Yes Silver Bullet (2019)
blog.ploeh.dk
blog.ploeh.dk
In addition, I agree with the author that the biggest contributions to productivity we have seen were, in this order, the availability of open-source libraries and online forums, automated testing, and garbage collection -- all of which have been adopted at rates we'd expect from adaptive traits in an environment with selective pressure. What is conspicuously missing is linguistic features, also in line with Brooks's observation. And yet the author still claims that linguistic features are the silver bullet. At this point this qualifies as an extraordinary claim that requires extraordinary evidence, but I would settle for ordinary evidence, which is also lacking -- strange, considering that a silver bullet, i.e. something with an extreme bottom-line impact, should be easily observable.
So where do you actually disagree with the author? You don't think the gains from these were substantial enough?
Also the author makes a clear argument for why functional programming is, from a complexity perspective, something entirely different from mere "linguistic features". And a "silver bullet" according to Brooks is something that might take a decade to show full impact.
They are not.
> So where do you actually disagree with the author? You don't think the gains from these were substantial enough?
I think that 1. the collective gains might have been substantial but not 10x, and 2. the very ideas proposed by the author as being a silver bullet are not even among those in the first group.
> Also the author makes a clear argument for why functional programming is, from a complexity perspective, something entirely different from mere "linguistic features". And a "silver bullet" according to Brooks is something that might take a decade to show full impact.
When I was in university, Haskell was all the rage. People were saying how in some years we'll all be programming in it or in a similar language. That was in 1998 or 1999. Functional programming in general has been well known, and taught for many decades. I'm not saying it's particularly bad, and maybe it could even have a small positive effect, but saying it's a 10x silver bullet at this point sounds delusional. If Brooks was wrong and there is a silver bullet, I very much doubt it's something we've known about, and tried again and again, in various forms, for decades.
None of "open-source libraries and online forums, automated testing, and garbage collection" have led to a documented 10X improvement in productivity by themselves, so they are not silver bullets.
It has been popular in some class of languages that directly influence one another, and less popular in others. If you look at the software world in, say, 1995, I think a larger precentage of programming was done in typed languages than today. The question of "to type or not to type" wasn't on anyone's mind because virtually all languages used for serious stuff were typed. In any event, even if there is an MLification in important corners of the industry, it's still nowhere near a silver-bullet level of adoption. There is, I agree, a return to the popularity of typed languages, but it hasn't yet reached the level it was before 2000.
before 2000.
In fairness, the adoption of typed languages in the 1990s was about C/C++, Java, possibly Pascal, Delphi, Ada. None of those languages were built upon ML's innovations (type inference, first-class generics, first class higher-order functions, pattern matching etc). I conjecture that the rise of dynamically typed languages was primarily because the aforementioned typed languages adopted an awkward approach to typing (no inference, subtyping + casting to implement both, ad-hoc polymorphism and generics, or, in the case of C++, generics by compile-time meta-programming which has been awkward in other ways).So 1990s types were a worst-case scenario: not expressive enough for many practical cases (you had to cast a lot anyway), hence the safety you get from typing was not much, syntactically heavyweight, bad error messages. Pointless trivial type annotations like
A a = new A(...);
are truly grating, but ubiquitous in the typed languages popular in the 1990s. No wonder people preferred Python ...Are you sure there was a big rise in dynamic languages at any particular point? I’m not so sure there really was (but I’m interested in documentary evidence if you know of any).
I always figured dynamic languages became more popular as computers got bigger and faster, so efficiency became less important in most scenarios. But that’s not the only trend -- plenty of people programmed in BASIC in the 80s, on tiny 8-bit computers! It was slow as hell, but P-code can be very memory efficient, so even on a tiny slow computer dynamic languages can make sense.
(I count BASIC as dynamic even though it lacks useful abstraction mechanisms because most dialects manage memory for you automatically.)
Edit to add: maybe Forth is a better example (and a much better language!) although I don’t think it was ever as popular as BASIC.
