diff --git a/CodingInterviews/readme.md b/CodingInterviews/readme.md
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+# Coding Interviews
+
+Algorithms, data structures, Leetcode style problems and just coding-interview style katas.
+
+
+## To Do
+
+### **1. Dynamic Array**
+
+```go
+// Basic CRUD + utility operations
+func (a *MyDynamicArray[T]) Add(val T)                  // append at end
+func (a *MyDynamicArray[T]) Insert(index int, val T)    // insert at specific index
+func (a *MyDynamicArray[T]) Remove(index int) T         // remove element at index
+func (a *MyDynamicArray[T]) Get(index int) T
+func (a *MyDynamicArray[T]) Set(index int, val T)
+func (a *MyDynamicArray[T]) Size() int
+func (a *MyDynamicArray[T]) Capacity() int
+func (a *MyDynamicArray[T]) Clear()
+func (a *MyDynamicArray[T]) Contains(val T) bool
+func (a *MyDynamicArray[T]) IndexOf(val T) int
+func (a *MyDynamicArray[T]) ToSlice() []T
+```
+
+---
+
+### **2. Stack**
+
+```go
+func (s *Stack[T]) Push(val T)
+func (s *Stack[T]) Pop() T
+func (s *Stack[T]) Peek() T
+func (s *Stack[T]) IsEmpty() bool
+func (s *Stack[T]) Size() int
+func (s *Stack[T]) Clear()
+```
+
+---
+
+### **3. Queue**
+
+```go
+func (q *Queue[T]) Enqueue(val T)
+func (q *Queue[T]) Dequeue() T
+func (q *Queue[T]) Peek() T
+func (q *Queue[T]) IsEmpty() bool
+func (q *Queue[T]) Size() int
+func (q *Queue[T]) Clear()
+```
+
+---
+
+### **4. Deque (Double-Ended Queue)**
+
+```go
+func (d *Deque[T]) AddFront(val T)
+func (d *Deque[T]) AddBack(val T)
+func (d *Deque[T]) RemoveFront() T
+func (d *Deque[T]) RemoveBack() T
+func (d *Deque[T]) PeekFront() T
+func (d *Deque[T]) PeekBack() T
+func (d *Deque[T]) IsEmpty() bool
+func (d *Deque[T]) Size() int
+func (d *Deque[T]) Clear()
+```
+
+---
+
+### **5. Linked List (Singly / Doubly)**
+
+```go
+func (l *LinkedList[T]) AddFront(val T)
+func (l *LinkedList[T]) AddBack(val T)
+func (l *LinkedList[T]) InsertAt(index int, val T)
+func (l *LinkedList[T]) RemoveAt(index int) T
+func (l *LinkedList[T]) RemoveVal(val T) bool
+func (l *LinkedList[T]) Get(index int) T
+func (l *LinkedList[T]) Set(index int, val T)
+func (l *LinkedList[T]) Size() int
+func (l *LinkedList[T]) IsEmpty() bool
+func (l *LinkedList[T]) Contains(val T) bool
+func (l *LinkedList[T]) ToSlice() []T
+```
+
+---
+
+### **6. Hash Map**
+
+```go
+func (m *HashMap[K, V]) Put(key K, val V)
+func (m *HashMap[K, V]) Get(key K) (V, bool)
+func (m *HashMap[K, V]) Remove(key K)
+func (m *HashMap[K, V]) ContainsKey(key K) bool
+func (m *HashMap[K, V]) Keys() []K
+func (m *HashMap[K, V]) Values() []V
+func (m *HashMap[K, V]) Size() int
+func (m *HashMap[K, V]) Clear()
+```
+
+---
+
+### **7. Set**
+
+```go
+func (s *Set[T]) Add(val T)
+func (s *Set[T]) Remove(val T)
+func (s *Set[T]) Contains(val T) bool
+func (s *Set[T]) Size() int
+func (s *Set[T]) Clear()
+func (s *Set[T]) Union(other *Set[T]) *Set[T]
+func (s *Set[T]) Intersection(other *Set[T]) *Set[T]
+func (s *Set[T]) Difference(other *Set[T]) *Set[T]
+```
+
+---
+
+### **8. Binary Tree**
+
+```go
+func (t *BinaryTree[T]) Insert(val T)
