How do I justify a fixed fee to a procurement team used to day rates?

A day rate can only be compared to another day rate, never to a commitment on an outcome. The useful question is not what a day costs, it is who pays for the overrun, and on a fixed fee the contract answers it: we do. A technical due diligence engagement gives your procurement team the estimate with its assumptions written out, so they can contest it line by line before anyone is committed to anything.

What stops you cutting corners, since the price is fixed?

Three things, and the third is the one that matters. The scope and the acceptance criteria are written before signature, so a deliverable that falls short is visible and gets reworked. The documented exit is part of the contract, and rushed work is legible in an architecture document. And there is a record: across every engagement since 2019, no client has called us back in an emergency after a handover. That record is our main commercial asset, which is exactly why we protect it.

What if the requirement changes mid-engagement?

We price it, and you decide. A change of scope produces a priced amendment, itself at a fixed fee, which you are free to refuse. What does not exist is silent drift: extra days appearing on an invoice without a decision from you.

Does French law really apply if we contract from the United States?

Yes, in the standard terms, and it is the one clause that genuinely differs from what you may be used to. It is negotiable on engagements where it matters enough to raise. What would not be honest is to bury it in a page nobody reads and let you find it during redlines, so it has its own section in the terms rather than a footnote.

Cœur du Web, fixed-fee technology work, Paris, since 2019

We carry the risk. Here is what that means, line by line.

Four commitments that go into every contract, each with the thing it does not cover. Who pays when an estimate is wrong. How a price gets set. What we turn down, and where we send it instead. Written down before a buyer has to ask for it, because being asked is the slow way to find out.

Ask for the contract Read the terms in full

What is signed

Four commitments, and what each one does not cover.

The third column is the one that took the longest to write. A page that lists only promises reads like marketing; a page that names the edge of each promise reads like a contract, which is what this is meant to be.

01
Fixed fee, and the two exceptions we publish

What is written

Scope, schedule and price are set before signature. No day rate, no counter of days. Two exceptions, and we publish them rather than let you discover them: a two or three day expert audit is billed by the day, because it is exploratory and its scope cannot be fixed before anyone has looked; and where a procurement framework only admits time and materials, we adapt, with a written cap and a defined exit.

What it changes for you

An estimate that turns out wrong is our problem, not a change order three months in.

The limit

A fixed fee needs a scope. A subject nobody can describe yet gets scoped first, in a short paid engagement, and priced after.
02
The delivery risk sits on our side

What is written

Contractual commitment on scope, schedule and quality. Where data moves, an explicit commitment on no data loss: if data is lost through something we did, restoring it is at our expense.

What it changes for you

The question a buyer needs answered is not what a day costs. It is who pays for the week nobody planned. The contract answers it, and the answer is us.

The limit

A fixed price and a commitment on outcome are two different subjects. Everything above commits us on the deliverable. None of it promises a business result: not revenue, not adoption, not a hire you make afterwards.
03
You own everything at the end

What is written

On delivery and payment in full: the source code written for you, the content produced for it, the credentials to every third-party tool. Ownership, not a licence.

What it changes for you

You can hand the work to your own team, or to another provider, the day after we leave. Nothing gets renegotiated at the worst possible moment, because it was settled at the best one.

The limit

We keep authorship attribution, and unless agreed otherwise we may name you as a reference. Both are in the terms.
04
The exit is designed at the start

What is written

Architecture documentation, one person on your side trained during the engagement rather than in its final week, and a decision log explaining why each significant call was made.

What it changes for you

On the day we leave you can run it without us. That is the point, and it is also why our engagement count does not climb fast.

The limit

Trained means able to run it and change it. Not able to rebuild it from nothing: a week of handover makes nobody the author of a system.

The question behind every other question

Who pays when the estimate is wrong?

Every estimate is wrong by some amount. The only thing that varies between providers is whose budget absorbs it, and almost nobody puts that in writing on a website.

Network cabinet with organised cabling — An overrun is rarely a spreadsheet problem. It is a system nobody had fully looked at before quoting.