If anything, I see ML as the (spectacularly) successful attempt at typing Lisp for increasing reliability. Remember Milner was at Stanford in the 1960s, surely he will have conversed with McCarty. Milner's early theorem provers were in Lisp. He invented ML to reduce the pain of using Lisp (remember, ML stands for "meta language"), and to make theorem proving less error prone. More precisely to reduce the TBC (= trusted computing base) in theorem provers through types (viz the famous Thm abstraction).
ML was essentially finished in the late 1980s [1]. Every responsible programming language designer could have taken on board ML's lessons sincen, and it's an interesting historical question why this did not happen.
[1] R. Milner, M. Tofte, R. Harper, The Definition of Standard ML. http://www.lfcs.inf.ed.ac.uk/reports/88/ECS-LFCS-88-62/
I started with Haskell, where the main influence besides ML was Miranda. (If I remember correctly, Haskell was only created because Miranda was proprietary; similar to BitKeeper and Git.) I guess Miranda’s main innovation was lazy evaluation. That has certainly been influential but outside Haskell I don’t think it’s ever had widespread adoption in the same way as ML-style typing and type inference.
* Every responsible programming language designer could have taken on board ML's lessons sincen, and it's an interesting historical question why this did not happen.*
Agreed! But maybe it is happening, it’s just that it’s taken 30 years instead of the 5 or 10 one might have expected?
Lazy evaluation was invented multiple times. First in theoretical studies of the lambda calculus by Wadsworth in 1971. Later, Friedman & Wise, and independently Henderson & Morris proposd a lazy Lisp, Turner (who later did Miranda) gave SASL a lazy semantics (SASL was eager initially). All three were from 1976, so it was clearly an idea in-the-air. SASL later evolved in to Miranda. Another of Miranda's innovations was to use combinators for graph reduction to implement the Miranda run-time.
Widget *pw = new Widget(); // heap
Memory is no longer highly constrained
Javascript, Python and Ruby are the big dynamic languages today. But you can go back as far as you like, to when languages like Perl, TCL, Lisp and BASIC were big. There have always been dynamic languages.
Static languages have gotten more robustly type-safe over time (even today’s C is much safer than K&R C). But apart from that shift, it seems to me that the static vs dynamic landscape has been much the same for decades.
Some versions are a little bit richer in that you can have both ints AND doubles (woot, woot!).
Well, who said his prediction turned out to be true? Who actually measured the "impact to productivity" in any quantifiable terms? And who re-did that measurement after "No Silver Bullet, Refired" (which was 25+ years ago)?
The very first piece of software I optimized, I started with “One Mississippi”, moved to a stopwatch app on my PDA, before I ever bothered with instrumentation. Because any idiot can tell 2 seconds from 3, that a boat won’t fit in the garage, or that more than double is way less than ten.
Ironically, if Brooks had said 3x instead of 10x, he might still be right and we’d have invested more in measuring things.
Also, the claim that X has not had a large positive effect requires no evidence. It must be assumed true until proven otherwise; that's just the scientific method. The larger the claimed effect and the longer until it is detected -- especially in a selective environment -- the less likely it is real. However, the claim that something has had a big positive bottom-line effect and yet that effect is not detected in a selective environment that is known to have selected beneficial techniques all the time is false with a very high likelihood to the point of being self-contradictory.
Even if you aren’t on-board with the ones this article mentions, there are a bunch more in this list.. and it could probably do with a refresh soon
I think most Software Engineers probably suffer from some cognitive bias in trying to estimate exactly how much accidental complexity exists that could be eventually removed. We tend to think about incremental improvements to tools and processes rather than thinking at a higher level about improving the overall process of translating business requirements into working software. Even with much better tooling and languages (i.e. #F, Git, AWS, etc) there's still a lot of fat that could be trimmed.
I'm excited to see what the wold of low-code will do to our current assumptions about how much accidental complexity there actually is. Maybe projects like Dark[1] could actually achieve the order-of-magnitude gains that Brooks was convinced wouldn't be possible. Sure, there's no panacea, but maybe we're round the corner from a genuine "Silver Bullet" in the sense that Brooks actually meant.
[1] - https://medium.com/darklang/the-design-of-dark-59f5d38e52d2
I think the modern problem isn't accidental complexity, it's essential complexity that isn't actually necessary for project success.
