I am in London for the QCon event, a vendor-neutral development conference which I have been fortunate to attend regularly over the last few years.
These events tend to have an underlying theme, which reflects the current thinking of developers and software architects. Each year I hear cogent and thoughtful explanations of why this or that approach will enable us to code better and please users more. Each year I also hear cogent and thoughtful explanations of why the fix proposed last year or the year before is actually a prime reason why projects fail.
Way back when it was SOA (Service Oriented Architecture) that was sweeping away the mistakes of the past. Next SOA itself was the mistake of the past and we got REST (Representational State Transfer). This year I am hearing how RPC is making a comeback, or at least not going away, for example because it can be more efficient when you want to transfer as little data as possible across the WAN.
Another example is enterprise Java. Enterprise Java Beans and J2EE were the fix, and then the problem, for scalable distributed applications. Rod Johnson came up with Spring, the lightweight alternative. Now I am hearing how Spring has become bloated and complicated and developers are looking for lightweight alternatives.
Test-driven development (TDD) brings fantastic benefits to software development, making it possible to change and improve your code while defending against the introduction of bugs. Yesterday though Dan North observed that TDD also has a cost, in that you write much more code. It is not uncommon for projects to have more test code than code that is active in production. If you did not write that code, you could be doing other productive work in the time made available.
Agile methodologies like Scrum were devised to promote or even create communication and agility in software teams. Now every big enterprise vendor says it does Scrum and runs courses, but the result is a long way from the agile (with a small a) original concept.
This year I have heard a lot about over-optimisation, or creating code for situations that in fact never arise. This is the problem to which the solution is YAGNI (You Ain’t Gonna Need It). Since they apply across all the methodologies, I suggest that YAGNI, and its cousin DRY (Don’t Repeat Yourself), and the even older KISS (Keep It Simple Stupid) are the most enduring software methodologies.
That said, even DRY took a beating yesterday. Greg Young in his evening keynote said that rigorous DRY advocates can end up creating single blocks of code where really the procedure was only nearly the same. If your DRY functions are full of edge cases and special conditions, then maybe DRY has been taken to excess.
In the light of the above, I would therefore like to propose the first draft of my first theorem of software development:
There is no development methodology which will not become a burden when embraced rigidly
The other lesson I have learned from multiple QCons is that effective teams and smart developers count for much, much more than any specific tool or language or approach. There is no substitute.