Zen and the Art of Microservices

For a Software Development professional, one of the earliest truths you learn is that estimating the delivery effort for new system is surprisingly hard. A project manager at IBM told me once, back in the nineties, that the difference between a senior developer and a junior one, can be found in the finely tuned padding he or she adds to their estimates. This is not to say that you won’t be able to quickly develop a sense for the amount of work needed if the subject domain is in your field of experience, but what you learn over time is how much to add for what wasn’t specified explicitly. Frederick Brooks (of The Mythical Man-Month fame) called this the difference between essential complexity and accidental complexity. It leads to the familiar frustration with developers that, even though their estimates were spot-on, the system was nevertheless late, and they get blamed for the discrepancy.

An often heard remark, especially at management level, is that software development needs to get “industrialized”: just like the production of cars and kitchen appliances, writing software needs to becomes standardized to the extent that estimates necessarily improve. This is related to the idea that a higher level of maturity in the software development process will automatically cause the costs to come down. What really messes up these expectations however, is that, in a very fundamental way, producing software is not like producing a car.

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