diff --git a/.gitignore b/.gitignore
index 04eea848..9e078da1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,6 +10,10 @@ lib/
 # Rust build artifacts
 /target
 **/target
+**/Cargo.lock
+
+# Personal notes
+rust_session/student_registry_v2/notes/
 
 # Hardhat / Foundry build artifacts
 artifacts/
diff --git a/rust_session/Cargo.lock b/rust_session/Cargo.lock
deleted file mode 100644
index bf268c9a..00000000
--- a/rust_session/Cargo.lock
+++ /dev/null
@@ -1,7 +0,0 @@
-# This file is automatically @generated by Cargo.
-# It is not intended for manual editing.
-version = 4
-
-[[package]]
-name = "rust_session"
-version = "0.1.0"
diff --git a/rust_session/src/grade.rs b/rust_session/src/grade.rs
new file mode 100644
index 00000000..fbbfd838
--- /dev/null
+++ b/rust_session/src/grade.rs
@@ -0,0 +1,31 @@
+#[derive(Debug)]
+pub enum Grade {
+    First,
+    Second,
+    Third
+}
+
+impl Grade {
+    pub fn get_grade_points(&self) -> &str {
+        match self {
+            Grade::First => "Cohort 1",
+            Grade::Second => "Cohort 2",
+            Grade::Third => "Cohort 3",
+        }
+    }
+}
+
+#[derive(Debug)]
+pub enum Sex {
+    Male,
+    Female
+}
+
+impl Sex {
+    pub fn get_sex(&self) {
+        match self {
+            Sex::Male => println!("Male"),
+            Sex::Female => println!("Female"),
+        }
+    }
+}
\ No newline at end of file
diff --git a/rust_session/src/main.rs b/rust_session/src/main.rs
index c11cc20e..9dd41a56 100644
--- a/rust_session/src/main.rs
+++ b/rust_session/src/main.rs
@@ -1,17 +1,38 @@
-mod sub;
-mod sum;
-mod ownership;
-mod array;
-mod mut_ex;
-
+// mod sub;
+// mod sum;
+// mod ownership;
+// mod array;
+// mod mut_ex;
+// mod grade;
+// mod voters;
+// mod student_struct;
 
 fn main() {
     // use sub::sub;
+    // use crate::voters::{Age, EligibleVoters};
     // sub(10, 5);
     // ownership::test_ownership();
     // ownership::call_name();
     // array::test_array();
     // ownership::test_move();
     // ownership::call_greet();
-    mut_ex::test_mut();
+    // mut_ex::test_mut();
+    // grade::Grade::First.get_grade_points();
+    // grade::Grade::Second.get_grade_points();
+    // grade::Grade::Third.get_grade_points();
+    // grade::Sex::Male.get_sex();
+    // grade::Sex::Female.get_sex();
+    // voters::Age::SilverJubilee.get_age();
+    // voters::Age::GoldenJubilee.get_age();
+    // voters::Age::PlatinumJubilee.get_age();
+    // voters::Age::Centenarian.get_age();
+    // voters::EligibleVoters::Juvenile.get_eligible_voters();
+    // voters::EligibleVoters::Teenager.get_eligible_voters();
+    // voters::EligibleVoters::Adult.get_eligible_voters();
+
+    // let age = Age::SilverJubilee;
+    // let eligible_voters = EligibleVoters::Teenager;
+    // println!("Age: {}", age.get_age());
+    // println!("Eligible Voters: {}", eligible_voters.get_eligible_voters());
+
 }
diff --git a/rust_session/src/student_struct.rs b/rust_session/src/student_struct.rs
new file mode 100644
index 00000000..67ee21cd
--- /dev/null
+++ b/rust_session/src/student_struct.rs
@@ -0,0 +1,37 @@
+#[derive(Debug)]
+pub enum Status{
+    Pending,
+    Completed,
+    InProgress,
+    Cancelled,
+}
+
+impl Status {
+    pub fn get_status(&self) -> &str {
+        match self {
+            Status::Pending => "Pending",
+            Status::Completed => "Completed",
+            Status::InProgress => "InProgress",
+            Status::Cancelled => "Cancelled",
+        }
+    }
+}
+
+
+pub struct Todo {
+    pub id: u8,
+    pub title: String,
+    pub description: String,
+    pub status: Status,
+}
+
+impl Todo {
+    pub fn new(id: u8, title: String, description: String, status: Status) -> Todo {
+        Todo { 
+            id, 
+            title, 
+            description, 
+            status 
+        }
+    }
+}
\ No newline at end of file
diff --git a/rust_session/src/voters.rs b/rust_session/src/voters.rs
new file mode 100644
index 00000000..2d6a3918
--- /dev/null
+++ b/rust_session/src/voters.rs
@@ -0,0 +1,35 @@
+#[derive(Debug)]
+pub enum Age {
+    SilverJubilee,
+    GoldenJubilee,
+    PlatinumJubilee,
+    Centenarian
+}
+
+impl Age {
+    pub fn get_age(&self) -> &str {
+        match self {
+            Age::SilverJubilee => "25 years",
+            Age::GoldenJubilee => "50 years",
+            Age::PlatinumJubilee => "75 years",
+            Age::Centenarian => "100 years",
+        }
+    }
+}
+
+#[derive(Debug)]
+pub enum EligibleVoters {
+    Juvenile,
+    Teenager,
+    Adult
+}
+
+impl EligibleVoters {
+    pub fn get_eligible_voters(&self) -> &str {
+        match self {
+            EligibleVoters::Juvenile => "17 years and below",
+            EligibleVoters::Teenager => "18 years and above",
+            EligibleVoters::Adult => "35 years and above",
+        }
+    }
+}
\ No newline at end of file
diff --git a/rust_session/student_registry/Cargo.lock b/rust_session/student_registry/Cargo.lock
deleted file mode 100644
index e7f8ee38..00000000
--- a/rust_session/student_registry/Cargo.lock
+++ /dev/null
@@ -1,7 +0,0 @@
-# This file is automatically @generated by Cargo.
-# It is not intended for manual editing.
-version = 4
-
-[[package]]
-name = "student_registry"
-version = "0.1.0"
diff --git a/rust_session/student_registry/src/main.rs b/rust_session/student_registry/src/main.rs
index 7ae18ff7..c4076c08 100644
--- a/rust_session/student_registry/src/main.rs
+++ b/rust_session/student_registry/src/main.rs
@@ -1,11 +1,11 @@
 mod grade;
 mod registry;
 mod student_struct;
-mod utils;
+// mod utils;
 
