Fractional CTO or a development agency?
A fractional CTO decides what gets built, how, and by whom, and holds the builders to a standard. A development agency builds it, fast, against a specification. The CTO costs £6,133 to £10,733 a month at two days a week; an agency bills per engineer or per project. Without somebody technical judging the work, an agency builds exactly what was asked, right or wrong.
Below is what each one actually owns, what they cost on the same basis, how each one fails, and when to pick the other one.
| A fractional CTO | A development agency | |
|---|---|---|
| Who owns the outcome | What gets built, and more importantly what does not | Delivery capacity, now, without a hiring process |
| Commitment | One to three days a week, flexing with the work, no end date assumed | A fixed-price project or a monthly rate per engineer |
| How it is priced | £800 to £1,400 a day | A day rate per engineer or a project fee, typically well above an employed engineer's cost for the same time. |
| Typical monthly cost | £6,133 to £10,733 a month at two days a week | No like-for-like monthly figure is published here; see how it is priced |
| How it fails | Being hired with nobody to build. A fractional CTO who is also the only engineer is just an expensive engineer working two days a week. | Building exactly what was specified when the specification was wrong, which is the single most expensive failure in software and almost always ends in a rebuild. |
| Pick it when | Nobody technical can judge whether what is being built is sound | You know precisely what needs building and it is a defined piece of work |
What a development agency actually is
An external team building the software, usually against a specification, for a fixed price or a monthly rate per engineer.
What each one owns
| A fractional CTO | A development agency |
|---|---|
| What gets built, and more importantly what does not | Delivery capacity, now, without a hiring process |
| Architecture decisions that are expensive to reverse later | A team that has shipped this kind of thing before |
| Technical hiring, and judging who is actually good | Scaling up and down with the work |
| Holding whoever is building to a standard, including an agency | Getting a first version into the world quickly |
What neither of them does
Neither decides what the product should be. That is the founder's job, and no amount of engineering makes up for the wrong answer.
How each one fails
The fractional CTO: Being hired with nobody to build. A fractional CTO who is also the only engineer is just an expensive engineer working two days a week.
A development agency: Building exactly what was specified when the specification was wrong, which is the single most expensive failure in software and almost always ends in a rebuild.
What they cost, on the same basis
A fractional CTO charges £800 to £1,400 a day, which is £6,133 to £10,733 a month at two days a week. A day rate per engineer or a project fee, typically well above an employed engineer's cost for the same time. The monthly and annual arithmetic for the fractional side, against a full-time equivalent, is on the cost page for this seat.
Pick a development agency when
- You know precisely what needs building and it is a defined piece of work
- You already have somebody technical who can judge the output
- It is a genuine project with an end, rather than a product that keeps evolving
We would rather say that plainly than win an engagement that was the wrong shape. Nobody pays us to list on the bench, so there is nothing in it for us either way.
When you want both
The arrangement that works is a fractional CTO above an agency: the agency builds, the CTO decides what and checks it is sound. Companies that skip the second half usually discover the cost of it at the rebuild.
Common questions
Should I hire a fractional CTO or a development agency?
A fractional CTO decides what gets built, how, and by whom, and holds the builders to a standard. A development agency builds it, fast, against a specification. The CTO costs £6,133 to £10,733 a month at two days a week; an agency bills per engineer or per project. Without somebody technical judging the work, an agency builds exactly what was asked, right or wrong.
Is a fractional CTO cheaper than a development agency?
On a like-for-like basis it usually is, because you buy the days you need rather than all of them. A fractional CTO runs £800 to £1,400 a day, most often one to three days a week. A day rate per engineer or a project fee, typically well above an employed engineer's cost for the same time. But cheaper is the wrong question if the work genuinely needs the other one.
When is a development agency the better choice than a fractional CTO?
You know precisely what needs building and it is a defined piece of work. You already have somebody technical who can judge the output. It is a genuine project with an end, rather than a product that keeps evolving.
Can I use a fractional CTO and a development agency at the same time?
The arrangement that works is a fractional CTO above an agency: the agency builds, the CTO decides what and checks it is sound. Companies that skip the second half usually discover the cost of it at the rebuild.