frontpage.
newsnewestaskshowjobs

Made with ♥ by @iamnishanth

Open Source @Github

fp.

OpenCiv3: Open-source, cross-platform reimagining of Civilization III

https://openciv3.org/
494•klaussilveira•8h ago•135 comments

The Waymo World Model

https://waymo.com/blog/2026/02/the-waymo-world-model-a-new-frontier-for-autonomous-driving-simula...
835•xnx•13h ago•500 comments

How we made geo joins 400× faster with H3 indexes

https://floedb.ai/blog/how-we-made-geo-joins-400-faster-with-h3-indexes
52•matheusalmeida•1d ago•9 comments

A century of hair samples proves leaded gas ban worked

https://arstechnica.com/science/2026/02/a-century-of-hair-samples-proves-leaded-gas-ban-worked/
108•jnord•4d ago•17 comments

Monty: A minimal, secure Python interpreter written in Rust for use by AI

https://github.com/pydantic/monty
162•dmpetrov•8h ago•75 comments

Show HN: Look Ma, No Linux: Shell, App Installer, Vi, Cc on ESP32-S3 / BreezyBox

https://github.com/valdanylchuk/breezydemo
165•isitcontent•8h ago•18 comments

Dark Alley Mathematics

https://blog.szczepan.org/blog/three-points/
59•quibono•4d ago•10 comments

Show HN: I spent 4 years building a UI design tool with only the features I use

https://vecti.com
274•vecti•10h ago•127 comments

Show HN: If you lose your memory, how to regain access to your computer?

https://eljojo.github.io/rememory/
221•eljojo•11h ago•138 comments

Microsoft open-sources LiteBox, a security-focused library OS

https://github.com/microsoft/litebox
337•aktau•14h ago•163 comments

Show HN: ARM64 Android Dev Kit

https://github.com/denuoweb/ARM64-ADK
11•denuoweb•1d ago•0 comments

Sheldon Brown's Bicycle Technical Info

https://www.sheldonbrown.com/
332•ostacke•14h ago•89 comments

PC Floppy Copy Protection: Vault Prolok

https://martypc.blogspot.com/2024/09/pc-floppy-copy-protection-vault-prolok.html
34•kmm•4d ago•2 comments

Hackers (1995) Animated Experience

https://hackers-1995.vercel.app/
420•todsacerdoti•16h ago•221 comments

An Update on Heroku

https://www.heroku.com/blog/an-update-on-heroku/
355•lstoll•14h ago•246 comments

Female Asian Elephant Calf Born at the Smithsonian National Zoo

https://www.si.edu/newsdesk/releases/female-asian-elephant-calf-born-smithsonians-national-zoo-an...
15•gmays•3h ago•2 comments

Delimited Continuations vs. Lwt for Threads

https://mirageos.org/blog/delimcc-vs-lwt
9•romes•4d ago•1 comments

Show HN: R3forth, a ColorForth-inspired language with a tiny VM

https://github.com/phreda4/r3
56•phreda4•7h ago•9 comments

How to effectively write quality code with AI

https://heidenstedt.org/posts/2026/how-to-effectively-write-quality-code-with-ai/
209•i5heu•11h ago•152 comments

I spent 5 years in DevOps – Solutions engineering gave me what I was missing

https://infisical.com/blog/devops-to-solutions-engineering
121•vmatsiiako•13h ago•47 comments

Introducing the Developer Knowledge API and MCP Server

https://developers.googleblog.com/introducing-the-developer-knowledge-api-and-mcp-server/
32•gfortaine•5h ago•6 comments

Learning from context is harder than we thought

https://hy.tencent.com/research/100025?langVersion=en
157•limoce•3d ago•79 comments

Understanding Neural Network, Visually

https://visualrambling.space/neural-network/
257•surprisetalk•3d ago•33 comments

I now assume that all ads on Apple news are scams

https://kirkville.com/i-now-assume-that-all-ads-on-apple-news-are-scams/
1011•cdrnsf•17h ago•421 comments

FORTH? Really!?

https://rescrv.net/w/2026/02/06/associative
51•rescrv•16h ago•17 comments

I'm going to cure my girlfriend's brain tumor

https://andrewjrod.substack.com/p/im-going-to-cure-my-girlfriends-brain
90•ray__•4h ago•41 comments

Evaluating and mitigating the growing risk of LLM-discovered 0-days

https://red.anthropic.com/2026/zero-days/
43•lebovic•1d ago•12 comments

How virtual textures work

https://www.shlom.dev/articles/how-virtual-textures-really-work/
34•betamark•15h ago•29 comments

