Most comparisons of US recruiting agencies are lists of names with no framework, which is why they are useless when you actually have a role to fill. The firms below solve genuinely different problems, and the expensive mistake is picking the wrong model rather than the wrong brand.
We run one of these, which you should weigh. We have tried to be accurate about where the others are stronger, and said so.
First, work out which problem you have
Three questions decide the answer, and the brand names are downstream of them.
Is anyone good applying? If your posts produce reasonable candidates and the bottleneck is screening time, you do not need an agency — you need a better process and possibly a contract recruiter. If the applications are wrong and have been for months, you have a reach problem, and no amount of screening fixes it.
How senior and how rare? A pool of thousands and a pool of two hundred are different businesses. The second needs someone who already knows those two hundred people.
Does it need to be confidential? Replacing someone who does not know they are being replaced rules out job posts and rules out broad marketplace distribution.
The five models
Contingency recruitment
Who: Insight Global, Robert Half, Michael Page, Aerotek, and a long tail of boutiques.
What they are good at: volume and speed with no risk. You pay only on a hire, typically 20–25% of first-year salary, so you can run several agencies at once. Insight Global operates across 70+ US offices.
Where it falls down: because they carry the risk, contingency recruiters work the roles most likely to close. A genuinely hard search competes with easier ones on the same desk. You also get duplicate outreach into your market when you run four agencies at once, which is worse for your employer brand than most founders realise.
Retained executive search
Who: Korn Ferry, Heidrick & Struggles, Spencer Stuart, Russell Reynolds; Riviera Partners for engineering leadership specifically.
What they are good at: dedicated attention. You pay in instalments, typically 25–35% of first-year compensation, and a consultant works the search whether or not it is easy. They will approach people who have said no to recruiters for years, and they will manage a board process.
Where it falls down: you pay whether or not it works, and it is slow by design. Overkill for a Series A engineering hire.
RPO
Who: Cielo, Korn Ferry RPO, Hudson RPO, PeopleScout.
What they are good at: taking over your recruiting function at scale. If you are hiring 100+ people a year and lack the internal team, RPO is genuinely cheaper per hire than agencies.
Where it falls down: long contracts and slow onboarding. It is an operating decision, not a way to fill one role.
Recruiter marketplaces
Who: Paraform, Hunt Club, 100Networks, and a growing field.
What they are good at: multi-firm reach under one contract. Your role goes to several specialist recruiters at once rather than one desk, and you sign and invoice once rather than four times. Paraform is the largest in the US and works with Palantir, Rippling, Scale and Cursor.
Where it falls down: models vary a lot. Some broadcast to a large network, which is fast but wrong for confidential searches. Ask specifically how confidential mandates are routed.
AI sourcing platforms
Who: SeekOut, HireEZ, Fetcher, Juicebox, and many more.
What they are good at: finding people. Modern sourcing tools genuinely surface candidates your team would never have found, at a fraction of agency cost.
Where it falls down: they find people; they do not convince them. If you have someone who can run outbound conversations well, these are excellent leverage. If you do not, you have bought a list.
What each model costs
| Model | Typical fee | You pay if nobody joins |
|---|---|---|
| Contingency | 20–25% of first-year salary | No |
| Retained search | 25–35%, in instalments | Yes |
| RPO | Per hire or monthly | Depends on contract |
| Recruiter marketplace | 8–25% on hire | No |
| AI sourcing platform | $500–3,000/month | Yes — it is a subscription |
| In-house recruiter | $110–160k fully loaded | Yes |
Then add what the process costs internally: roughly 42 hours of senior-engineer time per role on résumé triage, screens, interviews and debriefs — spent before anyone is hired.
Where we fit, honestly
100Networks is a recruiter marketplace built specifically around candidates who are not applying anywhere. 72% of the people we place were not looking for a job when we found them. Specialist recruiters who have filled that exact seat before work each search, with AI agents handling sourcing, calling and outreach behind them — agents do the reach, people do the convincing. The fee is 8.33% of first-year salary, invoiced on the day the person joins, non-exclusive, with a 90-day replacement guarantee.
Where we are the right call: roles already stuck because the right person is not applying — niche technical seats (robotics, perception, ML, embedded, security, infrastructure), engineering leadership including confidential backfills, and team build-outs on one bar. We work US mandates alongside India and Europe, including US companies building engineering teams offshore.
Where we are not: we are younger and smaller than the firms above — founded in 2025. If you need forty contract engineers onsite in Austin next month, Insight Global will serve you better and we will say so. If your board wants a name on the search, retained is the safer political answer.
How to choose, in one paragraph
If applications are producing good people and you just need help sorting them, buy process, not reach. If you are hiring steadily at volume, build in-house — it is cheaper per hire and better for candidates. If a specific role has been open for months, the pool is small and nobody good is applying, buy outbound: contingency, retained or a marketplace depending on how senior and how confidential. And if a firm tells you they are the right answer for all of those, that is the signal to keep looking.
If a role has been stuck for months and you want a view on whether it is a brief problem or a reach problem, send it to us — we will tell you which, and say so if we are not the right fit.