Same applies to other sorts of possible silver bullets. The Linux kernel has been using git for well over a decade, but even GCC (a free software project which has no managers adding requirements to make themselves look good) only switched to git last week.
In other words, if you have a 10x technical silver bullet against accidental complexity, it won't look like a silver bullet / it'll appear to get stopped at essential complexity until you do the people work too. Without that, you won't be able to point at very many projects that have actually seen the 10x improvement.
That would be a third category of complexity.
Essential complexity Accidental complexity
and the a new one: Complexity-imposed-as-"essential"-by-marketing-customer-etc.
Let's call it Requirements-Complexity
It's not that clear cut.
For me "Essential" is what captures the essence of the problem domain and the requirements in actual use.
On top of that, there are lots of "requirements" that are there due to bribes, idiotic "brainstorming" where everyone felt obliged to chime in, what the CEO's spouse things should certainly be there, recent fads, over-thinking it from some execs, etc.
The distinction between the "essential" is of utmost importance.
First, because these "required but not essential" area is where an engineer can look for tradeoffs (to the benefit of essential areas).
Second, because those items might hamper the essential functionality (like a requirement to build a website in C, because the CEO heard "it's the fastest language", can hurt security, maintainability and other aspects, or the requirement to make a banking webpage with small fancy grey on white fonts because they though the design is "cool" hurts readability).
Third, because engineers should not just operate on a "follow orders" basis. They also have an ethical responsibility towards the final users (society at large for public software, customers, the customer's employees, etc).
And, of course, because not being able to make that distinction, means that the engineer can't tell good from bad, useful for useless, and it's all the same to them. Whether they can convince the customer it's another thing. But engineers should absolutely be able to make the distinction.
>There would be no software if there weren't a set of requirements.
Which is neither here, nor there. There would also be a hell of a lot of better, faster, more reliable software, if bogus requirements would get pointed out, and removed.
I had to step into papi the other day. Most Node libraries for http have been designed by someone who loathes code duplication so much that they don’t care if the user-baby goes out with the code duplication bathwater.
I pray for a day where code is measured not by lines of code or code coverage but by call stack metrics.
But a typical developer is not even coding half of the time! They are discussing with the product owner to clarify requirements, reading specifications, writing specifications, thinking, surfing Jira etc. A lot the work of a developer is to take vague requirements and transform them into unambiguous language. These are effects of the inherent complexity of software development. And then we have stuff like researching and evaluating what framework or library is the best fit for a given task.
Haskell is cool and all, but it will not eliminate 90% of what a developer does in a day. No single programming language, however perfect, will.
https://twitter.com/gravislizard/status/927593460642615296 "almost everything on computers is perceptually slower than it was in 1983" ; https://news.ycombinator.com/item?id=21831931
The whole thread is analogous to a person that grew up on a farm complaining that their Honda civic doesn't deal with rough terrains as well as the tractor on the farm they grew up on did, to which the only response is either duh or no shit sherlock, depending on how charitable you're feeling.
For example, I can commit in my Git clone, can create a new branch, merge a branch, push it to the server, all without GitHub server being available. If GitHub would be down or closed tomorrow, this would not significantly affect my work on the repository.
This wasn't possible using centralized VCSs.
You could do this with a traditional VCS as long as you took frequent backups. Git is an improvement in this regard, but not a revolution.
Furthermore, you are describing a workflow that is inconsistent from many "industry best practice" recommendations. If GitHub went down, a very large number of Git users would not be able to run tests or deploy their code to production - their CI/CD pipelines don't work without GitHub. Their historical record of issues goes away when GitHub goes down, etc.
And I understand that issues and CI/CD will also stop working, but neither of that is part of the VCS itself. I'm not aware of distributed issues (maybe FOSSIL) and CI/CD.
Still it doesn't mean that GitHub makes Git centralized.
Even so, no one prior to Git spent 50% of their time wrestling with the VCS, or solving problems caused by a lack of one.
I think the author of this article is overselling almost every of these advances. Don't software projects still keep failing or being cancelled at an alarming rate, even when doing some or all of these improvements? And there's no compelling evidence that projects using, say, TDD, are significantly more successful, is there?