Show HN: Smooth CLI – Token-efficient browser for AI agents

https://docs.smooth.sh/cli/overview
78•antves•1d ago•59 comments

Show HN: Slack CLI for Agents

https://github.com/stablyai/agent-slack
43•nwparker•1d ago•11 comments
Open in hackernews

Show HN: HCB Mobile – financial app built by 17 y/o, processing $6M/month

https://hackclub.com/fiscal-sponsorship/mobile/
176•mohamad08•2mo ago
Hey everyone! I just built a mobile app using Expo (React Native) for a platform that moves $6M/month. It’s a neobank used by 6,500+ nonprofit organizations across the world.

One of my biggest challenges, while juggling being a full-time student, was getting permission from Apple/Google to use advanced native features such as Tap to Pay (for in-person donations) and Push Provisioning (for adding your card to your digital wallet). It was months of back-and-forth emails, test case recordings, and also compliance checks.

Even after securing Apple/Google’s permission, any minor fix required publishing a new build, which was time-consuming. After dealing with this for a while, I adopted the idea of “over the air updates” using Expo’s EAS update service. This allowed me to remotely trigger updates without needing a new app build.

The 250 hours I spent building this app were an INSANE learning experience, but it was also a whole lot of fun. Give the app a try, and I’d love any feedback you have on it!

btw, back in March, we open-sourced this nonprofit neobank on GitHub. https://news.ycombinator.com/item?id=43519802

Comments

riffic•2mo ago
I really wish something like Hack Club existed while growing up, how empowering! great work.
miroljub•2mo ago
Why does it matter how old is the author?

We should judge software by the quality, not by authors age.

pinkmuffinere•2mo ago
HN isn't a judge of software; it's a place to learn and be curious. So people are often interested in projects that do a novel thing in a normal way, or a normal thing in a novel way. Eg, stories fascinate us because something was built by a very lean team, or a group with no money, or somebody who is an industry outsider, or a parapalegic, etc. Overcoming these limitations is a sort of 'hacking'.
trollbridge•2mo ago
There is a new trend in Silicon Valley of bragging about how young founders are, etc. along with the rather bizarre trend of bragging about dropping out of high school to "found a startup".
rvz•2mo ago
Always has been.

It is a deliberate advertisement to VCs to find "the next Mark Zuckerberg" which the entire point is that there is only one.

For every 1,000+ startups there is exactly only *one* exceptional founder.

recursive•2mo ago
It's quite remarkable that such a loosely quantified pool of startups (1000+) yields precisely one exceptional founder.
Cyao•2mo ago
Totally agree. Even if I'm a teen myself I never post my age unless someone asks explicitly. Saying your age is just trying to find excuses to justify a sub-par software imo (Not saying this project is sub-par)
debo_•2mo ago
Maybe they are rightfully proud that they did this at such a young age?
dang•2mo ago
It's an age-old convention, a way of supporting and encouraging kids, and harmless.
NaOH•2mo ago
>It's an age-old convention....

Bonus points for the wordplay.

skylurk•2mo ago
I am surprised you managed to get those entitlements at all!

Did it help to be a non-profit?

mohamad08•2mo ago
Tbh not at all, the process is tedious but pretty straightforward if you understand the requirements. Apple is did throw at me a huge checklist to finish which did take a while to complete, but after you successfully build the feature and submit test case videos to them its only a matter of time until you receive access to it. For Tap to Pay on iPhone, its very easy to achieve development status if you're just curious about the technology and its applications. Its more the production entitlement in which you must complete the specifications I mentioned before.
sailfast•2mo ago
The OP built the React Native mobile app - not the entire platform / company. Some folks commenting like they built the company. Just a point of clarification.

Great work! Keep building OP!

indigodaddy•2mo ago
The OP title seems a bit misleading notwithstanding this caveat.
kbar13•2mo ago
seems like this is par for course for hustler “founders” nowadays to say half truths to seem groundbreaking to get attention
jeswin•2mo ago
True. But willing to cut anyone under 21 some slack.
Neywiny•2mo ago
I think there's ambiguity. An app built for a platform that does xyz. Does the app do xyz, the platform, or both? If I build an app that takes you straight to idk a Treasury department website, have I built an app for a platform that transacts trillions of dollars?
dang•2mo ago
I thought that at first too, but then I figured it's pretty impressive that the app is processing $6M/month even though the financial platform pre-existed.
mandeepj•2mo ago
It’s the same BS that people have at LinkedIn - leading a $250B initiative or increased revenue by $100B

OpenAI’s executive claiming - made one of the top visited websites :-)

rahimnathwani•2mo ago
This is great!

