Build vs buy: should you hire an AI automation agency or do it in-house?

For most service businesses under 50 employees, hiring an AI automation agency is faster, cheaper, and lower-risk than building in-house. Build in-house only if you already have a senior engineer with LLM experience and a 12-month roadmap of 10+ automations. The honest middle path - agency builds the first 3-5, your team maintains - fits most companies. Below: a decision tree, the real costs of each path, and the red flags to watch for when hiring.

The decision tree

Five questions, in order. Stop at the first "no".

1. Do you already have a senior engineer with LLM experience on payroll? No → hire agency. Yes → continue.
2. Do you have a roadmap of 10+ automations over the next 12 months? No → hire agency. Yes → continue.
3. Will that engineer have at least 50% of their time available for AI work? No → hire agency. Yes → continue.
4. Is automation becoming a competitive differentiator in your market (i.e. does your moat depend on it)? No → hybrid: hire agency for the first 3-5, internal team takes over. Yes → continue.
5. Are you willing to absorb a 6-12 month ramp time before the first automation ships? No → hybrid. Yes → build in-house.

The number of service businesses that pass all five questions is small. Most should hire an agency or go hybrid. That is the honest answer, and we make less money saying it - but it is correct.

In-house: the realistic numbers

A senior AI engineer in the Nordics or Western Europe costs €80,000-150,000/year fully loaded. Add €20,000-40,000 for tooling, infrastructure, and training. First automation ships at month 3-4. By month 12 a senior engineer can typically deliver 6-10 production automations if they are not interrupted by anything else. Realistically they get interrupted by everything else, so 4-6 is more honest.

See AI automation cost in 2026 for the full breakdown of in-house vs agency line items.

Agency: the realistic numbers

A focused 60-90 day engagement covering 3-5 automations runs €20,000-50,000. First automation typically ships in week 3-6. Run cost €100-500/month total across all automations. Maintenance retainer (optional) €1,500-4,000/month. Total first-year cost typically lands in the €30,000-70,000 range, including run costs and a light retainer.

Compare to €100,000-190,000 for in-house in the same period. The agency cost is roughly 1/3 for the first year, and that is when in-house is the slowest and riskiest.

Hybrid: the path most companies actually want

Hybrid means the agency ships the first 3-5 automations in 60-90 days with full documentation, source code, and a handover session. Your existing technical team - even a generalist developer - takes over maintenance and small improvements. The agency comes back twice a year for new builds and architecture reviews.

This works because the build phase needs specialist judgment (which prompts to use, where to add fallbacks, how to monitor), but maintenance is mostly normal software engineering. A competent backend developer can keep an automation running once it is properly built.

Cost shape: €20,000-40,000 for the build, then €0-2,000/month for the internal team to maintain (depending on whether you already pay them). Total first year: €25,000-60,000. Second year: €15,000-30,000.

Red flags when hiring an agency

• No written scope before contract. Insist on a one-page scope document with deliverables, timeline, and success criteria.
• "We use proprietary AI." Most agencies are wrappers around OpenAI, Anthropic, and open-source models. That is fine. The proprietary work is the integration and prompt engineering, not the model itself.
• No demos of past work in your industry. AI for legal looks different from AI for logistics. Ask for references.
• Vague pricing without ranges. A serious agency can give you a range in the first call.
• No answer to "what if we end the engagement?" The answer should be: documented handover, source code is yours, monitoring is yours, no lock-in.

Want a second opinion before deciding?

We offer a free 30-minute consultation where we walk through your specific situation and tell you which path fits - even if that path is "hire someone in-house, do not hire us." Honest answers are cheaper to give than wrong contracts. See the consultations page for what is covered, or browse the pillar - 50 real AI automation systems - to see what we have shipped.