard : column))
+  const filteredColumns = board.columns.map((column) => (fromColumn.id === column.id ? columnWithoutCard : column))
   return { ...board, columns: filteredColumns }
 }
 
-function changeCard(board: any, cardId: any, newCard: any) {
-  const changedCards = (cards: any) =>
+function changeCard<TCard extends Card>(board: KanbanBoard<TCard>, cardId: string, newCard: Partial<TCard>): KanbanBoard<TCard> {
+  const changedCards = (cards: TCard[]) =>
     replaceElementOfArray(cards)({
-      when: ({ id }: any) => id === cardId,
-      for: (card: any) => ({
+      when: ({ id }) => id === cardId,
+      for: (card) => ({
         ...card,
         ...newCard,
       }),
@@ -107,7 +104,7 @@ function changeCard(board: any, cardId: any, newCard: any) {
 
   return {
     ...board,
-    columns: board.columns.map((column: any) => ({
+    columns: board.columns.map((column) => ({
       ...column,
       cards: changedCards(column.cards),
     })),