The first skill any developer needs to have is an ability to work with programming languages and the main tools that are used with them. These could include build tools, IDEs, web frameworks, messaging APIs.

Although Martin Fowler talks about how he prefers design skills over language skills, I think it is important that you do have a good level of knowledge of at least one language.

These skills can best be acquired through practice, learning APIs, playing around with different frameworks etc. There are also infinite books available which go through the features of different languages which I won’t list here.

In a Java development environment you might need skills in some of the following, for example:

Clearly the more languages and tools you are familiar with the more useful you become on any team you’re on. Knowledge of different types of languages (e.g. static/dynamic/functional) can help bring different points of view in understanding how to solve problems.

This concerns the design skills which Martin talks about. Martin covers it in much more detail, but one area this would cover is having a good understanding of object orientation which is vital for writing maintainable code with imperative languages.

An understanding of ways to approach different problems you might encounter in enterprise development by knowing different patterns and when to apply them is also useful.

The following books would make good reading in this area:

Specific knowledge about the domain (e.g. Investment Banking) is vital for writing a system which is closely linked to the problems it is trying to solve.

Although a lot of this knowledge is acquired by the Business Analyst on the project if Developers can gain it too then conversations with users will be much easier to deal with as amongst other things the terminology they use will make sense.

Beyond this it is useful to understand the goals the business people have, the processes they use to achieve those goals. An understanding of the history of their business so you can see where their industry is going and why is useful for context.

Some domain knowledge can be gained by reading books - this is especially true once you start reading the books that practitioners are reading - but a lot of the knowledge can only be learned by speaking to or watching people who do that job for a living. For example I found out that Options, Futures and Other Derivatives is a very popular book in the investment banking world from my time working in that environment.

Eric Evans' Domain Driven Design details a way of writing code specific to the domain that you’re working in. Specific domain related books are probably best located with an Amazon search.

With regards to learning domains, the approaches one can take vary from focusing very heavily on one domain and learning it inside out to getting an understanding of a broad set of different domains.

One of the most important skills in software development is the ability to work effectively with other people - fellow developers, Quality/Business Analysts, clients, users, the list is endless. If you can do this effectively then you go a long way to ensuring your success.

All the skills of Emotional Intelligence as Daniel Goleman has termed it.

Some useful reading around this area:

The ability to solve problems that don’t have an obvious solution is key in software. Coding wise it could be debugging a class-path issue when deploying your application to JBoss or finding a tricky bug that a test reveals.

I found Debugging: The Nine Indispensable Rules for Finding Even the Most Elusive Software and Hardware Problems to be very useful reading around this area as it helps to keep you honest when solving coding problems and not over thinking the problem.

The best problem solvers logically go through the problem logically using small steps, investigating potential causes until they solve the problem.

The art of managing your time effectively, prioritising your work correctly and keeping focus on what’s important. GTD is a famous book in this area although I think it comes down to experience and understanding the way to best exploit the way that you work.

This links to people skills but includes written communication, how you transmit ideas and your ability to persuade people.

These skills come in very useful when taking part in exercises such as pair programming for example.

I have read a lot of information around Neuro Linguistic Programming (NLP) in this area - Introducing NLP is a useful book to start with on this subject. NLP amongst other things is a gathering of techniques which effective communicators have been seen to use. NLP Weekly is a useful online resource.

Acknowledging when the facts don’t match your theory and keeping room for possibility. In other words approaching things with an open mind, keen to learn other approaches to solving problems.

The ability to learn how to learn - the skill of skill acquisition - as well as knowing which skills to learn next and which to abandon.

Andy Hunt’s Pragmatic Thinking and Learning strikes me as a book which covers most of these things. It has only recently come out but I will review it when I get my copy.

There are bound to be things I haven’t considered for this list. I would like to hear other ideas. My underlying desire is to hear the skills that people are developing to make themselves a better software developer.

Construx have the idea of a Professional Development Ladder but I think you need to be a member to see a proper version of it.