Casky – Lightweight C Key-Value Engine with Crash Recovery by pperego

Description

Casky is a lightweight, crash-safe key-value store written in C, designed for fast storage and retrieval of data with a minimal footprint. Built using Test-Driven Development (TDD), Casky ensures reliability while keeping the codebase clean and maintainable. It is inspired by Bitcask and aims to provide a simple, embeddable storage engine that can be integrated into microservices, IoT devices, and other C-based applications.

Objectives:

• Implement a minimal key-value store with append-only file storage.
• Support crash-safe persistence and recovery.
• Expose a simple public API: store(key, value), load(key), delete(key).
• Follow TDD methodology for robust and testable code.
• Provide a foundation for future extensions, such as in-memory caching, compaction, and eventual integration with vector-based databases like PixelDB.

Why This Project is Interesting:

Casky combines low-level C programming with modern database concepts, making it an ideal playground to explore storage engines, crash safety, and performance optimization. It’s small enough to complete during Hackweek, yet it provides a solid base for future experiments and more complex projects.

Goals

• Working prototype with append-only storage and memtable.
• TDD test suite covering core functionality and recovery.
• Demonstration of basic operations: insert, load, delete.
• Optional bonus: LRU caching, file compaction, performance benchmarks.

Future Directions:

After Hackweek, Casky can evolve into a backend engine for projects like PixelDB, supporting vector storage and approximate nearest neighbor search, combining low-level performance with cutting-edge AI retrieval applications.

Resources

The Bitcask paper: https://riak.com/assets/bitcask-intro.pdf The Casky repository: https://github.com/thesp0nge/casky

Advent of Code: The Diaries by amanzini

Description

It was the Night Before Compile Time ...

Hackweek 25 (December 1-5) perfectly coincides with the first five days of Advent of Code 2025. This project will leverage this overlap to participate in the event in real-time.

To add a layer of challenge and exploration (in the true spirit of Hackweek), the puzzles will be solved using a non-mainstream, modern language like D, Crystal, Gleam or Zig.

The primary project intent is not just simply to solve the puzzles, but to exercise result sharing and documentation. I'd create a public-facing repository documenting the process. This involves treating each day's puzzle as a mini-project: solving it, then documenting the solution with detailed write-ups, analysis of the language's performance and ergonomics, and visualizations.

                               |
                             \ ' /
                           -- (*) --
                              >*<
                             >0<@<
                            >>>@<<*
                           >@>*<0<<<
                          >*>>@<<<@<<
                         >@>>0<<<*<<@<
                        >*>>0<<@<<<@<<<
                       >@>>*<<@<>*<<0<*<
         \*/          >0>>*<<@<>0><<*<@<<
     ___\\U//___     >*>>@><0<<*>>@><*<0<<
     |\\ | | \\|    >@>>0<*<0>>@<<0<<<*<@<<
     | \\| | _(UU)_ >((*))_>0><*<0><@<<<0<*<
     |\ \| || / //||.*.*.*.|>>@<<*<<@>><0<<<
     |\\_|_|&&_// ||*.*.*.*|_\\db//_
     """"|'.'.'.|~~|.*.*.*|     ____|_
         |'.'.'.|   ^^^^^^|____|>>>>>>|
         ~~~~~~~~         '""""`------'
------------------------------------------------
This ASCII pic can be found at
https://asciiart.website/art/1831

Goals

Code, Docs, and Memes: An AoC Story

• Have fun!

• Involve more people, play together

• Solve Days 1-5: Successfully solve both parts of the Advent of Code 2025 puzzles for Days 1-5 using the chosen non-mainstream language.

• Daily Documentation & Language Review: Publish a detailed write-up for each day. This documentation will include the solution analysis, the chosen algorithm, and specific commentary on the language's ergonomics, performance, and standard library for the given task.