 use grade::{Grade, Sex};
 use registry::Registry;
-use student_struct::Student;
+// use student_struct::Student;
 
 fn main() {
     // let g = Grade::Second;
@@ -15,29 +15,44 @@ fn main() {
     // let ss = Student::new();
     // println!("stund")
 
-    // let mut reg = Registry::new();
+    let mut reg = Registry::new();
+    
+    reg.add("Victor", 20, Sex::Male, Grade::First, 78.5,);
+    reg.add("Kosi", 22, Sex::Female, Grade::Second, 64.0);
+    reg.add("Yusrah", 21, Sex::Female, Grade::First, 91.0);
 
-    // reg.add("Victor", 20, Grade::First, 78.5);
-    // reg.add("Kosi", 22, Grade::Second, 64.0);
-    // reg.add("Yusrah", 21, Grade::First, 91.0);
+    reg.list_all();
 
-    // reg.list_all();]
 
-    let sex = Sex::Male;
-    println!("sex: {:?}", sex.to_str());
+    let second_id = reg.students[1].id.clone();
 
-    // let s: Student = Student::new(1, String::from("Testimony"), 16, Sex::Female, Grade::Third, 40.5);
-    let s: Student = Student::new(
-        1,
-        "Testimony".to_string(),
-        16,
-        Sex::Female,
-        Grade::Third,
-        40.5,
-    );
-    println!("student here: {:#?}", s);
+    match reg.find_by_id(second_id) {
+        Some(student) => println!("Found student: {} with ID: {}", student.name, student.id),
+        None => println!("Student not found"),
+    }
 
-    println!("student id: {}", s.id);
-    println!("student name: {}", s.name);
-    println!("student age: {}", s.age);
+    reg.update(second_id, "joy", 25, 50.0);
+    println!();
+    reg.list_all();
+
+
+
+
+    // let sex = Sex::Male;
+    // println!("sex: {:?}", sex.to_str());
+
+    // // let s: Student = Student::new(1, String::from("Testimony"), 16, Sex::Female, Grade::Third, 40.5);
+    // let s: Student = Student::new(
+    //     1,
+    //     "Testimony".to_string(),
+    //     16,
+    //     Sex::Female,
+    //     Grade::Third,
+    //     40.5,
+    // );
+    // println!("student here: {:#?}", s);
+
+    // println!("student id: {}", s.id);
+    // println!("student name: {}", s.name);
+    // println!("student age: {}", s.age);
 }
diff --git a/rust_session/student_registry/src/registry.rs b/rust_session/student_registry/src/registry.rs
index 146dc186..83a9ae1f 100644
--- a/rust_session/student_registry/src/registry.rs
+++ b/rust_session/student_registry/src/registry.rs
@@ -7,6 +7,13 @@ pub struct Registry {
 }
 
