Hire a senior SDR when you have no one to build the routine (first hire, new market, no SDR manager) and juniors once that routine exists. In our experience the mix that works is one senior for three or four juniors. Parallel dialing has narrowed the gap on volume; the gap that remains is conversion, and that is what the senior is for.

What "senior SDR" means in Europe

A senior SDR has 18 months or more in the seat, has hit quota for at least two consecutive quarters, and has run a full cadence on a cold list without a manager building it. In France the title is rare because most reps move to AE at that point, so the pool is small and candidates know it.

Do not confuse senior with "has done sales". An ex-AE or an ex-field rep who never ran 180 dials a day is a junior SDR with a higher salary expectation.

The case for juniors

• They stay longer. A junior who sees a written path to AE at 12-18 months commits to the seat. A senior is already looking at the next one.
• No habits to unlearn. The 1,000,000-call benchmark we built with Quentin Despas (Katana) shows 65% of reps open by explaining what they sell. A junior learns the trigger-based opener (7-10% meeting rate against 2-3%) in week one; a senior from a pitch-first culture has to break a reflex.
• Price. In the offers we see from French customers in 2026, a junior SDR in Paris sits around €32,000-38,000 fixed; a senior €40,000-45,000 or more, with a higher OTE.
• Range. Hiring on traits rather than CV opens the pool to career changers, who are often the best reps on the floor two years later.

The cost is ramp. A junior with a written 30/60/90 plan and a dialer from day one reaches full quota in three to four months in our experience. Without those, six or more.

The case for seniors

• Ramp. A senior books meetings in week two. For a team that needs pipeline this quarter, that is the whole argument.
• They build the routine. Two calling blocks, a prepared list with triggers, a handover note the AEs accept. A senior brings this; a junior needs someone to teach it.
• They have survived the dip. Month four, when the first good month is followed by a bad one, is where juniors quit. A senior has been there.
• They free the manager. With a senior running call reviews, the manager's time goes to hiring and territory, not to the basics.

The cost is price, a shorter stay, and the risk of habits from a worse system.

Ramp and output by experience level

Here is what we see on customer teams, as a pattern rather than a survey.

Volume converges fast. With parallel dialing, a junior reaches our north-star of 20 conversations a day within two to three weeks, because the tool sets the pace and the hours are fixed (10am at a 14% connect rate, 4pm at 15.8%). A senior gets there in week one. By month two there is no difference on conversations.

Conversion does not converge on its own. The senior converts conversations to meetings at the trigger-opener rate from day one. The junior starts near the pitch-first rate and climbs with coaching. The gap closes in three to four months when someone reviews calls weekly, and never closes when nobody does.

Acceptance is where seniors earn their salary. AEs accept a senior's meetings at 60-70% from the start. A junior's first month runs lower because they book anyone who says yes. This is the metric to coach, and the one that makes a senior on the team pay for itself.

The mix that works

1. First hire, no SDR manager: senior. They are the manager for the next three hires.
2. Team of three to five: one senior, the rest junior. The senior runs call reviews twice a week.
3. Team of six to ten: promote the senior to team lead, add a second senior, keep juniors at three or four per senior.
4. New country or segment: senior first, always. There is no inbound, no playbook and no one to copy.

The pattern to avoid is five juniors and a sales director who is also closing. Nobody reviews calls, conversion never climbs, and the team is replaced at month twelve.

A decision checklist

• Do you have someone who can run call reviews weekly? No: senior.
• Do you need meetings this quarter? Yes: senior.
• Is the path to AE written and credible? Yes: juniors will stay. No: seniors will leave too.
• Are the dialer, the CRM and a list with triggers ready for day one? No: fix that before either hire.
• Is the budget for one senior or two juniors? Two juniors without a coach is one junior with a bigger bill.

How Sonik approaches ramp

Sonik shortens the part of ramp that depends on the tool. Parallel dialing puts a junior at 20 conversations a day in the first weeks, and the signals layer hands them a list with a trigger per contact, so the opener problem is half solved before the first dial.

The coaching layer then shows the manager the gap that remains: opener type, "how" questions, objection handling and AE acceptance per rep. A senior reviewing a junior's week sees the two calls to replay rather than guessing from a dial count.

Conclusion

Seniors buy time and a routine; juniors buy tenure and range. Hire the senior first when nobody can coach, then fill with juniors at three or four per senior. This week, check whether anyone on your team reviews calls weekly. If the answer is no, that is the profile of your next hire, whatever the title says.