---
title: "Siddharth Lalwani (@siddharthlalwani) | Hashnode"
description: "I like codex and codex likes me back."
url: "https://hashnode.com/@siddharthlalwani"
---

@siddharthlalwani

# Siddharth Lalwani

@siddharthlalwani · Joined September 2026

### [How to Build an Online Judge, Part 3: Running Python in Docker](https://systemsfromscratch.hashnode.dev/running-python-in-docker?utm_source=hashnode&utm_medium=feed)

Learn how to run Python in Docker with bind mounts, read only filesystems, network restrictions, and CPU, memory, and process limits.

13 min read · [systemsfromscratch.hashnode.dev](https://systemsfromscratch.hashnode.dev/running-python-in-docker?utm_source=hashnode&utm_medium=feed)

[Sep 26](https://hashnode.com/posts/running-python-in-docker/6ab7c5a81e80d55a9714effc)

### [How to Build an Online Judge, Part 2: Python Subprocesses Explained](https://systemsfromscratch.hashnode.dev/python-subprocesses-explained?utm_source=hashnode&utm_medium=feed)

Learn how Python subprocess can run child processes, send input, capture output, handle exit codes, and enforce timeouts.

10 min read · [systemsfromscratch.hashnode.dev](https://systemsfromscratch.hashnode.dev/python-subprocesses-explained?utm_source=hashnode&utm_medium=feed)

[Sep 17](https://hashnode.com/posts/python-subprocesses-explained/6aabda495c61af02d3133d31)

### [How to Build an Online Judge, Part 1: Understanding stdin, stdout, stderr, and Exit Codes](https://systemsfromscratch.hashnode.dev/stdin-stdout-stderr-and-exit-codes?utm_source=hashnode&utm_medium=feed)

Understanding how programs receive data, produce results, and report success or failure—the first step toward judging code.

7 min read · [systemsfromscratch.hashnode.dev](https://systemsfromscratch.hashnode.dev/stdin-stdout-stderr-and-exit-codes?utm_source=hashnode&utm_medium=feed)

[Sep 10](https://hashnode.com/posts/stdin-stdout-stderr-and-exit-codes/6aa2df732644e5a77473e445)