 impl Registry {
+    pub fn new() -> Registry {
+        Registry {
+            students: Vec::new(),
+            next_id: 0,
+        }
+    }
+
     pub fn add(&mut self, name: &str, age: u8, sex: Sex, grade: Grade, score: f32) {
         let id = self.next_id;
         let student = Student::new(id, name.to_string(), age, sex, grade, score);
@@ -36,4 +43,28 @@ impl Registry {
             );
         }
     }
+
+    pub fn find_by_id(&self, id: u32) -> Option<&Student> {
+        self.students.iter().find(|s| s.id == id)
+    }
+    // - .iter() loops through the vec without taking ownership
+    // - .find() returns the first match wrapped in Option<&Student>
+    // - Option means it can be Some(student) if found, or None if not — Rust forces you to handle both cases, no null panics
+
+    pub fn delete(&mut self, id: u32) {
+        self.students.retain(|s| s.id != id);
+    }
+    // - .retain() keeps only elements where the condition is true
+    // - So s.id != id means "keep everyone whose id is NOT the one we want to remove"
+    // - It mutates the vec in place — no need to find an index
+
+    pub fn update(&mut self, id: u32, name: &str, age: u8, score: f32) {
+        if let Some(student) = self.students.iter_mut().find(|s| s.id == id) {
+            student.name = name.to_string();
+            student.age = age;
+            student.score = score;
+        }
+    }
+    // - .iter_mut() gives mutable references so you can modify fields in place
+    // - if let Some(student) is Rust's clean way to say "if found, do this, otherwise skip"
 }
diff --git a/rust_session/student_registry_v2/Cargo.toml b/rust_session/student_registry_v2/Cargo.toml
new file mode 100644
index 00000000..1bf734cd
--- /dev/null
+++ b/rust_session/student_registry_v2/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "student_registry_v2"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+uuid = { version = "1", features = ["v4"] }
diff --git a/rust_session/student_registry_v2/src/grade.rs b/rust_session/student_registry_v2/src/grade.rs
new file mode 100644
index 00000000..401b0c3a
--- /dev/null
+++ b/rust_session/student_registry_v2/src/grade.rs
@@ -0,0 +1,31 @@
+#[derive(Debug, PartialEq)]
+pub enum Grade {
+    First,
+    Second,
+    Third,
+}
+
+impl Grade {
+    pub fn as_str(&self) -> &str {
+        match self {
+            Grade::First => "Cohort 1",
+            Grade::Second => "Cohort 2",
+            Grade::Third => "Cohort 3",
+        }
+    }
+}
+
+#[derive(Debug)]
+pub enum Sex {
+    Male,
+    Female,
+}
+
+impl Sex {
+    pub fn to_str(&self) -> &str {
+        match self {
+            Sex::Male => "male",
+            Sex::Female => "female",
+        }
+    }
+}
diff --git a/rust_session/student_registry_v2/src/main.rs b/rust_session/student_registry_v2/src/main.rs
new file mode 100644
index 00000000..be68411d
--- /dev/null
+++ b/rust_session/student_registry_v2/src/main.rs
@@ -0,0 +1,49 @@
+mod grade;
+mod registry;
+mod student_struct;
+
+use grade::{Grade, Sex};
+use registry::Registry;
+
+fn section(title: &str) {
+    let width = 60;
+    println!("\n{}", "=".repeat(width));
+    println!("{:^width$}", title, width = width);
+    println!("{}", "=".repeat(width));
+}
+
+fn main() {
+    let mut reg = Registry::new();
+
+    section("REGISTERING STUDENTS");
+    reg.add("Victor", 20, Sex::Male, Grade::First, 78.5);
+    reg.add("Kosi", 22, Sex::Female, Grade::Second, 64.0);
+    reg.add("Yusrah", 21, Sex::Female, Grade::First, 91.0);
+
+    section("ALL STUDENTS");
+    reg.list_all();
+
+    let first_id = reg.students[0].id.clone();
+
+    // section("FIND BY ID");
+    // match reg.find_by_id(&first_id) {
+    //     Some(s) => {
+    //         println!("  Name   : {}", s.name);
+    //         println!("  ID     : {}", s.id);
+    //         println!("  Age    : {}", s.age);
+    //         println!("  Sex    : {}", s.sex.to_str());
