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Valid point - you eventually want your revenue to be larger than your expenses (unless you plan to get acqui-hired...) Invalid point - you need Excel to figure

Valid point - you eventually want your revenue to be larger than your expenses (unless you plan to get acqui-hired...) Invalid point - you need Excel to figure that out. I think a good hacker is more likely to use some combination of R, Python + Pandas, databases and CSV files to do most of their financial modelling. Then those all-important month-end reports can just be automated away...

kfk 13y ago
I work in finance, I toyed with Python and Pandas and CSV files for a while, it won't do. When you get at it, you soon realize that any kind of decision will have to come from high level numbers, no the billions of rows you hear on HN and, in that area, it makes simply no sense using anything other than Excel.
- maxerickson 13y ago
  Pandas has all sorts of functionality for summarizing data. I can see sticking with the tool you know or preferring a pointy clicky interface, but you are implying the capability to generate those high level numbers is missing, and it isn't.
  - Bsharp 13y ago
    Just because something can summarize data doesn't mean it's the best tool to use when trying to explain something. Executives and VC's with non-technical backgrounds might be intimidated by someone using relatively complex tools for what, to them, could be a basic spreadsheet on a platform they know how to use themselves. Excel's value comes mostly from the fact that everyone knows how to use it at some level, and the formulas are relatively easy to follow, so your audience knows they could probably reproduce and verify your work.
    - xerophtye 13y ago
      Valid Point: High-Ranked execs use it and usually try to translate everything into excel sheets. They would really appreciate seeing excel sheets in presentations. Invalid point: Formulae are easy to follow and audience can easily verify/reproduce your work. My friend, excel rocks when MAKING a spreadsheet, but it can be hellishly annoying to follow. when you got a long chain of formulae cells, it is very annoying to trace the data through it to see where it is coming form. Sure, a properly labelled Sheet takes care of it, but that's not usually the case. That's the main reason i am very excited about that excel-sheet visualization tool posted here the other day.
      - Bsharp 13y ago
        It may be hellishly annoying to follow (and trust me, I've had to clean up many Frankenstein-esque spreadsheets), but it's imo easier than any sort of messy code. Which do you think is harder for Average Joe Exec - following poorly documented and messy code, or following a poorly documented and messy spreadsheet? PS I'm also very excited for that tool. Will make my life so much easier.
      - daemon13 13y ago
        I agree with your valid point, re >> Invalid point: Formulae are easy to follow and audience can easily verify/reproduce your work. Actually this is another valid point of Excel. Unless the financial model was done incorrectly (using VBA, complicated formula chains, unclear logic), it is very easy to verify financial model in Excel, which is a big plus.
        sesqu 13y ago
        Excel has been partly to blame for many bugs in mathematical models, in part because of its datatypes and in part because of its builtins. Some of these bugs are not at all easy to spot, depending on how you go about the building and the verifying.
        PeterisP 13y ago
        What mathematical models? For your company financial assumptions and forecasts you generally need, in essence, the sum(...) function, percentages and multiplication, repeated ad nauseam, and if any of your formulas even have space for 'not easy to spot' bugs then the bug is in thinking of making such formulas in the first place. Your spreadsheets would be big because of quantity of different things included, not because of complexity of those things
