diff --git a/src/hackerrank/certification/num_cells.py b/src/hackerrank/certification/num_cells.py
index 27533255..a8168e89 100644
--- a/src/hackerrank/certification/num_cells.py
+++ b/src/hackerrank/certification/num_cells.py
@@ -7,16 +7,16 @@
 LOGGER = logging.getLogger(__name__)
 
 
-def valid_coordinate(grid: List[List[int]], i: int, j: int, k: int, m: int) -> bool:
+def validCoordinate(grid: List[List[int]], i: int, j: int, k: int, m: int) -> bool:
     return 0 <= k < len(grid) and \
         0 <= m < len(grid[k]) and \
         (k, m) != (i, j)
 
 
-def all_neighbors_are_minor(grid: List[List[int]], i: int, j: int) -> bool:
+def allNeighborsAreMinor(grid: List[List[int]], i: int, j: int) -> bool:
     for k in range(i - 1, i + 2):
         for m in range(j - 1, j + 2):
-            if valid_coordinate(grid, i, j, k, m) and \
+            if validCoordinate(grid, i, j, k, m) and \
                     grid[k][m] >= grid[i][j]:
                 LOGGER.debug(
                     'Found some major neighbor: i = %i, j = %i, grid[i][j] = %i',
@@ -29,7 +29,7 @@ def all_neighbors_are_minor(grid: List[List[int]], i: int, j: int) -> bool:
     return False
 
 
-def num_cells(grid: List[List[int]]) -> int:
+def numCells(grid: List[List[int]]) -> int:
 
     dominant_counter = 0
 
@@ -37,7 +37,7 @@ def num_cells(grid: List[List[int]]) -> int:
         for j in range(0, len(grid[i])):
             LOGGER.debug('Checking: i = %i, j = %i, grid[i][j] = %i', i, j, grid[i][j])
 
-            if all_neighbors_are_minor(grid, i, j) is False:
+            if allNeighborsAreMinor(grid, i, j) is False:
                 LOGGER.debug('grid[%i][%i] is dominant', i, j)
                 dominant_counter += 1
 
diff --git a/src/hackerrank/certification/num_cells_test.py b/src/hackerrank/certification/num_cells_test.py
index 65809d19..642c9bed 100644
--- a/src/hackerrank/certification/num_cells_test.py
+++ b/src/hackerrank/certification/num_cells_test.py
@@ -1,5 +1,5 @@
 import unittest
-from .num_cells import num_cells
+from .num_cells import numCells
 
 
 class TestNumCells(unittest.TestCase):
@@ -14,6 +14,6 @@ def test_num_cells_case_0(self):
         solution_found = 2
 
         self.assertEqual(
-            num_cells(grid), solution_found,
+            numCells(grid), solution_found,
             f"num_cells({grid}) must be "
             f"=> {solution_found}")
diff --git a/src/hackerrank/projecteuler/euler001.py b/src/hackerrank/projecteuler/euler001.py
index 8520a570..89ae3188 100644
--- a/src/hackerrank/projecteuler/euler001.py
+++ b/src/hackerrank/projecteuler/euler001.py
@@ -5,7 +5,7 @@
 
 
 # Function to find sum of Arithmetic Progression series
-def sum_of_arithmetic_progression(n: int, d: int) -> int:
+def sumOfArithmeticProgression(n: int, d: int) -> int:
 
     # Number of terms
     n = n // d
@@ -20,6 +20,6 @@ def euler001(a: int, b: int, n: int) -> int:
     n = n - 1
     lcm = (a * b) // math.gcd(a, b)
 
-    return sum_of_arithmetic_progression(n, a) + \
-        sum_of_arithmetic_progression(n, b) - \
-        sum_of_arithmetic_progression(n, lcm)
+    return sumOfArithmeticProgression(n, a) + \
+        sumOfArithmeticProgression(n, b) - \
+        sumOfArithmeticProgression(n, lcm)
diff --git a/src/hackerrank/projecteuler/euler002.py b/src/hackerrank/projecteuler/euler002.py
index 16ccfc51..4fbb9833 100644
--- a/src/hackerrank/projecteuler/euler002.py
+++ b/src/hackerrank/projecteuler/euler002.py
@@ -1,7 +1,7 @@
 # @link Problem definition [[docs/hackerrank/projecteuler/euler002.md]]
 # pylint: disable=C0103:invalid-name
 
-def fibo_even_sum(n: int) -> int:
+def fiboEvenSum(n: int) -> int:
     total = 0
     fibo = 0
     fibo1 = 1
@@ -20,4 +20,4 @@ def fibo_even_sum(n: int) -> int:
 
 def euler002(n: int) -> int:
 
-    return fibo_even_sum(n)
+    return fiboEvenSum(n)
diff --git a/src/hackerrank/projecteuler/euler003.py b/src/hackerrank/projecteuler/euler003.py
index 8f231c67..37435646 100644
--- a/src/hackerrank/projecteuler/euler003.py
+++ b/src/hackerrank/projecteuler/euler003.py
@@ -6,7 +6,7 @@
 import math
 
 
-def prime_factor(n: int) -> 'int | None':
+def primeFactor(n: int) -> 'int | None':
 
     if n < 2:
         return None
@@ -30,4 +30,4 @@ def prime_factor(n: int) -> 'int | None':
 
 def euler003(n: int) -> 'int | None':
 
-    return prime_factor(n)
+    return primeFactor(n)