In my not too long experience as a software developer, I have encountered with people (usually my bosses) using software which is very much not suitable for the scale of the project I was working on. This, combined with the fact that they are usually expert in areas other than IT, lead to wasted working hours and frustration numerous times. Despite me pointing this out, nothing has changed, and I was still expected to use that technology.

(Concrete example: linguistics-based project involving loads of data. Boss with linguistics background uses Microsoft Excel. It didn't always work as expected & I found this out, and I suspect there were cases where it didn't work as expected without me discovering it. I was hired as a Python developer. Now I read that some other people are also not able to use that product well, while the stakes are high (here, here, here) - now, partly owing to their mishap, COVID cases are also skyrocketing. Also happened in a genetic study & in one of Scotland's elections.)

I am likely to work for a company where I can dictate the conditions at some point in the future.
Is it professional, or common, to write a contract which includes that I will under no circumstances will use a certain technology (in my own case, Excel), because in my past experience, it is a source of frustration and dangerous unexpected behaviours?
If yes, should I include a reason, or just state the fact?

To address the issue that some pointed out - that I am not in a position to dictate the conditions: That is probably true in most cases, however, I have reasons to think that it is not the case now. I worked on projects which were very much in need of manpower, and I got to dictate many other aspects of the conditions, such as number of hours worked in a week & my salary. I got away with not having fixed working hours, as long as I have done the job, it was fine. Not as a result of my own excellence or anything like that, but due to my fortunate schooling background in my past, I had the opportunity to study in very prestigious universities. I do not think that this makes me a significantly better developer, but it does seem to boost my CV among the eyes of the employers. And if I did not like the company, I could always walked away, because I had other options. These factors combined, I have had big leverage in the conditions.

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    Comments are not for extended discussion; this conversation has been moved to chat.
    – DarkCygnus
    Commented Oct 6, 2020 at 1:22
  • This is just one of those things that cuts both ways. It's entirely up to you which direction you want it to cut! Option 1: "When I was working on a linguistics-based project we had so many issues with Excel, I replaced their outdated methods with a Python solution and saved $X per month" Option 2: "Excel is evil and I refuse to touch it with a ten-foot pole!" Who do you think I'm going to want to hire? I hope you see what I'm getting at here. The point is not that it's bad to have strong opinions. It's up to you whether you want to use it to your advantage, or let it work against you.
    – Steven Lu
    Commented May 5, 2021 at 4:03

13 Answers 13


TLDR: Yes, it is unprofessional.

If I were to read such a thing in a contract, I'd simply think I was dealing with someone who would be too difficult to bother with, and move on to the next person.

Putting such a thing in a contract sends a message that you are unwilling or unable to handle the technology you are excluding to the point of being a hindrance instead of a help. It makes you look petty and unwilling to bend, adapt, or help. It indicates a rigidity of thinking that is not conducive to solutions, especially if stop-gap measures are required. People in IT have a bad reputation as being rigid and difficult. Such a clause would not do anything to dispel that stereotype.

You learned from your experience, but you learned the wrong lesson.

Instead of writing it into your contract, speak to your misgivings and advise on them after your hire and document all your concerns.

Otherwise, seek employment elsewhere, but do not try to dictate the terms of what you will use or you simply will not be hired.

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    Comments are not for extended discussion; this conversation has been moved to chat.
    – Neo
    Commented Oct 6, 2020 at 12:22

You're asking the wrong question. The question is: Will you avoid wasting your times with jobs requiring Excel when you have no intention of ever using it (most likely "yes"), and: Will it negatively affect your ability to get jobs that do not require the use of Excel?

Where I work, no developer job will require you to use Excel for software development purposes. But if we found this as a requirement in your CV, we would be very surprised and see it as a rather big red flag. I personally would expect any developer to be able to use a spreadsheet to save some small table, or do a few calculations that are to hard to do in your head and too big to do with a calculator.

So I think this will prevent you from getting some good jobs.

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    It is also quite common to be asked to write something that exports your data to csv and xlsx. With the definition of "correct" being that it can be opened in Excel, so one would need Excel to confirm that the software works as intended.
    – Jan
    Commented Oct 5, 2020 at 23:44
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    Exactly this. At my company the Sales team occasionally needs a new metrics report. I can add it as a query in our internal data / reporting base. But I still need to download it in Excel / csv and verify that all the formatting and column names look correct. Commented Oct 6, 2020 at 0:08
  • I've done a great deal of work with Excel where licenses were an issue. I've also worked a few places where it was used as a front end to quickly format and calculate data. Commented Oct 6, 2020 at 19:31
  • For personal experience, marketing, boss or non dev ask me to give results in excel sheet so that they can do the graph the way they want to without bothering me. In the end you're paid to do what your boss wants to. If he isn't a cto or tech lead, that's also your job to tell him he is wrong about tech choice.
    – None
    Commented Oct 8, 2020 at 9:22

As an employee, you will never be able to write into a contract which software you won't use.

