Contributions from users and sponsors help make Advent of Code possible. If your organization is interested in becoming a sponsor for Advent of Code 2025, please email sponsorship at [the Advent of Code domain name].
Advent of Code 2025 is made possible in part due to the following sponsors:
CodeRabbit - Cut Code Review Time and Bugs in Half
We're a research-driven trading firm where curious people work together to solve the puzzle of global markets, with offices in NYC, London, Hong Kong, and Singapore. Check out our new JS Advent of FPGA Challenge!
Happy coding and merry builds from Depot. We keep your pipelines fast, your caches warm, and your logs full of cheer, because the holidays are for shipping joy, not waiting on CI. Ship up to 55x faster with Depot.
We're traders, builders, engineers, and researchers obsessed with improving the models, tools, and systems that power everything we do. From raw silicon through order execution, we tackle problems few ever get to see.
Cloud-native artifact management that handles enterprise security and scale. Artifacts shouldn't slow you down. We run the platform that locks down and distributes your software supply chain, no matter the shape or complexity.
Our engineers build the tech that helps power global markets with speed, precision and data. Every nanosecond matters. Join us at the edge of innovation (Just don't blink. The markets won't).
Build products that make businesses faster and smarter. Work in Python, Elixir, and TypeScript with sharp, curious people who move fast. Main offices in New York and San Francisco. Hybrid.
Become more than a vibe-coder! Master backend development from start to finish on Boot.dev: the most addicting way to learn to code.
Think Santa's workshop, but the elves build low latency code and fine tune algorithms. Curious, collaborative, and full of spirit. If tough problems feel like a holiday treat, you're our kind of developer.
Markets never stand still, and neither do our solutions. Our engineers build and refine systems powering millions of trades a day. Finished today's challenge? Find your next one here.
The fastest growing coding agent because it is open. #1 on OpenRouter. 500k+ Kilo Coders. 6.1T tokens per month. Try it today!
Powered by 60,000 technologists and $18 billion in annual tech investment, JPMorgan Chase is revolutionizing software development to create world-class products.
Squarepoint is a global investment firm that combines rigorous research and cutting-edge technology to develop strategies trading across global markets. Technology is integral to our success, check out our careers page.
We design and operate combinatorial auctions to help financial firms like the ones on here do business with each other more optimally. Come help us use pure math, computer science, and economics to make markets smarter.
Just as you're tackling these daily puzzles with creativity and persistence, our teams are solving complex challenges for federal agencies that protect, serve, and improve lives. We're hiring developers, engineers and more.
Axis - 404: Your application not found! <embedded, cloud, Machine learning, fullstack> Save our Christmas - apply now and join our team!
Infi - Kun jij de bomen door het bos z13n!? Puzzel verder en help boswachter Brian zijn bos in leven te houden in het donker van de Noordpool.
Sony Interactive Entertainment - Pushing the boundaries of Play! /\ () >< []
Ansys - Leveraging the predictive power of physics simulation to empower engineers around the world in achieving breakthrough innovations!
Picnic Technologies - A tech-first approach to online groceries. We are #hiring for Java, React, Python, DevOps, Angular and more!
Source Allies - Learning and leading go hand in hand. Join experts who solve problems w/ an ownership mindset. Make a difference on day one, not one day!
Lightricks - Nerdy and creative? Passionate about AI? We're hiring engineers, developers, and more!
Formlabs - CADing a gift, printing it twice, best-in-class printers make parts come out nice! Ditch the elves, build your next project with Formlabs!
Doppler - No more .env headaches. Doppler automates secrets across CI/CD and every environment. Secure secrets. Ship faster. Try for free today!
NatWest Group - With over 15,000 technologists we're helping colleagues to achieve more for our customers, through brilliant software engineering
Honeycomb - The observability platform that helps teams solve problems they couldn't before, with unified telemetry and fast, powerful querying.
Ahrefs - So we have this crawler, it was working for a while, now we've got 7738405978147 HTMLs and no idea what to do next. We use OCaml BTW.
Fullscript - Unwrap challenges worth solving. Help Fullscript build the future of whole-person care.
CGI - Join our Software Development Revolution. Discover how AI is transforming the way we build software and how we're building what's next.
Kotlin by JetBrains - Join our series of 5 festive livestreams on Dec 1-5 to tackle puzzles in Kotlin with fun guests, warm community, and prizes to win!
BMW TechWorks India - Where coders become creators. Shape software that drives the world. Are you ready?
Shopify - The North Pole's hiring? So are we! Build global commerce infrastructure, ship code that scales, and spread merchant joy year-round.
Air Space Intelligence - Come help us bring ATC and other critical industries into the 21st Century. Built w/Rust & Typescript out of BOS & SEA
Spotify - See how Spotify uses Backstage to manage complex tech challenges at scale every day.
PwC UK - Put your passion for technology to work building trust and delivering sustained outcomes, for business and society.
GitButler - Git, finally designed for humans.
Data Intellect - We turn big data problems into smart data solutions.
Sentry - App monitoring software considered "not bad" by 4m developers.
Open Source Pledge - $4m raised for OSS maintainers so far. Let's do more.
AIS - Think you've got what it takes? Try our 'Can You Hack It?' Challenge.
TNG Technology Consulting - We solve hard IT problems – all year round!
Criteo - Helping Santa prepare for the peak season since 2005
EPILOG - Join the SW development team conquering the world from Slovenia.
Technolution - The best thing from Gouda since cheese!
Grist - The open-source spreadsheet-database that minds its business.
Datasite - {hip, hip} for the Holiday! Work with people who get you.
Splunk, a Cisco Company - Come build a more resilient digital world with us.