The short answer
How the two options compare
| Agency | In-house team | |
|---|---|---|
| Time to start | Weeks. | Three to six months to hire and ramp. |
| Cost per hour | Higher. | Lower once productive. |
| Total cost of stopping | Notice period. | Redundancy, or carrying the cost. |
| Breadth of skill | A team: ML, data, infrastructure, product. | Whatever you hired for. |
| Knowledge retention | Leaves with the contract unless handover is contracted. | Stays, until the person does not. |
| Ramp on your domain | Weeks, and repeated per engagement. | Deep, and compounds. |
| Hiring risk | None. Replacements are the agency’s problem. | Yours. A bad hire costs six months. |
| Best for | A defined push, or the first one. | A permanent capability. |
When an agency is the right call
- You have not built AI before. The first project is where the expensive mistakes live. Buying experience for it is cheaper than making them.
- The work has an end. A defined build with a defined outcome does not need permanent headcount.
- You need several skills briefly. A production system needs ML, data engineering, infrastructure and product judgment. Hiring four people for one project is not sensible; hiring one and hoping is worse.
- You do not yet know what to hire for. One delivered project tells you exactly which permanent role you need, which is a far better basis than a job description written in advance.
When hiring is the right call
- AI is becoming part of the product. Anything shipping continuously needs people who are there continuously.
- The domain takes months to learn. In clinical, legal or heavily regulated work, domain knowledge is most of the value, and it compounds in a person who stays.
- You already know what you are building. If the roadmap is clear and the work is permanent, in-house is cheaper within a year.
- Data cannot leave. Where the constraints genuinely rule out outside access, the decision is made for you.
What the business case usually misses
On the in-house side
Recruitment cost, the three to six months before someone is productive, benefits and equipment, and the risk that the roadmap changes before they arrive. Machine learning engineers are also among the hardest roles to hire and among the easiest to lose, and a team of one is a single point of failure with a notice period.
On the agency side
The ramp on your domain, repeated each engagement, and the knowledge that leaves with the contract unless handover is written into it. An agency that does not hand over documentation, tests and a named internal owner has sold you a dependency rather than a system.
What does the hybrid look like?
It is the most common answer and it works in one direction: the agency builds the first system and hands it over, while you hire the person who will own it, and the two overlap deliberately. You get speed without the knowledge walking out, and your first hire arrives to a working system rather than to a blank repository and a mandate.
Is an AI agency more expensive than hiring?
Per hour, yes. Over a defined project, usually not, once recruitment, ramp and the risk of hiring the wrong specialist are counted. Over three years of continuous work, in-house is cheaper and you should hire. We will tell you when that point has arrived, because an agency that will not is an agency selling you a permanent arrangement you have outgrown.
Related
- How IT staff augmentation is priced: what to compare beyond the hourly number.
- IT staff augmentation: the option between the two, where engineers work inside your team and your process.
- Engagement models: how each way of working is actually structured.
- AI glossary: the vocabulary a first hire will be expected to know.