+    //         println!("  Grade  : {}", s.grade.as_str());
+    //         println!("  Score  : {:.1}", s.score);
+    //     }
+    //     None => println!("  Not found"),
+    // }
+
+    // section("UPDATE STUDENT");
+    // reg.update(&first_id, "Victor Updated", 21, 85.0);
+    // println!();
+    // reg.list_all();
+
+    section("DELETE STUDENT");
+    reg.delete(&first_id);
+    reg.list_all();
+}
diff --git a/rust_session/student_registry_v2/src/registry.rs b/rust_session/student_registry_v2/src/registry.rs
new file mode 100644
index 00000000..17b33dde
--- /dev/null
+++ b/rust_session/student_registry_v2/src/registry.rs
@@ -0,0 +1,76 @@
+use uuid::Uuid;
+
+use crate::grade::{Grade, Sex};
+use crate::student_struct::Student;
+
+pub struct Registry {
+    pub students: Vec<Student>,
+}
+
+impl Registry {
+    pub fn new() -> Registry {
+        Registry {
+            students: Vec::new(),
+        }
+    }
+
+    pub fn add(&mut self, name: &str, age: u8, sex: Sex, grade: Grade, score: f32) {
+        let id = Uuid::new_v4().to_string();
+        let student = Student::new(id, name.to_string(), age, sex, grade, score);
+        println!("  [+] Registered: {:<16} (ID: {})", student.name, student.id);
+        self.students.push(student);
+    }
+
+    pub fn list_all(&self) {
+        if self.students.is_empty() {
+            println!("  (no students enrolled yet)");
+            return;
+        }
+        println!(
+            "  {:<36}  {:<16}  {:<4}  {:<8}  {:<9}  {}",
+            "ID", "Name", "Age", "Sex", "Grade", "Score"
+        );
+        println!("  {}", "-".repeat(87));
+        for student in &self.students {
+            println!(
+                "  {:<36}  {:<16}  {:<4}  {:<8}  {:<9}  {:.1}",
+                student.id,
+                student.name,
+                student.age,
+                student.sex.to_str(),
+                student.grade.as_str(),
+                student.score,
+            );
+        }
+    }
+
+    // Returns a shared reference to the student if found, or None
+    pub fn find_by_id(&self, id: &str) -> Option<&Student> {
+        self.students.iter().find(|s| s.id == id)
+        // ------ in javascript -------
+        // this.students.find(s => s.id === id)
+    }
+
+    // Updates name, age, and score for the student with the given id
+    pub fn update(&mut self, id: &str, name: &str, age: u8, score: f32) {
+        if let Some(student) = self.students.iter_mut().find(|s| s.id == id) {
+            student.name = name.to_string();
+            student.age = age;
+            student.score = score;
+            println!("  [~] Updated: {} (ID: {})", student.name, id);
+        } else {
+            println!("  [!] Student with ID {} not found", id);
+        }
+    }
+
+    // Removes the student with the given id from the registry
+    pub fn delete(&mut self, id: &str) {
+        let before = self.students.len();
+        self.students.retain(|s| s.id != id);
+        if self.students.len() < before {
+            println!("  [-] Deleted student with ID: {}", id);
+        } else {
+            println!("  [!] Student with ID {} not found", id);
+        }
+    }
+}
diff --git a/rust_session/student_registry_v2/src/student_struct.rs b/rust_session/student_registry_v2/src/student_struct.rs
new file mode 100644
index 00000000..3eaa29e0
--- /dev/null
+++ b/rust_session/student_registry_v2/src/student_struct.rs
@@ -0,0 +1,24 @@
+use crate::grade::{Grade, Sex};
+
+#[derive(Debug)]
+pub struct Student {
+    pub id: String,    // UUID string instead of u32
+    pub name: String,
+    pub age: u8,
+    pub sex: Sex,
+    pub grade: Grade,
+    pub score: f32,
+}
+
+impl Student {
+    pub fn new(id: String, name: String, age: u8, sex: Sex, grade: Grade, score: f32) -> Student {
+        Student {
+            id,
+            name,
+            age,
+            sex,
+            grade,
+            score,
+        }
+    }
+}