Knowledge Decay and Accumulation

Ben Northrop wrote about Reflections of an “Old” Programmer which isn’t really about ageism, but rather how a long term programming career seems different than other professional careers. The message is how to stay relevant in a programming career over a long period of time. He sees it as a balance between knowledge decay and knowledge accumulation rate.

It reminds me of Sarah Bray’s concept that you can measure progress by growing faster than you shrink. Ben’s grow is knowledge accumulation rate. The shrink is knowledge decay. He suggests taking a long view on career choices in order to accumulate the right kinds of knowledge to give your career legs.

I’ve seen quite a few colleagues take the bigger pay check at an employer where there’ll be little opportunity to work with new things and learn. In 5 years, they realize that much of their valuable knowledge has evaporated and their pay is way out of whack with their actual worth.

That title of Sr. Developer or Manager means you will spend more time becoming a leader, helping junior devs, reviewing code, attending meetings, etc. So much in fact, that Ben warns:

All of this is eminently reasonable, but it comes, subtly, at the expense of our knowledge accumulation rate.

This is a topic also explored by Cal Newton: Shallow work stops you from getting fired, but deep work is what gets you hired.

Northrop reminds us to invest our limited time learning durable knowledge; concepts like algorithms, security and performance optimization that have a longer half-life than say, an unproven JS framework.

There are some relevant frameworks for how to think about relevant, future knowledge.

  • Uncle Bob’s Type Wars post looks at motivations of past programming languages in order to predict future winners.
  • Thoughtwork’s Technology Radar is a detailed identification of promising tech trends. There are also several opinions on building personal technology radars.
  • As you would expect, there are so many resources about how to choose a JS framework.


  1. Take a long view and consider sacrificing short term salary gains for long term career stability by investing in durable knowledge and skills.
  2. Use a technology radar to focus on and discover durable knowledge.
  3. Grow faster than you shrink. 😉