Buyer guide
How to choose an AI development agency.
By ZappientUpdated 6 min read
The short answer
Pick an agency that proves results on your own data before you commit to a big build. Ask who writes the code, how they test quality and who owns the result. Fixed scopes and a short first phase keep your risk low.
Start with the job, not the vendor
Before you talk to anyone, write down one job you want AI to do. Name the tools it touches and how often it happens.
Then add one number that would mean success. For example, half of refund emails answered without a person.
This turns every sales call into a real test. A good agency will push on that number. A weak one will talk about models instead.
Ten questions to ask on the first call
Good answers are specific. Vague answers are a warning sign.
- Who will write the code, and will I meet them before we sign?
- Can you show me a system you built that is live today?
- How will you test quality before and after launch?
- What happens when the AI is unsure or wrong?
- Where will my data live, and does it train any model?
- Is the price fixed, or billed by the hour?
- How soon can we test something on our real data?
- Who owns the code, prompts and test sets at the end?
- Which models will you use, and can we switch later?
- What will it cost to run each month after launch?
A simple scorecard
Use this table to compare agencies after each call.
| Topic | Strong answer | Weak answer |
|---|---|---|
| Who builds it | The people on the call write the code. | A team you meet after signing. |
| Proof | A live system and a reference you can call. | Slides and a demo on sample data. |
| Quality | Test sets, scores and live monitoring. | We check it by hand before launch. |
| Data | Stays in your cloud. Never used for training. | It is safe, trust us. |
| Ownership | You own the code, prompts and tests. | Licensed while you pay the fee. |
| Price | A fixed quote for each phase. | Hourly, with no cap. |
| Running cost | A monthly estimate with cost alerts. | It depends. |
Red flags to watch for
- They promise results before they see your data.
- The demo runs on their sample data, not yours.
- Senior people sell the deal. Then a junior team builds it.
- There is no plan for testing, monitoring or cost control.
- They keep the code or lock you into their platform.
- Every answer is a model name instead of a business result.
How AI agencies charge
Most agencies use one of three models. Each one suits a different kind of work.
| Model | How it works | Good for | Watch out for |
|---|---|---|---|
| Fixed price per phase | A set price for a written scope. Quoted before each phase. | Clear jobs with a success number. | The scope must be written down well. |
| Hourly or daily rate | You pay for the time spent. | Open research or an unclear scope. | Costs can grow with no end date. |
| Monthly retainer | A set fee for ongoing work. | Support and steady improvement after launch. | Paying for time you do not use. |
We use fixed prices per phase at Zappient. It keeps both sides focused on the same result.
Agency, freelancer or your own team?
Each option fits a different stage. An agency is fastest for proving value. Your own team makes sense once AI is core to your product.
Read the full comparison