Operating Systems — Portfolio Projects

Build these to actually understand OS mechanisms by implementing (simplified versions of) them yourself — the difference between "I read about CPU scheduling" and "I implemented and compared three CPU scheduling algorithms" is exactly what interviewers probe for.

Project 1: CPU Scheduler Simulator (Beginner)

Time: 3-4 days

Simulate FCFS, SJF, and Round Robin CPU scheduling algorithms on a set of synthetic processes (arrival time, burst time), and compute/compare their average waiting time and turnaround time.

Steps

1.Define a Process structure (PID, arrival time, burst time, priority if needed)

2.Implement FCFS (First Come First Serve) scheduling and compute average waiting/turnaround time

3.Implement SJF (Shortest Job First, both preemptive and non-preemptive if you want the extra depth) the same way

4.Implement Round Robin with a configurable time quantum, and observe how waiting time changes as you vary the quantum

5.Compare all three on the same process set — which performs best, and does that match what the theory predicts?

Skills Demonstrated

•Understanding scheduling algorithms at the implementation level, not just definitions

•Comparative analysis of algorithm performance

•Working with queues and process state transitions in code

Repository Name

os-cpu-scheduler-sim

Project 2: A Simple Memory Allocator (Intermediate)

Time: 1 week

Implement a basic memory allocator (your own malloc/free-equivalent) using a simulated memory pool, supporting at least two allocation strategies (First-Fit and Best-Fit), and measure fragmentation under each.

Steps

1.Simulate a fixed-size memory pool (a large byte array works fine)

2.Implement First-Fit allocation: scan for the first free block large enough

3.Implement Best-Fit allocation: scan for the smallest free block that still fits

4.Implement free, including merging adjacent free blocks (coalescing) — this is the part that actually tests whether you understand the mechanism, not just the allocation logic

5.Run a sequence of alloc/free operations under both strategies and measure external fragmentation — which strategy actually fragments less in your test case?

Skills Demonstrated

•Understanding manual memory management at the mechanism level

•Implementing and comparing allocation strategies

•Recognizing and measuring fragmentation, not just avoiding crashes

Project 3: A Toy File System or Deadlock Detector (Advanced)

Time: 1-2 weeks

Choose one: (a) implement a simplified file system supporting basic file/directory operations backed by a simulated disk, or (b) implement deadlock detection using resource-allocation graphs on a set of processes and resources.

Steps (File System path)

1.Design a simple inode-like structure and a simulated disk (a large file or byte array)

2.Implement create, read, write, and delete for files

3.Implement basic directory structure (even a flat one is a reasonable start)

4.Handle the case where the simulated disk is full

Steps (Deadlock Detector path)

1.Model processes, resources, and allocation/request edges as a graph

2.Implement cycle detection to identify deadlock

3.Given a detected deadlock, implement one recovery strategy (e.g., process termination to break the cycle)

4.Test against both deadlock and non-deadlock scenarios to confirm your detector doesn't produce false positives

Skills Demonstrated

•Translating an OS concept into a working implementation

•Graph algorithms applied to a real systems problem (deadlock path)

•Working with simulated persistent storage (file system path)

Repository Name

os-filesystem-sim or os-deadlock-detector

Tips for Great Projects

Implement the mechanism, don't just call a library function. The entire point of an OS project is understanding what's happening underneath — a project that just wraps existing OS calls doesn't demonstrate the same understanding as one that reimplements the logic yourself.

Test edge cases specifically. An empty process queue, a memory pool with zero free space, a resource-allocation graph with no deadlock — these edge cases are exactly where implementation bugs (and interview follow-up questions) live.

Connect results back to theory. If your Round Robin simulation shows a smaller time quantum increasing average waiting time due to context-switch overhead, say so explicitly — connecting empirical results to the underlying theory is what turns a working program into a genuine demonstration of understanding.

For GATE/interview prep specifically: be ready to explain trade-offs — when would you choose Round Robin over SJF, and what does "starvation" actually mean in the context of a scheduling algorithm you implemented yourself?

Project Checklist

•[ ] At least one scheduling algorithm implemented and benchmarked against alternatives

•[ ] At least one project involving manual memory or resource management

•[ ] Edge cases tested explicitly, not just the "happy path"

•[ ] Comfortable explaining results in terms of the underlying OS theory

•[ ] Clear README connecting what you built to the concept it demonstrates

Operating Systems — Projects

Operating Systems — Portfolio Projects

Project 1: CPU Scheduler Simulator (Beginner)

Steps

Skills Demonstrated

Repository Name

Project 2: A Simple Memory Allocator (Intermediate)

Steps

Skills Demonstrated

Project 3: A Toy File System or Deadlock Detector (Advanced)

Steps (File System path)

Steps (Deadlock Detector path)

Skills Demonstrated

Repository Name

Tips for Great Projects

Project Checklist