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Filters to help decide who might be a software developer
How do you find people who are likely to be good software developers?
I use the filter approach: start with whoever is available, filter out those who are not likely candidates and go with those that are left (if any).
The first filter is a question: which language do you like to program in?
This question is positive, in that it assumes the other person is a developer; asking for the name of a language makes it a difficult to dodge question for those who don’t know any language. The language itself is irrelevant, apart from as a lead in to further discussion.
Learning to program is easy and a fun thing to do, at least if you are the kind of person likely to become a good developer. Cheap computing hardware has been available since the 1980s, the extra ingredients are a desire to write software and some degree of the necessary skills.
The next filter is a discussion about the largest software system they have written.
The theme of the discussion is how they solved the problems encountered during the implementation. Do the problems sound like something a developer of the person’s experience ought to find a problem? How much perseverance was shown in solving the problems, were they flexible in trying alternatives, what was their approach to problem solving?
Building systems is all about solving problems. People who cannot solve problems will fail, those with problem solving abilities might succeed.
What about paper qualifications?
Demand for developers continues to outstrip supply, creating an opportunity for turkeys to fly.
When getting a university degree was intellectually challenging, it was a sign of cognitive firepower. The stated aim of the UK government is for 50% of 18-year olds to study for a degree, which means that courses requiring high cognitive firepower are dumbed down (otherwise the failure rate goes through the roof and a University’s ranking suffers). If the only option is a turkey shoot, a degree in a subject requiring lots mathematical thinking (e.g., physics, chemistry, some psychology subjects, …) is obviously a much better filter than Medieval French, Modern History, etc.
There are people whose path through life has kept them away from computers when they were younger and university when they were a bit older. Software carpentry seems to be doing good things for such people; I don’t have any direct experience of working with those who have gone that route, and so cannot say anything about it.
Will this filter approach work for you? Well, it depends on the characteristics required of a good developer in your line of work.
Perhaps you need a regular Joe, who does the job, nine-to-five, and sticks to the tried and trusted approached; a solid person who keeps systems reliably maintained and customers happy.
The independent, frontier, mentality that thrives in ‘new’ fields is becoming a less tolerated in software development. The frontier shrinks as more and more software becomes good-enough and those with money to pay for change, spend it on something else.
More men than women are incompetent/very competent
Womens’ rights campaigners are always making a big fuss about the huge impact equal rights/sex discrimination laws have had on increasing the career opportunities for very capable women to break the ‘glass ceiling’. The very capable end of the ability scale has always been sparsely populated and any significant impact is more likely to be noticeable in the less capable bands of the scale.
When I started out working in software development, if there was a women working on a team the chances were that she would be towards the very competent end of the scale (male/female ratio back then was what, 10/1?). These days, based on my limited experience, women are less likely to be competent but still a lot less likely, than men, to be completely incompetent.
Based on my experience+talking to others it would appear that women are still underrepresented at the very competent/incompetent ends of the scale in software development. Why might this be (apart from being a sample size issue)? While the average value of male/female intelligence are the same (IQ tests are constructed to make them equal), the variance in IQ between the sexes is very different. The following is taken from Population sex differences in IQ at age 11: the Scottish mental survey 1932
The above plot provides a possible explanation for the prevalence of men at the very competent/incompetent ends of the scale and suggests that women should outnumber men in the middle, competent, band.
In practice there are still far fewer women than men working in software engineering, so a comparison using absolute counts is not possible; good luck running a survey covering software developer competence.
If the above IQ distribution carries over to competencies then it seems to me that those seeking to attract more women into software engineering, and engineering in general, should be targeting the more populous middle competence band and not the high fliers. Companies make a big fuss about wanting high fliers but in practice are often willing to take on people who are likely to be competent if they are the safer choice (that guy who appeared rather unusual during the interview may turn out to be flop rather than a rock star).
O Cobol, Cobol! wherefore art thou Cobol?
Programming language popularity has been in the news again and as always Cobol is nowhere to be seen in the rankings. Even back in the day, when people in the know generally considered Cobol to be the most widely used language it often failed to appear, or appeared very low down, in language rankings. I think Cobol’s unrepresentative rankings occur because users of Cobol are assumed to hang out in the same places as users of other programming languages. The letters bo in the name is the clue, business oriented people are not usually interested in technical stuff and tend not to read the magazines (and these days web sites) that users of the other popular languages read.
