TL;DR
Hiring a senior AI or forward deployed engineer takes roughly 3 to 7 months before the new person is contributing. The search alone averages 50 days for a full-stack role and 89 days for an AI / ML one. The total is my sum of three cited ranges: search, notice period and ramp-up. While you search, the usual options are contractors, an agency, or an embedded engineer on a subscription. Each trades speed, control and commitment differently, and the last section lists what to check in any of them.
I’m Denys, a senior full-stack and AI engineer in Porto. I work as a forward deployed engineer on a subscription, so weigh my view accordingly. If you have an open FDE or AI engineer role, the calendar is probably your biggest risk, so I collected the numbers. If you are still deciding whether you need the role at all, start with what a forward deployed engineer is and does.
How long does it take to hire a forward deployed engineer?
Three waits stack up. First the search, then the notice period of the person you pick, then their ramp-up. Demand makes the first one worse: Business Insider reported that Indeed postings for forward-deployed engineers in April 2026 were roughly 729% higher than a year earlier. The base was small (Indeed’s economist said the raw total was still in the thousands), but you are competing for the same few candidates as everyone else.
| Stage | Typical time | Source |
|---|---|---|
| Search: full-stack engineer | 50 days | KORE1, 2026 |
| Search: AI / ML engineer | 89 days | KORE1, 2026 |
| Notice period, senior engineer | 2 to 4 weeks in the US, 1 to 3 months in the UK and EU | JobsByCulture |
| Ramp-up to the 10th merged pull request | 33 days on average | DX, April 2026 |
My sum of those ranges: 50 + 14 + 33 = 97 days at the fast end, 89 + about 90 + 33 = about 212 days at the slow end. That is roughly 3 to 7 months.
Read these numbers with care:
- KORE1 is a staffing firm and says in the article that it benefits when companies cannot hire fast enough alone. The same page puts startups under 200 people at about 38 days for tech roles in general, so a lean process helps. The AI / ML figure is still the one to plan around.
- Sources define “filled” differently. Some stop at the accepted offer, some at the start date. Treat the sum as an order of magnitude.
- DX measured companies with 500+ developers, and the 10th pull request is a milestone, not full productivity. DX says so itself.
What does it cost to hire one?
Salary is the visible part. Levels.fyi lists the median total compensation of a senior software engineer in the United States at $250,000, with the middle half between $180,000 and $360,000. That includes stock and bonus, and it was last updated in September 2026. In Europe, Ravio’s October 2025 data puts a senior software engineer’s salary at €111,800 in Germany and £110,200 in the UK. The base ranges that employers post for the FDE title itself are in forward deployed engineer salary.
The second cost is the recruiter, if you use one. Recruiting firms quote 15% to 25% of first-year base salary on contingency, with 20% the common benchmark and 25% to 30% for senior or hard-to-fill roles. Their own example: on a $130,000 salary, a 20% fee is $26,000, due the day the person starts. All published fee figures come from recruiting vendors, because I found no neutral survey.
The third cost has no price tag: months of the founder’s or CTO’s time on interviews, plus the weeks a new hire spends learning your codebase.
How does hiring compare with a subscription?
| Hire an FDE in-house | Monthly subscription | |
|---|---|---|
| Start | About 3 to 7 months (my sum above) | No search and no notice period |
| Commitment | Employment contract, notice, local labour law | Month to month |
| Cost model | Salary and benefits, plus a recruiter fee if you use one | Flat monthly fee |
| Who carries ramp-up | You, in paid months | Inside the monthly fee, though learning your product still takes time |
| Exit | Notice period, possibly severance | Stop at the end of a month |
| Best for | A permanent seat on your team | Shipping while you decide what the role should be |
A full-time employee gives you every working hour. A subscription gives you scoped tasks, so the two are not a one-for-one swap.
When should you still hire in-house?
Hire when the job is bigger than a queue of tasks.
- You need someone permanently on site at your customers’ offices. Subscription work is remote and asynchronous.
- You have steady full-time work for years and want someone to grow into a lead and manage other engineers.
- You need someone reachable at any hour for incidents.
- The role requires clearances, on-site presence or employment status your customers demand.
If you do hire, how do you shorten it?
None of this is magic, but each step removes a wait.
- Define the first 90 days of work before you post the role. Candidates respond to a concrete problem, and you can judge their answers against it.
- Start from the work, not the title. “Forward deployed engineer” covers everything from solutions engineering to production engineering. Describe what the person will ship.
- Use a paid take-home or trial task. A few hours on a real, small piece of your codebase tells you more than another interview round.
- Plan for notice periods early, especially in the EU. One to three months is normal for a senior engineer there, so ask about it in the first call and negotiate the start date with the offer.
- Prepare the first week. Repo access, a first small task and one named person to ask. Ramp-up is shorter when the new hire is not waiting on logins.
What should you check in any contract or subscription arrangement?
Whether you hire a contractor, an agency or an engineer on a subscription, ask the same questions.
- Code ownership. Does the work land in your repository, and are the rights yours?
- Who carries ramp-up. Is learning your product billed, or part of the fee?
- Working-hours overlap. How many hours a day can you reach the person live?
- How scope is agreed. Who writes the task, and what happens when it turns out bigger?
- Exit terms. What does stopping cost, and what do you get at the end?
Choosing between hiring, an agency and a freelancer? I wrote the comparison: forward deployed engineer vs agency vs freelancer.
Comparing notes on an FDE role?
If you're weighing a hire against other options, I'm happy to share what I've seen. No pitch.