Advanced Mortgage Calculator




After my first post about a simpler mortgage calculator now I developed a more advanced one, especially designed to compare different mortgages, and calculate which one lets you pay less interest over time.

The app can be found here


Compared to the last tool, which just calculated the total interests and the installment amount, this app offers these other features:

  • charts of the installments over time
  • capability to add different types of events:
    • interest rate change
    • time renegotiation
    • amortization on time
    • amortization on installment amount


Adding events makes this tool extremely versatile and allows for simulating complex scenarios. You can compare a 10 year mortgage with a 20 years one in which you reduce the time amortizations with annual cash deposits, or a combination of different interest rates which may happen in some situations. The charts are updated automatically, and there is a comparison chart to make it easy to compare the two mortgages over time, focusing on the interest amount paid.


Plani3D – Planimetry/map to 3D model

In the last days I’ve been working on this helper software to make it easy to turn a planimetry of a house into a simple 3D model to make it easy to visualize it or any modification you would want to make.





The functionalities are extremely limited and it may be buggy – it was only coded to suit my specific needs.

So far it lets you:

  • Load a custom image (planimetry, map)
  • Define a scale (so the 3d model will have the right measures)
  • Draw 3 types of entity with the mouse
    • Walls
    • Windows
    • Doors
  • Change thickness of walls
  • Generate the 3D model
    • saving the link will let you see it in the future too, the model gets encoded in the url (which could get veeery big)
  • Export the generated model as a GTLF file

Note: no deletion of added walls is possible at this time. Not even editing the generated model. It’s more a rapid prototype tool, doesn’t let you make things precisely.

The project can be tested here.


Heroku free plans shut down

Some of my previous projects (fortunately only 2 of them I think) were hosted on heroku and they are not reachable since heroku shut down their free plan. At some point I will move them to my own server, but it will take some time to do so. In the meanwhile, the urls are gonna return an error page – sorry for that.

Mortgage calculator (fixed rate)

Yesterday I made this fixed rate mortgage calculator because I needed a quick way to calculate different options for mortgages for a friend. I found many calculators online but they were either bloated with ads or not providing enough flexibility.

Here is it: mortgage calculator


As a side note (personal opinion!), I really don’t understand how the typical calculator put emphasis on the monthly payment rather than the total interest money you’re paying in the end. This is very much a disservice for the poorly informed home buyer which looks at a low monthly payments and feels good, when the reality is he’s gonna be paying up to 50% of interest over 30 years of mortgage.. Of course it’s important to be aware of whether you can or cannot afford the mortgage, but in my opinion how much you’re paying for the loaning service is at least equally important. So my tool puts emphasis on how much interest you will pay over the loan lifetime.



Scores is a little app I quickly wrote to scrape musical sheets from the internet and to assemble them in a single PDF ready to be downloaded.

Behind the scenes it uses Python-driven Selenium webdrivers to do the scraping and a combination of carefully crafted hacks to make it talk with the frontend. Security was taken into (some) consideration whereas scalability was not – it only handles one request at a time for now.

Intended for (my) personal use only.



Estimo App

Just a quick update, some weeks ago I rapidly coded a prototype of this idea of an estimation game, in which you have to guess different facts and the app gives an “accuracy” score. Turned out that the problem of measuring accuracy in guessing is an interesting one and could be solved in many ways. My approach was

score = min(guess,realValue)/max(guess,realValue)

To me this metric is interesting because indicates an “order of magnitude” error, that is if our guess is double or half the actual value, the score is the same.

Of course this formula is only good for positive values, and is not that good if we’re trying to guess bounded values, like if I ask to guess the year of birth of someone: you already have some very clear bounds and you will easily get a score of 95% or so.

The (very basic, only mobile) app is here:

I didn’t bother to fix the style for desktop PC – just mobile. Here’s a screenshot:




Party Billboard

After moving to NY, we immediately felt the need to organize some parties to meet some new people. Thus, why not designing something to make the party room a bit more “interactive” during the party?

Here’s where the party billboard comes handy: it’s a meme wall easily customizable by everyone at the party:




The top right QR code takes to the customization page in which it’s possible to customize the meme, by entering a text and choosing between a set of default images or specifying a custom publicly reachable URL to an image or GIF.

It was a cool experiment and it was fun to play with at the last party. Can’t wait for the next one!

A live version (with the limitation of 1000 simultaneous parties) is available here.




Virtual Reality (short post)

Some weeks ago I bought an Oculus Quest 2 and beginning experimenting with WebXR technologies. It’s real fun!

Two little projects I’ve put together are these:

1) Painting stuff in 3d:

You can also read the blog post on my company’s blog (in italian):

2) The cubes game:

Also here we’ve posted to the company’s blog (still in italian):