Then I finally figured out how to simulate user interaction using Elisp[2], and used this to add a test suite to my package. My tests have caught a number of regressions, especially in older versions of Emacs that I no longer use but still want to support. In addition to being faster, development has been much easier and less stressful for me because I know I can experiment and rely on my test suite to catch almost any regression I introduce. And the stress factor is important, since this is an open source package that I maintain for free, and if it was too stressful, I would probably just stop working on it.
Was adding tests to this project a 10x improvement? I don't know, but it sure felt qualitatively like a silver bullet to me.
[1]: https://github.com/DarwinAwardWinner/ido-completing-read-plu...
[2]: https://github.com/DarwinAwardWinner/with-simulated-input
> "While Brooks insists that there is no one silver bullet, he believes that a series of innovations attacking essential complexity could lead to significant improvements."
So I'd say your experience doesn't contradict his point. Automated testing is not an orders of magnitude improvement, and software projects continue to fail or be flawed at an alarming rate, but it definitely helps! (like Brooks also said of high-level languages).
What we have now is the result of refinements and improvements, perhaps it is a series of innovations. You are right - automated testing doesn't refute Brooks.
I have never seen a software project being canceled for technical reasons. Social or political ones otoh...
An example: I attended a conference presentation in which the presenter discussed dissecting the implementation of Identity Server into a dozen sub-services with half a dozen backing data stores with Redis caching layers and an Event Source model for propagating inserts and updates of the underlying data. This would be a prime example of accidental complexity gone wild if you built this just to have a multi-container microservice -- unless your single-signon service as a whole needs to support 100MM+ users, in which case this is essential complexity, not accidental.
Reducing accidental complexity but being mindful of how it could become essential complexity under certain conditions in the future is the mark of a wise architect, IMO.
The title/s are about Silver Bullets, and I strongly do not believe in them.
I've been programming for an embarrassing number of years, and I've seen methodologies come and go. Increasing productivity is about developing a good team culture with a small number of simple tools, not about following the latest Silver Bullet.
In fact, it's very easy to increase the level of accidental complexity by adopting an overly prescriptive or complex tool/methodology (Jira anyone?).
It's also true that overly prescriptive tooling can be such a pain. This also includes automated testing in my opinion (something the author counts as a big advance). It's fantastic for certain classes of software code and terrible for others. I've seen half my team spend multiple days just fixing integration or e2e tests instead of working on features that add value. You can grind to a halt with this stuff just as much as you can grind to a halt because of so many bugs to fix...
You have to find the balance, and I think that's where senior engineers really add value -- they've been round the block a few times and have a better idea where that balance lies.
Most of the accidental complexity I see day to day comes from slow accumulation of errors in craft. Need to validate that an ID is a least plausibly valid, "I'll just match it with a regex here", and in 27 other places in the code, each one added in a different sprint. Little things like referring to data that is passed into an api with the variable name "json" when it is really a data-structure that was parsed from the body of an API request. Is this thing I am manipulating a "tab", a "filter", a "type selector" or a "group"? When methods and variables use a mix of conflicting names for the same concept.
Until we learn, as a profession, that shipping working code is not enough, that our code must clearly, concisely, and consistently communicate the core concepts embodied in the program, accidental complexity will bury us.
Your program needs a way to store and retrieve key:value pairs. It's an inherent complexity your program requires. You solve it by using an industry standard product like Redis. Now your code doesn't contain any key:value logic itself! complexity avoided right? Nope just shifted and doubled or trippled in size to boot. No KV logic but now you have to have db libraries, parameter parsers and sanitizers, sockets between services, etc, etc, so on, and so forth.
It's well trod ground, your IDE will generate 90% of that type of code for you. you throw a library or template or whatever at it and go about your day.
Software isn't just your code. Now your application that needed K:V storage has the entire bug and exploit surface area of your code and Redis. Do this 20, 30, 100 times with other libraries and packages. Each time your code gets a little smaller, a little slicker looking and the actual running software is an unholy monster spread across an entire server cluster. Oh well, your code is clean and tidy.
In the ordinary method, there's a function name, it takes one input, and returns a result; easy-peasy. Yse, what the method does isn't clear, but at least I know the methods name!