The best you can do, as eg a Python Developer, is to make sure that your contract specifies your work duties as developing Python Software. And quiz the company about their tech stack in general and their use of Excel specifically. Not "I refuse to use it" but "I want to understand what you use, where, how, etc".

Your work duties won't stop you from ever working with Excel, but will mean that it can't be more than a minority of your time without giving you cause to end the contract.


Not the best approach

As a professional you should be able to work with every tool in your job description arsenal and be ready to learn / adapt a new ways of doing things, technology is a fluid field and changes constantly

Every goal has a best fitting tool and plethora of other tools that have different degrees of "ish" fit

IMHO, when you state that specific tool is on your black-list, you limit your set of accessible tools and when someone see that thing in a contract, he will automatically think what other limits and restrictions you may have that are not revealed yet.

may decide not to bother

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    Especially when the tool you are black listing is the backbone of pretty well every business from small to large.
    – Peter M
    Commented Oct 5, 2020 at 15:47
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    @PeterM while it is true, my specific job has involved passing different kind of data from Excel into Python. The old xls version of Excel is abhorrent at representing simple data types reliably. The worst thing is that these problems appear randomly in positions which didn't exhibit issues earlier, or were already patched for (other) Excel quirks. I agree with the answer, but older Excel format (which is still around a lot) can silently lead to bad data.
    – Gnudiff
    Commented Oct 5, 2020 at 22:50
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    @Gnudiff: See also scientists changing the names of human genes because Excel thought they were dates...
    – Kevin
    Commented Oct 6, 2020 at 1:12
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    @PeterM and excel can be a good tool for non programmers to show the logic they have in mind, or at least what inputs and outputs look like. Commented Oct 6, 2020 at 2:27
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    @Gnudiff If you think that "legacy software has bugs/bad design decisions that require workarounds" is something unique to Excel, you'll be in for a rude awakening. Is the excel behavior incredibly stupid? Oh yes. But then literally any long-living application/technology will collect a whole bag of those from operating systems to databases to business applications to programming languages. If they don't they just weren't successful enough.
    – Voo
    Commented Oct 6, 2020 at 8:39

There are already good answers, but there's another angle to consider: a real-world blacklist is never complete. What happens if it turns out the employer is using another spreadsheet, like LibreOffice or Google Docs? What happens if they use an even worse technology stack, like a horrible mash-up of [least-favourite language], [proprietary GUI regex processor] and [custom-patched shell tool from the 90s]? Your contract doesn't mention any of these, and you can't possibly "outlaw" all the technologies you consider unfit for purpose. In other words, you can't possibly formalize "use the right tool for the job" in a contract.


Is it professional, or common, to write a contract which includes that I will under no circumstances will use a certain technology (in my own case, Excel), because in my past experience, it is a source of frustration and dangerous unexpected behaviours ?

Well, if the company insists on using the technology that you will under no circumstances use (all companies use Excel, in your own case), then you will never get to the phase of writing a contract. Additionally, companies do not like ultimatums at all.

Bottom line: do not worry about the professionalism of something that will never happen.

Note: you will not add anything to any contract. The companies reserve the monopoly of doing that. You just sign it, if you get so far in the recruiting process.

Note 2 (tnx for the comments): you may be able to influence the contract with reasonable demands. If the company agrees to the terms, they will add them to the contract.

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    As simple as it gets +1. Though I would have to disagree with the last line, you certainly can negotiate the contract and have the terms there changed. But the term OP wants is not going to happen.
    – Aida Paul
    Commented Oct 5, 2020 at 13:43
  • @TymoteuszPaul: he will make that statement early enough in the process, and there will be no contract negotiation - my best guess. I almost hear him telling how "inappropriate" were his previous bosses - just to explain why he will never use Excel. BA-DUM-TSS... do not call us, we call you...
    – virolino
    Commented Oct 5, 2020 at 13:50
  • While I agree that the general statement OP made likely will stop the process when he demands it (unless he finds someone who hates Excel just as much, which would be a win-win^^ but is unlikely), the last line sounds very general and in that general reading I have to agree with @TymoteuszPaul that you can influence your contract. Perhaps it's the company who technically will adapt the written piece of paper, but they may well do so based on your feedback/demands - as long as you can find common ground and get as far as to write up a contract. So that just sounds too one sided. Commented Oct 5, 2020 at 16:21
  • I.e. the underlying issues is not that no company would ever bulge to adapt a contract, it's that the specific demand OP made is highly unlikely to ever be accepted by a company. It's not that the contract is 100% dominated by them, but that they are a partner that needs to agree with you and they very likely will never agree with such a statement. (In general terms, it's just too much weird detail in a general work contract). Commented Oct 5, 2020 at 16:25
  • @virolino, I do not plan to complain about my previous bosses (or anyone, on that matter), in a job interview.
    – anon
    Commented Oct 5, 2020 at 17:20

Your goal must be to use the best (available) alternative.

