Reduce debt at every opportunity
Don't let technical debt become so burdensome that it hinders work and sanity—follow the Boy Scout rule, "Always leave the campsite cleaner than you found it".
Features, stories, and tasks always have room to reduce debt and increase readability.
Always be threat modeling
Data is a liability. You should consistently be questioning which resources need protection, system boundaries, access capabilities from all sides, and what it would take to feasibly cause a breach.
Dependency Injection is always the answer
There aren't many hills I'd die on, but DI is one I refuse to budge on.
The minor inconvenience of complexity is far out weighed by a code base's ability to be easily manipulated with minimal side effects.
A job done well means not over-engineered
Over-engineering is a complexity that burdens code bases, developers and budgets. We need to encourage each other to solve today's problems, not tomorrows.
Could, would, should
Three powerful words I use consistently in code reviews. No condescending tones, no orders, just simple open ended questions leading the author to reevaluate and stay in control of their code.
Use a coding journal
Every day a number of thoughts weave in and out of our minds. I forgot more than I remember so I take notes: where I left off, TODOs, design decisions, potential issues, follow-ups, action items, thoughts, and so much more.
Trust the note not the memory.
Nesting reduces readability and increases cognitive load. Reduce, or better yet, never nest. Return early and extract code blocks when feasible.
SOLID, KISS, DRY = suggestions, not rules
Extensibility, flexibility and maintainability should be balanced with future effort and developer sanity and onboard-ability.
Often times it is okay to repeat yourself, it is okay to be verbose and straightforward.
Naming is hard
Naming and organization is one of the hardest parts of engineering. A poorly chosen name will haunt your code base for years, don't under think it.