- arjie 13y ago
  If it won't take you too long, would you mind sharing a couple of examples?
  - kfk 13y ago
    High level? Think about cash flow forecast. How you do this? You need to model your income statement and balance sheet. Start building up assumptions for: sales (duh), accounts receivables, overdues, your cogs, inventory, possible capex investments, opex, etc. This is very structured data, you can build up hierarchy trees in python, but it will take you too long. Plus, your models will change, people will want to see things from many different changing angles. Unfortunately, every time I start writing about controlling people desert the thread around here, but it is a fascinating topic.
    - malandrew 13y ago
      Go on. I'd like to hear more.
      - kfk 13y ago
        I answer all on this topic, just shoot me an email
  - einhverfr 13y ago
    My obvious example is "what do we have to do to break even?" What a spreadsheet does very well is allow you to quickly run a large set of simulations right next to eachother for comparison. This can be useful in asking questions like, "if we charge $x, and we have $y in fixed expenses, what should our target of support personnel to customers be?"
    - Shamanmuni 13y ago
      You can do that perfectly well with R. Heck, R was designed with that kind of workloads in mind. With RStudio you can even present a table which the non-programmers can directly manipulate to test those conditions. I usually use spreadsheets only as data entry software and then R does the rest.
einhverfr 13y ago
I use a variety of spreadsheets but haven't touched Excel in years. What a spreadsheet gives you, assuming you have enough math skill to operate one reasonably (i.e. at least a year of college algebra), is an ability to create tables of data following certain assumptions that project various scenarios. This is most helpful as a visualization tool. You could probably do something similar with R and some CSV files, but I find spreadsheets are actually really helpful here. PS, I really don't like Excel, just because I have run into so many braindead issues with it. That doesn't say spreadsheets are not a very good tool for certain kinds of problems though.
- yummyfajitas 13y ago
  Of course, if you use python/R, you don't need to manually tweak a few assumptions in a spreadsheet and look at a few outcomes. You can instead just assign them a probability distribution and run a monte carlo simulation.
  - xerophtye 13y ago
    Doesn't that give me an average of the possibilities? I dont think people are usually looking for that... they usually want to specific cases, or graphs. both are very well supported in excel. PS: I think excel probably has some support for monte carlo too. should look into it.
    - yummyfajitas 13y ago
      The output of a monte carlo simulation is a list of N (for N really large) of possible futures. You can average them, you can compute P(business makes a profit), you can do whatever you want with it. If you want graphs you can spit out not just one, but multiple representative ones, credible intervals, etc.
  - daemon13 13y ago
    What for would you need "probability distribution and run a monte carlo simulation"?
  - 13y ago
larrydag 13y ago
I totally agree with your point. Somehow we as technically savvy folks have confused the idea that the tool is more important than the big picture. While tools are great (and I even blog about great tools) it is the knowledge and skill behind the tools that ultimately lead to success. The tool is just an instrument. In other words, a means to an end.
daemon13 13y ago
First and foremost you need to understand finance and the numbers (what is behind them), tool is not relevant for this. However, proper tool does make things more efficient. Based on practical experience Excel is excellent for financial modelling. As for R, Python + Pandas, databases and CSV files - they are mostly useful for supporting and ad-hoc analysis, esp. for sales and marketing data.