You pretty much said that on

I have encountered with people (usually my bosses) using software which is very much not suitable for the scale of the project I was working on.

However, you reach a wrong conclusion

I will under no circumstances will use Excel

You should (try to) use the best technology. Even if that's Excel. However, if Excel is a bad solution for the problem at hand then, obviously it should not be used.

There are cases where a spreadsheet is the best solution:

  • It involves numerical calculations
  • You already have the required software licenses
  • Your users have experience using the software
  • There is historical using that format
  • etc.

Mind you, the definition of best is generally dynamic. When you have certain team the best solution may be PHP while with another team for that very same project it may be Java. Just based on the people and their experience with those technologies. It's also very different to design a new project from the ground up, with a 20/20 vision of its scope, than creating a quick proof of concept or developing upon something with an existing history that must be taken into account (e.g. your code is intended to seamlessly replace a module whose input or output are xlsx files).

As for the question of stating it on a contract, yes, it's a bad idea. You might even be the one that happens to wish you could use that technology, but your past self tied your hands. What you could do is to positively state in the contract what you would do, so that you could argue “Sorry, I am a Brainfuck programmer, I have no idea (and I am not required to) how to use Excel/Windows/BSD/a firewall.”

However, be aware that might be replied with "Well, then you are fired, as you are not of any use to me.". You could face the same with a contract stating you would not use Excel, though, so it's not a big difference. Also, contracts generally contain a broad clause such as "and whatever you are asked to do".

I got to dictate many other aspects of the conditions, such as number of hours worked in a week & my salary.

The technology is generally quite different than the salary. Salary and number of hours is usually handled by HR, whereas the technology used would be decided by the project architect. You would want to have a say on that decision (or simply not be on a project with dumb ones). If you work on a per-project basis (such as doing freelance work), then you would probably want to have the technologies to be used fixed before signing the contract (or ensure you get to choose those you may want). You won't want to sign a contract for doing X, just to discover later it actually needs to be done on a hellish language out of TDWTF, much worse than any Excel abuse.


Most companies use Excel, only a few use it innapropriatly so it is a bad idea to say you won't use Excel. I have had to use Excel in an inappropriate way myself, at least I got to learn how to programmatically construct an Excel spreadsheet, which on its own was a useful experience, even if it was the wrong use of Excel. It will be a rare situation where you use technology inappropriately over and over, but it isn't unheard of, some accountants think Excel should be used for everything

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    "Most companies use Excel, only a few use it innapropriatly" Take the UK government, which just had to admit that they missed about 16,000 COVID infection cases because of inappropriate use of Excel.
    – gnasher729
    Commented Oct 5, 2020 at 22:09
  • @gnasher729 don't assume Excel was used, they are just as likely to have used the Excell file format due to common surport as a export format from many systems.
    – Ian
    Commented Oct 5, 2020 at 22:25
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    @Mikesplace that was clearly being stated as an example of the "some", for one thing. And it's extremely unclear why you're suddenly bringing government vs. private enterprise into things. But congratulations on turning an entirely innocuous comment into an opportunity to yell about communism for some reason.
    – Chris H
    Commented Oct 6, 2020 at 8:47
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    @ChrisH You don't understand! Communists are destroying the world as we speak! /s (it's amazing what people will be scared of when their propaganda source tells them to be) Commented Oct 6, 2020 at 10:04

I don't know about "professional" or "common" but if you are going to include something like that on your resume, it would probably be wise to include reasoning. Because a simple "I absolutely will not work with MS Excel" is likely to be met by many employers with the reasoning:

"He won't use Excel? But we do use Excel. Next."

Keep in mind that employers most often have many more applicants than they have positions to fill, so any reason they can find to whittle down the pile will be jumped upon with aplomb.

A better course of action might be to say nothing about Excel on your resume, or in your contract, assuming you get to that stage. Instead, prepare a presentation about why Excel is the wrong tool for what you're doing and keep that in your back pocket for if and when they ask you to use it. In this presentation you should include your reasons for not liking Excel, as well as few alternative programs that you feel will do the job better and your reasons for preferring those programs. If you can also include some kind of cost/benefit analysis for the bean counters, so much the better.