I'm curious whether you were able to build the app using backend APIs that were already built, or whether building this app created new requirements for those APIs?

mohamad08•2mo ago
Hi! Thank you so much for your kinds work :)

I actually did have to end up creating most of the backend APIs myself too or with the help of fellow engineers at HCB! What I like about HCB Mobile is that I'm not only creating a mobile app but also expanding our API infrastructure to allow for future integration with our platform.

rahimnathwani•2mo ago
Wow that's great experience.

My son is 9yo and loves to make little animations in Scratch. He recently started to learn a bit of Python (just the syntax so far, no projects).

I wonder whether you can share anything about your journey, especially if you have any tips for the stage my son is at.

mohamad08•2mo ago
That's great to hear your son is starting at such a young age! From my personal experience I would recommend focusing more on the concepts (which Python helps with as the syntax is easy to navigate!). Project-based coding is my ideal way of learning as you build things you are truly proud of. I remember when I was young and made my very first Python turtle drawings. Once he turns 13, I highly recommend him join the Hack Club community. Hack Club is our parent organization and its dedicated mission is to help teenagers interested in coding. I believe I wouldn't be where I am today without it. It truly helped me become a better programmer and Hack Club even offers free prizes that help you learn even more such as a Raspberry Pi for those who submit their incredible projects :) Hope that helps! Always down to help if you have anymore questions
LoganDark•2mo ago
> I adopted the idea of “over the air updates” using Expo’s EAS update service.

Be careful with this. If Apple finds out for instance, your app will still be taken down.

rahimnathwani•2mo ago
Many developers do this, and it's explicitly allowed under Apple's Developer Agreement (section 3.3.1).

  Interpreted code may be downloaded to an Application but only so long as such code: (a) does not change the primary purpose of the Application by providing features or functionality that are inconsistent with the intended and advertised purpose of the Application (b) does not bypass signing, sandbox, or other security features of the OS; and (c) for Applications distributed on the App Store, does not create a store or storefront for other Applications.
The app store review guidelines (section 2.5.1) seem more narrow, but I think the above is what's enforced.
LoganDark•2mo ago
Weird, because Apple took down Fortnite for enabling a direct buy-button (bypassing IAP) after review completed. Just because an offending feature wasn't enabled at the time of review absolutely does not mean you're in the clear to turn it on after the review is complete. Whereas before you'd get the opportunity to fix anything like that during the review process, by sidestepping the review process you'd better be confident you don't ever ship anything that wouldn't pass.
DANmode•2mo ago
Not that weird, because they were shiving each other in federal court at the time.
DANmode•2mo ago
I was going to offer a similar, less-absolute warning.
daredoes•2mo ago
Was just looking at this the other day for personal reasons. Great work!
mrb•2mo ago
That's awesome, and impressive you were able to build that. As an angel investor, my first question would be: how do you deal with financial fraud? Like users exploiting your app for money laundering via donations then spending... Any system that lets money get in and out is eventually used as a channel by launderers.
KenSF•2mo ago
HCB is an amazing Rails 8 app. It is the Rails app that is processing $6M/month.

https://github.com/hackclub/hcb

Excellent work on the mobile app though I would wonder, since HCB runs on Hotwire, why it was not written as a Hotwire Native app which would leverage the existing Rails Hotwire app and not require a complete rewrite?

mohamad08•2mo ago
Hotwire Native tbh wouldn't have been a bad choice at all to use tbh. Especially if you wanna maintain 1:1 parity with the website. It combines both being a "web app" and native features we could still use like Tap to Pay and Push Provisioning. The downsides of it is that it isn't a cross platform framework like React so all changes would have to be pushed to both an iOS app repo and an Android app repo. Another downside is that it isn't a "write once run anywhere" type application as you're integrating Hotwire into the native code so you have to be comfortable with both Kotlin and Swift (however if you're writing native modules in React Native same applies).

Both are 2 completely valid and separate paths you could take when building an app and I'd actually be curious what'd HCB Mobile look like if we did use Hotwire Native.

cirrus3•2mo ago
What is this page of transactions for? https://hcb.hackclub.com/hq/transactions

I get that you want to be "open", but is everyone involved in these transactions ok with them being shared? Even if they are, this doesn't seem like a good idea security wise. I see partial account numbers and other IDs/numbers that I assume you'd prefer not be public, regardless of how insensitive they may seem now.