kfk 13y ago

I work in finance, I toyed with Python and Pandas and CSV files for a while, it won't do. When you get at it, you soon realize that any kind of decision will have to come from high level numbers, no the billions of rows you hear on HN and, in that area, it makes simply no sense using anything other than Excel.

maxerickson 13y ago
Pandas has all sorts of functionality for summarizing data. I can see sticking with the tool you know or preferring a pointy clicky interface, but you are implying the capability to generate those high level numbers is missing, and it isn't.
- Bsharp 13y ago
  Just because something can summarize data doesn't mean it's the best tool to use when trying to explain something. Executives and VC's with non-technical backgrounds might be intimidated by someone using relatively complex tools for what, to them, could be a basic spreadsheet on a platform they know how to use themselves. Excel's value comes mostly from the fact that everyone knows how to use it at some level, and the formulas are relatively easy to follow, so your audience knows they could probably reproduce and verify your work.
  - xerophtye 13y ago
    Valid Point: High-Ranked execs use it and usually try to translate everything into excel sheets. They would really appreciate seeing excel sheets in presentations. Invalid point: Formulae are easy to follow and audience can easily verify/reproduce your work. My friend, excel rocks when MAKING a spreadsheet, but it can be hellishly annoying to follow. when you got a long chain of formulae cells, it is very annoying to trace the data through it to see where it is coming form. Sure, a properly labelled Sheet takes care of it, but that's not usually the case. That's the main reason i am very excited about that excel-sheet visualization tool posted here the other day.
    - Bsharp 13y ago
      It may be hellishly annoying to follow (and trust me, I've had to clean up many Frankenstein-esque spreadsheets), but it's imo easier than any sort of messy code. Which do you think is harder for Average Joe Exec - following poorly documented and messy code, or following a poorly documented and messy spreadsheet? PS I'm also very excited for that tool. Will make my life so much easier.
    - daemon13 13y ago
      I agree with your valid point, re >> Invalid point: Formulae are easy to follow and audience can easily verify/reproduce your work. Actually this is another valid point of Excel. Unless the financial model was done incorrectly (using VBA, complicated formula chains, unclear logic), it is very easy to verify financial model in Excel, which is a big plus.
      - sesqu 13y ago
        Excel has been partly to blame for many bugs in mathematical models, in part because of its datatypes and in part because of its builtins. Some of these bugs are not at all easy to spot, depending on how you go about the building and the verifying.
        PeterisP 13y ago
        What mathematical models? For your company financial assumptions and forecasts you generally need, in essence, the sum(...) function, percentages and multiplication, repeated ad nauseam, and if any of your formulas even have space for 'not easy to spot' bugs then the bug is in thinking of making such formulas in the first place. Your spreadsheets would be big because of quantity of different things included, not because of complexity of those things
arjie 13y ago
If it won't take you too long, would you mind sharing a couple of examples?
- kfk 13y ago
  High level? Think about cash flow forecast. How you do this? You need to model your income statement and balance sheet. Start building up assumptions for: sales (duh), accounts receivables, overdues, your cogs, inventory, possible capex investments, opex, etc. This is very structured data, you can build up hierarchy trees in python, but it will take you too long. Plus, your models will change, people will want to see things from many different changing angles. Unfortunately, every time I start writing about controlling people desert the thread around here, but it is a fascinating topic.
  - malandrew 13y ago
    Go on. I'd like to hear more.
    - kfk 13y ago
      I answer all on this topic, just shoot me an email
- einhverfr 13y ago
  My obvious example is "what do we have to do to break even?" What a spreadsheet does very well is allow you to quickly run a large set of simulations right next to eachother for comparison. This can be useful in asking questions like, "if we charge $x, and we have $y in fixed expenses, what should our target of support personnel to customers be?"
  - Shamanmuni 13y ago
    You can do that perfectly well with R. Heck, R was designed with that kind of workloads in mind. With RStudio you can even present a table which the non-programmers can directly manipulate to test those conditions. I usually use spreadsheets only as data entry software and then R does the rest.

einhverfr 13y ago

I use a variety of spreadsheets but haven't touched Excel in years. What a spreadsheet gives you, assuming you have enough math skill to operate one reasonably (i.e. at least a year of college algebra), is an ability to create tables of data following certain assumptions that project various scenarios. This is most helpful as a visualization tool. You could probably do something similar with R and some CSV files, but I find spreadsheets are actually really helpful here. PS, I really don't like Excel, just because I have run into so many braindead issues with it. That doesn't say spreadsheets are not a very good tool for certain kinds of problems though.

yummyfajitas 13y ago
Of course, if you use python/R, you don't need to manually tweak a few assumptions in a spreadsheet and look at a few outcomes. You can instead just assign them a probability distribution and run a monte carlo simulation.
- xerophtye 13y ago
  Doesn't that give me an average of the possibilities? I dont think people are usually looking for that... they usually want to specific cases, or graphs. both are very well supported in excel. PS: I think excel probably has some support for monte carlo too. should look into it.
  - yummyfajitas 13y ago
    The output of a monte carlo simulation is a list of N (for N really large) of possible futures. You can average them, you can compute P(business makes a profit), you can do whatever you want with it. If you want graphs you can spit out not just one, but multiple representative ones, credible intervals, etc.
- daemon13 13y ago
  What for would you need "probability distribution and run a monte carlo simulation"?
- 13y ago

larrydag 13y ago

I totally agree with your point. Somehow we as technically savvy folks have confused the idea that the tool is more important than the big picture. While tools are great (and I even blog about great tools) it is the knowledge and skill behind the tools that ultimately lead to success. The tool is just an instrument. In other words, a means to an end.

daemon13 13y ago

First and foremost you need to understand finance and the numbers (what is behind them), tool is not relevant for this. However, proper tool does make things more efficient. Based on practical experience Excel is excellent for financial modelling. As for R, Python + Pandas, databases and CSV files - they are mostly useful for supporting and ad-hoc analysis, esp. for sales and marketing data.