The Clean Coder — Deep Reference

Based on Robert C. Martin, The Clean Coder (2011). Use this when discussing professionalism, estimation, and sustainable pace.

Professionalism

Do no harm — Do not leave the codebase in a worse state. If you must leave a mess, leave a clear TODO and track it. Prefer leaving code better than you found it (boy scout rule).
Know your craft — Practice (e.g., katas), read, stay current. Estimate only what you understand enough to estimate.
Saying no — When a request would compromise quality or is unreasonable, say no. Offer alternatives (e.g., "We can do X by date Y if we drop Z" or "We need two more weeks for tests").
Saying yes — When you commit, mean it. Do not say yes to please and then miss; communicate early if you cannot meet a commitment.

Three-point estimate — Best / nominal / worst case. Use for planning and risk, not as a single "promise" number.
Velocity — Use historical velocity for iteration planning. Do not inflate; if the team goes fast once, use that as data for the next time, not as the new permanent commitment.
Uncertainty — Make uncertainty visible. Prefer ranges and confidence levels over false precision.
Refusal to estimate — It is professional to refuse to give a date when the request is vague or the work is unknown; offer to break it down first or to give a range after discovery.

Sustained overtime reduces quality and long-term output. Occasional crunch may happen; make it rare and recover afterward.
Tests, refactoring, and learning are part of the job. Skipping them to "hit the date" creates technical debt and is unprofessional in the long run.

Code without tests is legacy. Writing and maintaining tests is part of professional delivery, not optional.
When under pressure, the first thing to protect is the test suite and the ability to refactor safely.

Helping others — Part of professionalism is mentoring, pairing, and leaving the codebase (and the team) better than you found it.
Collaboration — Communicate clearly with stakeholders and peers; say no when needed, and offer alternatives when saying yes is not possible.

Use this reference when the discussion involves commitment, estimates, saying no, sustainable development practices, or teamwork.