+func (t *BinaryTree[T]) Delete(val T)
+func (t *BinaryTree[T]) Find(val T) *TreeNode[T]
+func (t *BinaryTree[T]) Inorder() []T
+func (t *BinaryTree[T]) Preorder() []T
+func (t *BinaryTree[T]) Postorder() []T
+func (t *BinaryTree[T]) Size() int
+func (t *BinaryTree[T]) Height() int
+func (t *BinaryTree[T]) Clear()
+```
+
+---
+
+### **9. Binary Search Tree (BST)**
+
+```go
+func (bst *BST[T]) Insert(val T)
+func (bst *BST[T]) Delete(val T)
+func (bst *BST[T]) Find(val T) *TreeNode[T]
+func (bst *BST[T]) Min() T
+func (bst *BST[T]) Max() T
+func (bst *BST[T]) Inorder() []T
+func (bst *BST[T]) Predecessor(val T) *TreeNode[T]
+func (bst *BST[T]) Successor(val T) *TreeNode[T]
+func (bst *BST[T]) Size() int
+func (bst *BST[T]) Height() int
+func (bst *BST[T]) Clear()
+```
+
+---
+
+### **10. Heap (Min / Max)**
+
+```go
+func (h *Heap[T]) Insert(val T)
+func (h *Heap[T]) Extract() T        // Min or Max
+func (h *Heap[T]) Peek() T
+func (h *Heap[T]) Size() int
+func (h *Heap[T]) Clear()
+func (h *Heap[T]) Heapify()          // Optional: build heap from slice
+```
+
+---
+
+### **11. Graph (Adjacency List)**
+
+```go
+func (g *Graph[T]) AddVertex(v T)
+func (g *Graph[T]) RemoveVertex(v T)
+func (g *Graph[T]) AddEdge(u, v T)
+func (g *Graph[T]) RemoveEdge(u, v T)
+func (g *Graph[T]) Neighbors(v T) []T
+func (g *Graph[T]) BFS(start T) []T
+func (g *Graph[T]) DFS(start T) []T
+func (g *Graph[T]) HasPath(u, v T) bool
+func (g *Graph[T]) Clear()
+```
+
+---
+
+### **12. Trie**
+
+```go
+func (t *Trie) Insert(word string)
+func (t *Trie) Search(word string) bool
+func (t *Trie) StartsWith(prefix string) bool
+func (t *Trie) Delete(word string) bool
+func (t *Trie) Clear()
+```
+
+---
+
+### **13. Priority Queue**
+
+```go
+func (pq *PriorityQueue[T]) Insert(val T, priority int)
+func (pq *PriorityQueue[T]) Extract() (T, int)    // returns val + priority
+func (pq *PriorityQueue[T]) Peek() (T, int)
+func (pq *PriorityQueue[T]) Size() int
+func (pq *PriorityQueue[T]) Clear()
+```
+
+---
+
+
+### **14.  Array / Slice Operations**
+
+```go
+func MaxSlidingWindow(nums []int, k int) []int
+func MinSlidingWindow(nums []int, k int) []int
+func PrefixSum(nums []int) []int
+func BinarySearch(nums []int, target int) int
+func Kadane(nums []int) int                          // Max contiguous sum
+func Reverse(nums []int)
+func Rotate(nums []int, k int)
+func Partition(nums []int, pivot int)
+func MergeIntervals(intervals [][]int) [][]int
+func Subarrays(nums []int) [][]int
+func TwoPointersSum(nums []int, target int) (int,int)
+func CountFrequency(nums []int) map[int]int
+```
+
diff --git a/README.md b/README.md
index 1a22dea..2b43bf2 100644
--- a/README.md
+++ b/README.md
@@ -17,3 +17,9 @@ Each package may contain multiple versions where I experiment with different app
 - [tui/v2](./tui/v2/readme.md)
 - [todoapp/v1](./todoapp/v1/readme.md)
 - [fstree/v3](./fstree/v3/readme.md)
+
+
+## Ideas for later
+
+- [OAuth 2.0 Course for Beginners @ freeCodeCamp](https://www.youtube.com/watch?v=WSsOXo07LeE)
+  - Follow along but use GO wherever possible