The fastest teams I have worked with share one habit: they refuse to invent complexity without a deadline-shaped reason. That does not mean avoiding new tools; it means defaulting to stacks that are easy to reason about, diff in review, and roll back when something misbehaves.
On the front end, static typing pays for itself the moment more than one person touches the same module. On the platform side, I bias toward build pipelines I can reproduce locally and deploys that map one commit to one release. When those pieces are boring, the product work gets the attention.
Documentation is part of the stack. Runbooks, ADRs, and a short README at the repo root are not glamour work, but they are what keep a handoff from turning into archaeology. I treat them like tests: incomplete at first, tightened whenever someone asks the same question twice.