A ninety-day replacement guarantee can be worth less to you than a thirty-day one. The guarantee is a promise to source again at no new fee; it does not refund what you have paid and it does not give back the calendar. The number of days is not the thing to read first. Three other lines decide what a window is actually worth: which day it starts counting, what has to happen inside it, and what the rest of the contract charges you for the longer headline.
Which day does the clock start
Thirty days from what? Signature, the engineer's first working day, or the day your access requests cleared? Signature to first commit is rarely the same day once laptops, SSO and VPN are involved, so a window that opens at signature is shorter than the headline says. First working day is the only start that measures what you are actually evaluating.
Ask rather than assume, because many clauses do not say at all, and where the paper is silent the absence of that sentence is itself information. Ours names the first working day.
And when does it stop
The stop condition matters as much as the start. Clauses come in two forms: one requires you to raise the problem inside the window, the other requires the replacement to have started inside it.
The second is much harder to satisfy, because sourcing takes time you do not control. A window that closes only when a new person is at a keyboard can expire while you wait on the vendor's pipeline. You want the obligation to be yours: you flagged it in time, therefore it applies.
Why ninety can be worse than thirty
The windows to read are fourteen, thirty and ninety days, and they do not simply improve as they lengthen.
- Fourteen days. Long enough to see the signals that predict a bad engagement, not long enough to act on them.
- Thirty days. One decision cycle — long enough to judge, short enough that the vendor still carries the consequence of its own screening.
- Ninety days. The best headline, and the one to read hardest, because a long window is often paid for with something else in the same document.
That trade is the whole point. Read the term, the notice period and any early-termination fee before you read the guarantee, because a ninety-day window inside a twelve-month minimum is worse for you than a thirty-day window month to month. In the second case your exit never depends on the guarantee at all: you give notice and leave, in month two or month nine, for a reason you do not have to argue. In the first, the guarantee is the only door in the building, and it closes on day ninety.
So on month-to-month terms with symmetrical thirty-day notice, the notice clause is your protection; the guarantee only decides who absorbs the cost of trying again.
What a guarantee never covers
Take these line by line against your own draft.
- The engineer resigning. A fit clause and an availability clause are different things, and the words "replacement guarantee" only promise the first. Check whether your contract names both, and what the second one is called, because that is the clause you will need in month four.
- A refund. Read it rather than assume: the days worked are normally written as due, because work was done and someone was paid for it. "Free replacement" means free sourcing, not money back.
- Your own change of scope. You hired a React engineer and moved the roadmap to data pipelines in week three. That is a re-brief, not a failed hire, and a vendor may treat it as one.
- A second attempt. Check whether the clause covers one replacement or applies again to the replacement. If the second person also misses, you want to know today what the paper says, not then.
- The gap. No contract returns the weeks between "this is not working" and "the new person is productive." A replacement needs however long the first one needed to become useful, and that time is billed twice unless the contract says otherwise.
Two of those are argued at length elsewhere rather than repeated here: what the trigger should say — your judgment, not documented cause — and who carries the second ramp-up, both in the piece on engagements that do not work out, with the early signals that let you use a window while it is open. The ramp itself is in the onboarding guide.
The questions, in writing
- Does the window start at signature or on the engineer's first working day?
- Must I raise the problem inside the window, or must the replacement have started inside it?
- What minimum term, notice period and early-termination fee come with this window?
- Does the guarantee apply again if the replacement also misses?
- What happens if the engineer resigns in month four, and what is that clause called?
- How many business days to the first candidate for my stack?
Six lines in an email. The answers are the product, and the speed of the reply is part of them.
What ours says, and what it does not
Thirty days, not ninety, and the clause is published in full so you can test this reading against it. It says that if the engineer is not a fit in the first thirty days the studio replaces them at no additional cost, that the days the first engineer worked remain due, and that any overlap while the replacement ramps up is carried by the studio rather than billed on. Resignation lives in a separate clause called Named engineer, which also forbids substituting your engineer without your written approval: if they resign or become unavailable, you hear the day the studio knows, get replacements to interview, and may end the engagement immediately instead of serving notice.
Read those words closely and they answer five of the six questions. The condition is the fit judgment falling inside the first thirty days, not a replacement having started by then. The clause is written about the engagement's first thirty days, so a second miss inside that window reads the same way and one after it does not. Resignation has a name. The term is month to month with thirty days notice either way and no placement or conversion fee, so the exit never depends on the guarantee — the rates sit on the site rather than behind a call. And the first vetted candidates arrive within five business days on common stacks, ten to fifteen on scarcer ones such as Go, iOS or Vue, with HireBrazilDevs saying which yours is before you send the brief.
The three lines above are now in ours, which is the only reason this article can name them without embarrassment: the clause says the thirty days run from the engineer’s first working day, that the Client’s own judgement is the test with no documented cause required, and that the window closes when the Client raises the problem rather than when a replacement has already started. What it still does not promise is a second free replacement if the replacement also misses — ask us, and ask every vendor, because the paper is where that answer has to live. The full text is on the contract page.
The short version
A replacement guarantee buys sourcing, not time and not a refund. Read the start date, the stop condition and the term bundled with the window before you compare the number of days. On month-to-month notice, the clause that protects you is the one about leaving.
Not legal advice: have your own counsel read whatever you sign.