Time and materials: Every extra week is invoiced. The overrun is on your side.
Fixed fee: The line does not move. The gap is at our cost, in the contract.

Two exceptions are published rather than discovered along the way: a two or three day expert audit is billed by the day because it is exploratory, and a procurement framework that only admits time and materials, with a written cap and a defined exit. The four commitments, with the limit of each.

Compared to the other ways of buying this

The same need, bought four different ways.

Not compared on price. A day rate can only be compared to another day rate, and this table is about what happens structurally when things go wrong, which is the part a rate card never tells you.

Criterion	Fixed fee, with us	Staff augmentation	An independent contractor	Hiring in-house
Who carries a wrong estimate	We do, in writing.	You do. Every extra week is billed.	You do, and usually without a written cap.	You do, plus the salary while the role ramps up.
Who you actually get	The person you met at the first call is the person who scopes it, signs it and runs it.	Assigned according to bench availability, and reassigned the same way.	Exactly who you interviewed, on one skill set.	Whoever accepts the offer, in three to six months.
What happens when they leave	Documented handover and a trained person on your side, written into the contract at signature.	A replacement from the bench, and the ramp-up is on your schedule.	Whatever was in their head leaves with them.	Notice period, then a hiring cycle.
How fast it starts	Work begins within five business days of signature.	Fast, once the framework agreement exists.	Fast, if they are available.	Three to six months, if the search succeeds.
Where it is the wrong answer	A permanent role with no exit. We say so, and point you to a hire.	Nothing, if you can direct the people you rent.	Nothing, for bounded work on one technology.	Nothing, if the work is permanent and you can wait.

Three of these four columns are the right answer for some situations, and we say which on the first call rather than after a proposal.

Pricing

How a price is set, and why there is no rate card.

A price comes out of a short paid scoping engagement, not out of a grid. It fixes the scope, the acceptance criteria and the schedule, and it produces a document with its assumptions written out, so your procurement team can contest the estimate line by line before anyone signs anything.

That document is yours even if you stop there, and it is written to be usable by any provider, including a competitor of ours. If you do continue with us, its cost comes off the engagement.

You will not find a figure anywhere on these English pages, and that is a decision rather than an oversight. Our published prices are set in euros excluding French VAT, a notion that does not translate to a market where sales tax varies by state. A converted number carrying French tax wording would mislead more than it would inform, so scoping is quoted instead.

What never happens

A free proposal built on guesses, sent within forty-eight hours of a first call.
A day rate quoted before anyone has seen the work it is supposed to cover.
Extra days appearing on an invoice without a decision from you.
A price that depends on how urgent your problem sounded on the phone.

The reasoning behind the fixed fee, including what it costs us, is set out at length in the scoping engagement.

The record

The record covers every engagement, not only the fixed-fee ones.

Reviewed in July 2026, across every engagement run since 2019: no client has called us back in an emergency after a handover, and the only three amendments signed after delivery extended the warranty and widened the handover. None of them repaired anything.

One honest caveat, because the dates matter. The firm has worked since 2019, but moving every engagement to a fixed fee dates from 2026. The record above is therefore wider than the model: it covers the engagements that came before the change too.

A working notebook open on a table, next to a laptop

Where we say no

Six requests we turn down, and where they should go instead.

Few engagements get signed in a year, which is what makes it possible to commit on each one. A list of exclusions is also the cheapest way to tell whether a provider knows what they are for.

Small development work taken as it comes, priced by the day

A freelance marketplace such as Upwork or Toptal
A brochure website, with no thought given to the tools behind it

A web agency, or a site builder
A project handed over and then never looked at again

A provider who owns that model, with the schedule trade-off it carries
An annual budget smaller than the cost of scoping the work properly

Well-chosen off-the-shelf tools, without custom integration
Permanent structural reinforcement, rather than an engagement with an exit

A hire, or a long-term partnership
An AI project decided before anyone looked at the actual work

Scoping first. Each wave has to recover more value than it costs, and that gets measured

In every one of these cases you will hear it on the first twenty-minute call. No proposal left sitting in a drawer, no commercial follow-up afterwards.

Read this one properly, do not skim it

One clause genuinely differs if you contract from the United States.

