Sunday, 6 October 2013

What I look for in a software engineer

When called to assess or interview someone for a software engineering position there are a few things I look for: the core set of knowledge on which we can build upon to support the more specialist or esoteric skills such as security, privacy and the rest. I discussed ideas for what would be required for a grounding in concepts for privacy earlier.

Programming Skill
  • This is obviously the first question - "can you program?" and then in what languages. The usual candidates will always be there, ie: Java, Python, C, C++ etc, but I'd like to see things such as SQL, Prolog, Lisp and maybe things like Haskell, ML, Ada, Eiffel etc. Depending upon the position PHP, Perl, Unix shell script etc.
  • Ideally the candidate should understand and appreciate the differences and respective advantages of the various programming paradigms: structured, object-oriented, functional etc
  • "Programming" in markup languages is not acceptable: HTML IS NOT A PROGRAMMING LANGUAGE.

Design Skill
  • The ability to use design languages such as UML, SDL etc, must always be a prerequisite. Correct use of these come with and comprehension of abstraction and refinement of designs.
  • Abstraction is a very underappreciated and rarely seen skill. The ability to concentrate on what is required without mixing abstraction levels unnecessarily is one of the marks of an engineer.

Discipline and Formality
  • Despite agile being the saviour of everything a true appreciation of what agile actually is, is necessary. The understanding that designs follow a natural flow from concept through design to implementation is invariant - good software can not be hacked.
  • Communication is obviously part of this and clear coding, design and concepts is fundamental.
  • Experience with formal methods is always a clear advantages. Now whether someone actually uses Alloy, B, Z, VDM etc in another matter altogether; the skills and discipline that comes with these is what we're looking for. Some of the best "coders and architects I have come across are formal methods people at heart; indeed I know of on agile guru who attributes his success to applying formal methods within an agile framework (see communication, abstraction and refinement above).
  • This also extends to areas such as testing of code, simulation of design and defensive programming though ideas such as design by contract - all of which contribute to a better quality of development and code.
  • Does the software engineer have a grounding in computer science and/or mathematics? Having this allows the engineer to concentrate on the underlying principles of things without being distracted by arguments over whether something should be represented in XML vs RDF vs JSON, or SQL vs NoSQL etc.
Obviously this just touches the surface of what is required but I hope it gives some idea of what is required. Not all skills are needed, so if someone doesn't have 3 years experience of category theory and programming with monads (the minimum to write "hello world" in Haskell I'm told), but an appreciation and understanding is required.

Ultimately engineering is about solving problem with discipline, rigour and use of the appropriate techniques.

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