On the other end of the spectrum, I have little software engineering experience but having dabbled in competitive programming, I can solve almost all algorithmi

On the other end of the spectrum, I have little software engineering experience but having dabbled in competitive programming, I can solve almost all algorithmic interview questions optimally within minutes if not seconds. I still failed half of my interviews though (including Google even though I believe I answered every question perfectly). Perhaps it's due to my presentation, or my lacking portfolio, or perhaps the positions have simply been filled. On another note, OP seems to rely on recruiters to approach him? Wouldn't it make sense for OP to actively apply to positions which may have better fit?