Asking a staff engineer to challenge an estimate

A review that asks if an estimate looks right invites a polite yes. Ask them to attack the assumptions, list what you already considered, and say which kind of no you want.

2 min read

You have a number. You want a staff engineer to tell you if it is foolish. The note you send is the number and "does this look right?" They have twelve of those a week. The cheap safe answer is a yes you will later treat as a sign-off.

You do not want a yes. You want a specific no, or a yes that survived one.

Ask for the attack, not the blessing

Choose a review shape. "Please try to break the estimate. I want one of: the number is wrong and here is why, the shape of the work is wrong, or we should not do this. A thumbs-up is only useful if you also say which assumption you accepted."

That is an ask a careful person can spend twenty minutes on. A vibe is five seconds and a later incident.

Put every premise on its own line

Estimates fail in the hidden clause. "Four weeks, since the vendor API is stable" contains a plan and a hope. State the hope as an assumption they can answer no to.

  • The vendor sandbox matches production.
  • We will not need a migration of existing rows.
  • One engineer, no on-call rotation in that month.

If an assistant helped you build the number, it will have invented some of these. Mark which you were told, which you guessed, and which the model inferred. A staff engineer can only challenge what they can see.

List the options you already killed, one line each. Otherwise they will spend the twenty minutes on week one.

Close with a decision you will actually take

Ask for a decision if you need one: proceed on this number, pad it, or stop. Your recommendation, and the fact that would flip it. A default: "If I have not heard by Thursday 17:00 UTC I will treat the number as unreviewed and I will not cite it outside the team."

That default is the honest one. Silence is not a blessing. Dressing it as one is how estimates become folklore.

You approve the package. Point at the design; do not attach it. If they have an account, you need an accepted contact. If they do not, they get email and a page. You do not need them in the same planning tool.

Use their name. A private nickname does not belong on a review they will file.

If the number came out of a session, connect your assistant and have it list the premises before you send the number.

Tags work teams reviews engineering

Frequently asked questions

How do you ask a staff engineer to poke holes in an estimate?
Say you want the assumptions attacked, not a blessing. List each premise on its own line, list the options you already rejected, and name the kind of no you want — the number is wrong, the shape is wrong, or the work should not happen. Looks right is a failed ask.
Why do estimate reviews come back as LGTM?
Because a senior person with little time will not invent a review you did not scope. A vibe check is cheap to give and expensive to trust. Six months later the number is cited as blessed.
Should I hide the number until they have read the work?
No. Hide the premises and they will review the number. Show the premises and they can review those. The number without the assumptions is the thing you already know is weak.

Related articles