Get hired first, prove your worth as an employee, and then teach them why this is a bad choice once they trust your ability to do the job. If a given employer insists that you use Excel, then it may be time to move on to greener pastures, until such time as you are, indeed, in a position to dictate what software gets used without your presentation.

  • Ii think you mis-read the question: OP wants the info in the contract, not in the CV.
    – virolino
    Commented Oct 5, 2020 at 13:42
  • @virolino Yeah I know, but trying to get a clause like that added to the contract is risky in the best cases, even less so if he doesn't at least mention it in the resume first. I mean, here they are thinking they've found a great employee. They send him an offer and he comes back with "let's add a line about never asking me to use Excel" completely out of the blue? I don't see that going over any better.
    – Steve-O
    Commented Oct 5, 2020 at 13:45
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    I understood what you meant, but the answer and the comment do not offer the same info. If you merge the comment to the answer, it gets better. IMHO (not my downvote)
    – virolino
    Commented Oct 5, 2020 at 13:46

If you really feel strongly enough that you would rather pass up a job than work with Excel (or any other specific technology), the way to approach it in a contract is to require "working with your own choice of suitable technologies", rather than specifically banning this one. Stating you are against one of the major known tools will get you rejected quickly, being able to argue that you want to always be able to choose the right technology for the job may be more acceptable.

Note that you will almost certainly still need to be able to output your reports to colleagues and management as Excel Spreadsheets, as well as import data from existing Excel Spreadsheets you are sent. And still have Excel installed somewhere so you can read all of those annoying attachments in your email before you want to convert them.

Even if you are as sought-after as you think, I suspect that is about as far from Excel as you are likely to get, unless you join a really small company which either doesn't use it already, or where you can embark on an Evangelical quest to convince them to change to your preferred technology.


Sure. Job interviews are a two-way process.

Remember, a job interview isn’t just a way for a company to find a good employee: they’re also a way for prospective employees to evaluate the company.

Some of the answers given here are to the effect of “have fun not being employed”, but that’s entirely the point of making a request like this: anyone who would refuse to hire you over this is someone you wouldn’t want to be working for anyway.

Excel has a very limited use in a serious data science environment (making ugly graphs quickly, to get a rough idea of the tendencies of your data), but any serious analysis or visualisation of the data should be done using more appropriate software.

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    Do you have personal experience with this? I don't find it unlikely that somebody who has no intention with ever working with Excel would not hire someone who makes the request of never working with Excel.
    – guest
    Commented Oct 5, 2020 at 15:32
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    Sure, if you're mining large datasets, Excel is the wrong tool to use. However Excel has very real uses in every other area of science and engineering. Word and Excel are simply tools like a hammer or a screwdrivers, and I'd expect my colleagues to be competent with the tools of their trade. A mechanic who refused to use a screwdriver on principle would clearly be acting ridiculously; and an engineer or scientist refusing to use a spreadsheet on principle is the same. The point isn't just that the OP would not want to work for them; it's that the OP will not find anyone they could work for.
    – Graham
    Commented Oct 5, 2020 at 23:23
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    @Graham The only legitimate use for Excel in science and engineering is the one I listed in this post: making ugly looking graphs quickly, to get a rough idea of what your data looks like. For everything else, you should be using a proper programming language. The person who’s acting unprofessional is the person asking them to use Excel, IMO.
    – nick012000
    Commented Oct 6, 2020 at 0:04
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    @nick012000 The question is about professionalism and contracts, perhaps your answer would be better received if you focused on those issues. Commented Oct 6, 2020 at 1:08
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    @nick012000 I never mentioned programming. Excel has many uses around those "ugly looking graphs" which are important for a business, and no company I've ever seen would consider a candidate who refuses to use it. Similarly LaTeX may give you pretty documents, but no company would consider a candidate who refuses to use Word.
    – Graham
    Commented Oct 6, 2020 at 8:28

Rather than ban out $PHBWare, ask to have autonomy to select your own stack.

Lots of our devs have complete, formal control over their own choice of editor and IDE and we encourage that.

This will give you your desired outcome (the ability to control your own selection of optimal tools with minimal interference from unqualified and untalented management), while not coming off as strange ("how come he won’t use Excel, EVERYONE uses Excel!").


If you can land the contract, you can write it any way you like!

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    This reads more like a comment rather than an answer... Please enhance it
    – DarkCygnus
    Commented Oct 5, 2020 at 19:50

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