Mind that the parent poster didn't claim that experience was not valuable in web applications; just that there were diminished returns.
Embedded systems programming is far more architecture and device specific than web applications are, thankfully. Embedded systems programming requires a much large body of knowledge: chipsets and their features, device-specific options, the behavior of the RTOS (if there is one), esoteric configurations in the cross-compiler or build tool, ability to interactively debug (read the instruction set, use the interface (JTAG, etc), cope with interrupts), ability to thrive with extreme resource limits, and write comprehensive tests with a nearly-exhaustive test plan; since a final release can't be rolled back once customers have purchased it.
This isn't because of some inherent superiority or prestige of embedded systems programming (salaries are lower across the board compared to backend applications programmers), it's just plain more complicated.
A 20-year senior backend programmer should really have progressed to an architect or principal engineer role at that point in her career. An embedded systems developer with 20 years of experience is more typical because of its inherent complexity.
Embedded systems programming is far more architecture and device specific than web applications are, thankfully. Embedded systems programming requires a much large body of knowledge: chipsets and their features, device-specific options, the behavior of the RTOS (if there is one), esoteric configurations in the cross-compiler or build tool, ability to interactively debug (read the instruction set, use the interface (JTAG, etc), cope with interrupts), ability to thrive with extreme resource limits, and write comprehensive tests with a nearly-exhaustive test plan; since a final release can't be rolled back once customers have purchased it.
This isn't because of some inherent superiority or prestige of embedded systems programming (salaries are lower across the board compared to backend applications programmers), it's just plain more complicated.
A 20-year senior backend programmer should really have progressed to an architect or principal engineer role at that point in her career. An embedded systems developer with 20 years of experience is more typical because of its inherent complexity.