EXPENSIFY, INC. VALIDATION XXXXXX5987 THE HACK FOUNDATION +$0.89

FRONTING $10,000 TO CHRIS WALKER FOR GITHUB GRANTS MADE FROM PERSONAL ACCOUNT -$10,000.00

CHECK TO LACHLAN CAMPBELL +$800.00

Transfer to Emma's Earnings -$1,923.08

galaxy_gas•2mo ago
Please look at this @mohamad08

The numbers and amounts used for account validations and adding it to be able to pull or push money . Should not be shown public..

luke-stanley•2mo ago
They have this page for reporting: https://github.com/hackclub/hcb/blob/main/SECURITY.md
yangikan•2mo ago
Not just for hack club - but transactions for another organization that is using their software is public. https://hcb.hackclub.com/reboot/transactions?page=13

Not sure if all the organizations using their software know this.

garyhtou•2mo ago
Hi @cirrus3,

You've found an optional feature called Transparency Mode!

I admit, this is A LOT of information being made accessible. We at Hack Club (the nonprofit organization behind HCB, and the owner of the transactions above) have chosen to make our finances publicly available on the internet. You can read more about it here: https://blog.hcb.hackclub.com/posts/transparent-finances-opt...

That link (https://hcb.hackclub.com/hq/transactions) shows our donations and spending down to the cent since we believe donors deserve to know what their contributions are funding. As a nonprofit, you can talk about what you’re spending money on, but transparency in every transaction builds trust for supporters. This level of transparency is definitely atypical, and I can see why it may raise concerns.

Other organizations using HCB (such as Reboot) can choose to enable this feature too (it's off by default), and they're briefed on the potential risks and level of exposure to decide whether it's right for their organization/team. HCB supports 6.5k nonprofits, and roughly 64% of organizations have chosen to enable this feature.

> I see partial account numbers and other IDs/numbers that I assume you'd prefer not be public, regardless of how insensitive they may seem now.

> EXPENSIFY, INC. VALIDATION XXXXXX5987 THE HACK FOUNDATION +$0.89

Good catch! Thanks for flagging that verification deposit. I've pushed a fix here: https://github.com/hackclub/hcb/pull/12336

As for the account numbers (e.g. XXXXXX5987) visible in some transactions, these are our own defunct operating accounts, and we're aware they're out there on the internet. We have a new way of managing account numbers via Column.com, so these older transactions are less of a concern for me.

I very much appreciate you bringing these to my attention! We're always looking to improve, so I'd love to hear if you find anything else.

brahbrahbat•2mo ago
This is very helpful to the community. Great work.
throwaway5465•2mo ago
In accounting, finance, M stands for 'mille' aka 'thousand'. So the headline reads $6000/month.

Given how famed HN is for its pedantry I thought you may find this useful as sooner or later someone in your industry might make a judgement on it.

MM is million, BTW.

airstrike•2mo ago
Hardly. I was an M&A banker for a decade in New York and we used `M` for millions across the board. A few people would use `MM` but on every deck I signed off we used `M` for millions, `B` for billions

Some people do use `MM` but it's far from a standard.

DANmode•2mo ago
Mostly Europeans.
esafak•2mo ago
I think being programmers we'd expect K and M. Save the mm for your financial report.
enronmusk•2mo ago
Humanity has moved on from roman numerals 1000+ years ago. Talk about tech debt.

> In accounting

Only in America.

efilife•2mo ago
america is not the entire world

also a simple google search disproves what you are saying. M is correct

ImPostingOnHN•2mo ago
America largely uses K,M,B

Either OP is incorrect, or not American

VoidWhisperer•2mo ago
No offense to the OP (what you did is great - as someone who had to pick up expo/RN on the fly for my newest job, it can be a bit annoying, and that is before all of the compliance nightmares associated with push provisioning) but the title does seem a bit disingenuous - it is phrased to make it sound like the app he built specifically is processing $6M/Month, where it is actually the platform that the app was built for that is
nxor•2mo ago
It doesn't "seem," it "is."
necovek•2mo ago
For something in the financial space, I don't see much (or really, any) tests in the code repository. CI also only has ESlint and prettier running.

How are you ensuring the application will remain maintainable in the future, you are not breaking existing stuff and integration with the actual platform is always up-to-date?

In short, what's the testing strategy for something that claims to deal with $6M a month?

If there is none, you likely want to read up a bit on things like Testing Pyramid, automated test strategies (unit-, integration- and end-to-end testing).

whynotmaybe•2mo ago
Thanks, you just made me realise that I can have OTA update for my app and could deliver more frequently without the play/store hassle!