Cobol is very business domain specific and does not contain functionality that makes it a reasonable choice for writing applications in other domains (it is possible to write a compiler in Cobol, for instance the Micro Focus compiler is written in Cobol). It has very sophisticated languages constructs for handling data having the most convoluted formats imaginable, essential in the business world which has to process data whose format has evolved over the years into a tangled mess (developers have to deal with spaghetti code, business has to deal with spaghetti data formats). Cobol’s control flow and code structuring facilities are primitive (all variables are global and the perform statement is very similar to the gosub statement found in Basic’s that are line number based) because business data processing tends to be relatively simple and programs to handle them are generally small (the large Cobol programs of legend are invariably made up of lots of small programs run in series with complicated data format dependencies between them).
I started to realise just how different Cobol is when working on my first Cobol code generator (yes it was written in Cobol). If a processor has lots of registers it is usually worthwhile to dedicate one to holding the value zero (of the 32 registers supported by most RISC processors, often only 31 can hold different values, one is dedicated to returning zero when read from and ignores any value written to it), in the case of Cobol it is considered worthwhile to dedicate a register to hold 0x20202020 (four space characters) rather than zero.
Is Cobol still the most widely used language today? No, I don’t think so. Business people love spreadsheets which means developers have switched to writing pre/post data format processing code, previously in Cobol, in Visual Basic (to convert input data into a form accepted by the spreadsheet and then print the results of the spreadsheet calculations in a presentable format); this Visual Basic source can often have a Cobol-like feel to it. This spreadsheet usage also resulted in the comma separated list becoming a widely used format for data representation, eroding Cobol’s unique selling point of sophisticated input/output data format processing.
What does language popularity mean? Does using a language you don’t like count towards it being popular? There are several languages I like and very rarely get to use, does this mean I don’t get to contribute to their popularity?
In these tough financial times the number of job adverts requiring knowledge of a specified language is probably of more interest than number of posts to web sites. One job search site lists 3,032 Cobol jobs and counting job ad hits for the top languages listed in a recent popularity poll puts Cobol at the bottom end of the cluster of highest ranked languages.
On mainframes I think Cobol is likely to still be No. 1; it is probably impossible to replace the dominant language in a niche market.
How widely used is a language?
How widely used is a language? Nobody really knows and since there is nothing anybody can do to control usage (both IBM and the US DOD have tried) the question is probably of only academic interest.
Languages are used in a variety of ways and contexts, and it is possible that while one language currently occupies the greatest number of programmer hours, a different one has the greatest number of lines of code ever written in it, another the greatest number of lines of code currently in existence, and a fourth utilize the most CPU time.
Some languages are very popular for particular kinds of applications or within industries. For example, COBOL is still strong in corporate data centers; Fortran in engineering applications; C in embedded applications and operating systems; C++ and Java for writing desktop applications; Perl, PHP, etc. for web based applications.
There are various methods of measuring language popularity, each subject to a different bias over what is measured, that might be used, including:
- counting the number of job advertisements that mention the language. Money counts, so this may be a solid indicator. However, beware, companies like to paint a rosy picture and sometimes mention languages they don’t use just to attract people to apply for the job.
- measuring the financial value of companies making a living through selling tools for a particular language. As an ex-compiler writer I know that compared to applications software, compilers make very little money (compiler companies invariably go bust or get bought by a hardware vendor looking for leverage). Microfocus is the only (primarily) compiler based company to have grown to a significant size and exist independently for a long period of time
- the number of books sold that teach or describe the language. This will be biased towards the more recently popular languages.
- estimates of the number of existing lines of code written in the language—which will underestimate languages not often found in public searches, e.g., there is very little Cobol source available on the web (is this because the kind of people who write Cobol are not the kind to make it publicly available or are the applications so specialized that web distribution is not considered worthwhile?)
- counts of language references (i.e., to the name of the language) found using a web search engine.
Some of the above material exists in a section of a Wikipedia article I wrote some time ago.
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