Now lets look at the Haskel fuction. tryAccept :: Int -> Reservation -> MaybeT ReservationsProgram Int
I've read enough of these Haskel enthusiast blogs to know that the name of the function is tryAccept (it helps that it's the same as the C# method), and it takes in two parameters, an int and a Reservation and returns a Mayb of a ReservationProgram. And it's somehow an int, so it's like an enum? That's weird, clearly I don't understand Hasket syntax.
And then later, I'm told that it's simple to figure out what a ReservationsProgram is because there's some enum that doesn't include the word "ReservationProgram" in it.
No offence, but this isn't enticing me to Haskel.
I agree that these tools can be productivity enhancers, but if that factor is even 10x that would a huge claim, much less 1000x.
If you have ever watched the hoops somebody jumped through to plug a memory leak in a Java program, you will be forced to agree.
A fundamentally very similar process appears as a functional programmer unravels a program to fix a performance bottleneck. The reason it is similar is that, just as ballooning memory usage indicates a memory leak, a ballooning runtime indicates a time leak.
And, just as GC languages provide inadequate facilities to manage resource use, functional languages provide minimal resources to manage time use.
You could argue that memory and time management are on the accidental side of the ledger, and while the scientist in us would be tempted to agree, the engineer knows that managing limited resources is the essence of engineering, and taking away the tools needed to manage resources makes resource problems balloon out of control, breeding extremes of accidental complexity.
In my observation, a lot of “improvements” in software development are of this kind: they make it quicker and easier to get started, but make troubleshooting a lot more complex specifically because they’ve hidden what’s actually going on in an attempt to simplify things. Not that managed memory is a bad thing! But ideally it would be wielded by people who’d spent a fair amount of time manually managing memory so that they know what to look for.
The author of this post conflates better with a 10x improvement from a few anecdotal experiences that are themselves extremely accidental to the act of creating software. He may have a point about the large volume of accidental improvement areas remaining but I think this is because like the JS ecosystem they are growing faster than we solve them.
I think the reality is likely the author is themselves a 10x improvement over their decade-past self.
Do you have a link to this? I'd like to read it.
Here's [1] a link to his 1995 update, an excerpt from an anniversary edition of 'The Mythical Man Month'
> Software development problems are complex, i.e. made up of many interacting sub-problems. Some of that complexity is accidental. This doesn't imply randomness or sloppiness, but only that the complexity isn't inherent to the problem; that it's only the result of our (human) failure to achieve perfection.
> If you imagine that you could whittle away all the accidental complexity, you'd ultimately reach a point where, in the words of Saint Exupéry, there is nothing more to remove. What's left is the essential complexity.
Okay, that might be a useful way of thinking of things...
But the author then goes on to talk about how he thinks that Fred Brooks underestimated the percentage of accidental complexity in the average project.
However, he then starts to go into things he thinks are "silver bullets", but most of them are tools that, in my opinion, address essential complexity:
* The World Wide Web: in his description, this solves a problem of the complexity of finding how to do things. Can we imagine a solution where finding out how to do things isn't part of the system? No? Under the definition, that's essential complexity.
* Git: in his description this solves the problem of tracking changing source. Can we imagine programming where we don't need to keep track of what source changes happened? I can, maybe, in a distant future where programming is done an entirely different way, but I'd argue that at that point it's not really the same problem. If we're writing code to solve a problem, then tracking changes to that source is essential complexity within that solution.
* Garbage collection: again, maybe there will be a computer that works completely differently (quantum computers?) but under current architecture, the physical machinery of a computer has limited space, so we need to reallocate memory that is no longer being used. That's not accidental complexity, that's essential complexity. There are other solutions to this, but every program solves it in some way, whether it's by reference counting, manual allocation, borrow checking, preallocating everything, or just allocating everything on the stack and copying everything, and each of these has complexity: that complexity is essential.
I think what this all points to is that essential complexity isn't intractable: you can make it someone else's problem. In these cases, we're taking some part of the essential complexity of solving a problem, and letting our ISP and websites solve it, or letting code that we don't maintain solve it. Some of the most powerful tools are ones that solve a form of complexity that is essential to a wide variety of problems.