Not getting involved in more client-facing roles. Use to work for a software services and consultancy company when I had opprtunities to work directly with some clients. Unfortunately switched job to work for a bigger company and since then had little opportunity working directly with customers. I think every engineer should have experience working directly with clients(if the client is non-technical with some business problem to solve then it is even better). It helps a lot. Sitting behind a desk all day long writing code is not good for overall development. Being a cog in a machine kills overall development.