Our contracts are governed by French law, and if a dispute cannot be settled amicably the competent courts are those of Paris, where the company is registered. Everything else on this page travels without difficulty. That clause does not.

It is negotiable on engagements where it matters enough to raise, and raising it is a normal thing for a buyer to do rather than a difficult one. What would not be honest is to leave it in a page nobody reads and let you discover it during redlines.

While we are being straight about the awkward parts: we have no United States client list yet. The work itself travels, and one of these engagements delivered national infrastructure on another continent, but if a domestic client roster is a requirement for you then we are not the right fit for this one.

The full terms, including that section

For your procurement file

Seven things procurement asks for, answered before the question.

None of this is new information. It is the same content as our terms, arranged in the order a buyer actually works through it, so this page can be forwarded internally on its own.

01 A written quote comes first: Valid for thirty days. Nothing starts on a handshake with the paperwork to follow.
02 Service levels, in the standard agreement: Work begins within five business days, support responses within forty-eight business hours, a critical defect addressed within twenty-four. Tightened contractually where your situation needs it.
03 Insurance, with the insurer named: Professional indemnity and general liability cover with AIG. Certificates come with the contract, not after a chase.
04 Liability, and its cap: Capped at the amount invoiced for the engagement. Indirect consequences are excluded, including lost business and changes third-party vendors make to their own products.
05 Confidentiality: Confidential by default, and we sign a formal non-disclosure agreement on request without treating the request as distrust.
06 Compliance documents for your own file: The standard French set, on request: tax and social security clearance certificates, and a current company registration extract.
07 How it ends: A fixed-scope engagement ends on a material failure to perform, after formal notice left thirty days unremedied. A monthly one ends at the close of any period, with a month of notice. No cancellation penalty, no automatic renewal.

Who signs it, and who does the work

The person you meet at the first call is the person who scopes the engagement, signs it and runs it.

Laurent Tulpan: Software engineer. Twenty years alongside the IT departments of a French ministry, of CFAO and of Expertise France. He scopes the engagement, commits the firm to the estimate, and runs it.
David: Builds. Development, integration, production releases.
Clairmont: Builds as well, and takes over when two engagements run in parallel.
On surge: A network of vetted senior profiles, on peaks only. Never a junior presented as a senior.

His track record

What buyers ask

Four questions, answered without hedging.

How do I justify a fixed fee to a procurement team used to day rates?

A day rate can only be compared to another day rate, never to a commitment on an outcome. The useful question is not what a day costs, it is who pays for the overrun, and on a fixed fee the contract answers it: we do. A technical due diligence engagement gives your procurement team the estimate with its assumptions written out, so they can contest it line by line before anyone is committed to anything.
What stops you cutting corners, since the price is fixed?

Three things, and the third is the one that matters. The scope and the acceptance criteria are written before signature, so a deliverable that falls short is visible and gets reworked. The documented exit is part of the contract, and rushed work is legible in an architecture document. And there is a record: across every engagement since 2019, no client has called us back in an emergency after a handover. That record is our main commercial asset, which is exactly why we protect it.
What if the requirement changes mid-engagement?

We price it, and you decide. A change of scope produces a priced amendment, itself at a fixed fee, which you are free to refuse. What does not exist is silent drift: extra days appearing on an invoice without a decision from you.
Does French law really apply if we contract from the United States?

Yes, in the standard terms, and it is the one clause that genuinely differs from what you may be used to. It is negotiable on engagements where it matters enough to raise. What would not be honest is to bury it in a page nobody reads and let you find it during redlines, so it has its own section in the terms rather than a footnote.

Next step

Twenty minutes, and you will know what we would sign.

Describe the situation on your side. We will tell you plainly whether a fixed fee makes sense for it, and if a hire or a provider in your own timezone would serve you better, we will say that instead.

Ask for the contract Take the twelve-question assessment

Where to go next

Service

We carry the risk. Here is what that means, line by line.

Four commitments, and what each one does not cover.

Fixed fee, and the two exceptions we publish

The delivery risk sits on our side

You own everything at the end

The exit is designed at the start