The decision between an in-house dev team and an agency can mean €100,000+ per year depending on your company’s stage and needs. The myth “an agency is more expensive” doesn’t hold up - companies doing <40 hours of development per week almost always lose money on an in-house team due to hidden costs (office, tools, unused capacity, HR). An in-house team becomes rational only at 80+ hours/week and a strategic long-term vision. For most SMBs, an agency is the financially and operationally better choice for the first 3-5 years.
This article breaks down the real costs of both approaches, the stages where each pays off, and hybrid approaches that often produce the best result.
What an in-house senior developer actually costs
Typical annual cost of a senior developer isn’t just the salary:
| Item | Monthly (€) | Yearly (€) |
|---|---|---|
| Net salary | 2,000 - 4,000 | 24,000 - 48,000 |
| Taxes and contributions (about 70-80% on top of net) | 1,500 - 3,000 | 18,000 - 36,000 |
| Hardware (laptop, monitor, peripherals) | 100 | 1,200 |
| Software licenses (IDE, tools, AI subscriptions) | 100 - 300 | 1,200 - 3,600 |
| Cloud / hosting for development | 100 - 300 | 1,200 - 3,600 |
| Education and conferences | 100 - 300 | 1,200 - 3,600 |
| Office (per person, if you have one) | 200 - 500 | 2,400 - 6,000 |
| Bonuses and benefits | 200 - 500 | 2,400 - 6,000 |
| Total | 4,200 - 8,900 | 51,600 - 108,000 |
Plus hidden costs:
- HR time for hiring, payroll, reviews (€500-€2,000/month)
- Leadership time managing technical decisions (€500-€3,000/month)
- Fluctuation risk (departure, vacation, sick leave, parental leave)
Real annual cost per senior: €60,000-€130,000 in the region.
What an agency actually costs
An agency offers the same senior developers in a different model:
| Model | Monthly | What’s included |
|---|---|---|
| Per hour | €60-€90 / hour | Actual hours worked on the project |
| Monthly retainer (full-time equivalent) | €6,000-€12,000 | Team on standby, flexible per project |
| Fixed-price projects | €5,000-€80,000+ | Full project with fixed scope |
What an agency covers (included in the price):
- Senior developer (top quality)
- Project manager / coordination
- QA / testing
- DevOps / hosting infrastructure
- Designer (if needed)
- Backup developer (if the first one is on vacation)
- Hardware, software, office - all the agency
Real monthly cost for full-time agency work: €6,000-€12,000. For part-time (20-40 hours/week): €2,500-€6,000/month.
When in-house pays off, when an agency does
The most important variable: how many development hours you actually need.
Less than 20 hours/week - agency is better
A half-time senior developer isn’t realistic. They expect a full-time position or leave. The agency only bills hours actually worked.
A typical SMB in the first years of software projects - 1-2 days of development per week is enough.
20-40 hours/week - agency usually better
The threshold where in-house starts being an option, but rarely the cheapest. An in-house junior + agency for seniors is often the optimal hybrid.
40-80 hours/week - think carefully
This is where in-house starts to pay off, but only if you have all the needed roles (dev, QA, devops, design). Often a hybrid of 1-2 internal developers + agency for specialized work is best.
80+ hours/week - in-house is a serious option
The stage where a cohesive in-house team gives the best economics and strategic context. But even then the agency has a role for specific skills (e.g. specialized AI work, security audit).
Hybrid approaches - often the optimal economy
Three combinations that often work great:
1. “Technical partner” model
What: You have 1-2 internal developers who understand your business domain. A dev agency is the technical partner for everything bigger.
Best for: SMBs with 50-200 employees seriously investing in software but without a full technical team.
Cost: €100,000-€250,000 annually (combination of salaries and agency retainers).
2. “Build and transfer” model
What: The agency builds the first MVP and early versions. During that, gradually transfers knowledge to your internal developer. After a year or two, the internal team takes over.
Best for: Startups and younger companies that want their own team but can’t start one themselves.
Cost: First year - €120,000-€200,000 (mostly agency). Gradually decreases.
3. “Capacity overflow” model
What: You have a complete internal team. The agency helps during spikes - new product, urgent expansion, specialized work.
Best for: Larger companies (100+ employees) with stable internal teams.
Cost: Variable - as needed.
What an internal team brings that an agency can’t
Honest about in-house advantages:
- Deep business understanding. An internal developer learns your domain over years. An agency works for 10 clients.
- Closer communication with other departments. An internal team has coffee with salespeople, hears the real problems.
- Long-term strategic vision. An internal CTO thinks in years, not projects.
- Asset character. An internal team is part of the company, gives value stability.
For companies that view software as a strategic asset (tech-first, B2B SaaS, fintech) - an in-house team is mandatory.
What an agency brings that an in-house team can’t
And honestly about agency advantages:
- Broader expertise. An agency has senior frontend, senior backend, mobile, devops, designer. An in-house team struggles to hire everyone.
- Has already solved the same problem. An agency has done 50 similar projects. An in-house team does it for the first time.
- Fast scaling. Need 5 people for 3 months? An agency has them tomorrow. In-house: 6 months of hiring.
- No HR risk. Termination, sick leave, vacation, parental leave - the agency handles it all.
- Lower initial investment. No HR setup, office, hardware, tools.
5 most common decision mistakes
1. “Having our own developers is prestigious.” It’s not about prestige, it’s about economics.
2. Hiring juniors without a senior to lead them. Without a senior mentor, juniors build technical debt faster than they produce results.
3. Outsourcing on price alone. “Indian team for €15/hour” - often more expensive than a quality EU agency at €70/hour due to endless rework.
4. Premium treatment for in-house, ignoring the agency. Internal team gets priority, agency is only “when needed.” That way you lose architectural coherence.
5. No knowledge transfer plan. If the agency leaves, the in-house team doesn’t understand the code. If the internal developer leaves, the agency doesn’t know where they stopped. Documentation is mandatory.
Frequently asked questions
We have €3M in revenue - do we need our own development team? Depends on how much software works for you. If software is the main product (SaaS) - yes. If software supports the business (e.g. internal tools) - usually no, an agency is enough.
What if the agency leaves and we’re stuck? A real development partner has a contract with a clear handover mechanism. Code in your repo, documentation accessible, a new partner can take over in 2-4 weeks. Without a plan - the risk is real.
Can we embed a senior developer from the agency in our team? Yes, many agencies offer an “embedded developer” model - a dev engineer works exclusively for one client for several months. Cost: €8,000-€15,000/month.
Who manages architecture in a hybrid model? Most often a Tech Lead from the agency + one senior internal developer. Decisions made together. Without clear responsibilities, architecture becomes chaos.
Thinking about your software approach?
Book a free Discovery call. We review your current situation - size, growth plans, project types - and propose a realistic model that pays off economically and operationally for the next 2-3 years.
Reach out at [email protected] or through the form on our homepage.