TECHNICAL RECRUITMENT · UNITED KINGDOM

Technical recruiters for the UK.

Engineer-vetted shortlists of the top few percent, in 24 to 48 hours. Software, cybersecurity and deep tech, filled nationwide and remotely.

In short

ON3 Works recruits engineers across the UK: a fully remote firm sourcing nationally rather than from one city. AI screens to a qualified shortlist in 24 to 48 hours, then a senior engineer interviews every finalist before you see them. Fees are 7% (Agentic, AI-led) or 20% (Atelier, engineer-vetted), with no deposit, so the Agentic tier often costs less than hiring in-house. You hire the engineer directly; ON3 finds and vets them.

THE UK MARKET

What hiring engineers in the UK actually looks like in 2026

The UK is Europe's deepest engineering market and its most expensive. The pull right now is concentrated in AI/ML, data, cloud and DevOps, and payments infrastructure, and pay reflects scarcity. Based on ON3's index of 1.7M+ UK and Spanish technical profiles, a backend engineer in London sat around £75,000 at the mid-point of the market in 2026, with senior profiles near £95,000 and the top decile above £125,000 in cash.

Speed is the other pressure. The UK average time to hire is about 4.9 weeks, and specialist tech roles often run 6 to 8 weeks in-house [StandOut CV; NatWest Mentor, 2026]. In a market where the strongest engineers are off the table within days, that gap is where good hires are lost. ON3 is built to close it: a qualified shortlist in 24 to 48 hours and a median hire in under 30 days, the same speed across every UK region.

SALARY BENCHMARKS

UK engineering pay, from ON3's dataset

Indicative annual base salary by role and seniority, drawn from ON3's UK profile index. Useful for setting a realistic offer before you open a search.

Role (London)JuniorMidSenior
Backend£31k–48k£64k–101k£79k–121k
Full-stack£32k–45k£45k–75k£70k–100k
ML£38k–54k£52k–95k£86k–142k
DevOps£26k–40k£50k–80k£69k–102k

Source: ON3 Works index of 1.7M+ UK and Spanish technical profiles, refreshed daily (2026). Figures are indicative base salary; London-weighted. Independent aggregators put London backend in a similar range (Glassdoor median ~£79k, 90th percentile ~£128k).

HOW ON3 WORKS HERE

Two tiers, one engineer-led standard

Agentic
7% · AI-LED, FOR SPEED
AI searches, screens, interviews and ranks candidates, then sends a qualified shortlist in 24 to 48 hours. Built for urgent and high-volume roles. At 7%, often cheaper than hiring in-house.
Atelier
20% · ENGINEER-VETTED, FOR CRITICAL ROLES
Everything in Agentic, plus a senior, domain-matched engineer (8 to 15+ years in that stack) who interviews every finalist before they reach you. For roles where a wrong hire is too costly to risk.

Both tiers run on the same UK-wide sourcing and the same engineer-led quality bar. A precise note on the 24 to 48 hours: that shortlist is AI-screened and qualified, not yet engineer-interviewed. In Atelier, the senior-engineer interview follows before any candidate reaches you. No deposit, billed in GBP, with a free replacement inside 90 days.

ROLES WE FILL

Software, cybersecurity and deep tech

ON3 built its reputation in software and is now growing fast in cybersecurity and deep tech, including chips and HPC, which is a particular UK strength. Common UK searches:

  • Backend
  • Full-stack
  • ML / AI
  • Data
  • Platform
  • DevOps / cloud
  • Frontend / React
  • Cybersecurity
  • Engineering leadership
PROOF

Who ON3 hires for in the UK

The pattern is two kinds of buyer. Teams tired of traditional agencies charging a fortune for work they could do themselves come to ON3 for genuinely rigorous, technical vetting: profiles that are fully checked and actually fit the brief. And teams under urgent pressure, who never used agencies because of cost, try the Agentic model at 7%. In the UK specifically, quality tends to weigh even heavier than speed.

One example: a YC-2023 company that raised a Series B in 2026 used ON3 to hire 12 technical staff, working through ON3's venture-capital channel to find qualified candidates fast. CGI, the global consultancy, uses ON3 for 50+ hires a year and operates in the UK as well as Spain.

ON3 Works has become my favourite external recruiting partner. They're fast, efficient, and bring us candidates already vetted, qualified, and ready to hire. They've made talent search easy for me and my team.

Gabriel Garcia, Vice-President Consulting Services, CGI

24–48h
To a qualified UK shortlist
90.7%
Retention at 12 months
1.7M+
UK & Spain profiles, refreshed daily
QUESTIONS

UK hiring FAQ

How much do technical recruiters charge in the UK?+
ON3 charges a percentage of first-year salary: 7% for the AI-led Agentic tier and 20% for the engineer-vetted Atelier tier, no deposit, billed in GBP. Traditional UK tech agencies typically charge 18% to 22%, so the Agentic tier usually comes in below the market and often below the real cost of hiring in-house.
How fast can you fill a backend role in the UK?+
ON3 produces an AI-screened qualified shortlist in 24 to 48 hours and reports a median time to hire under 30 days. For comparison, the UK average is around 4.9 weeks, and specialist tech roles often take 6 to 8 weeks in-house.
Do you cover the whole UK or just London?+
The whole UK. ON3 is a fully remote firm, so it sources and vets across the country rather than from a single city. London is the largest single market, but roles are filled nationally and remotely, including cross-border placements where a Spain-based engineer joins a UK company.
What kinds of engineers do you recruit in the UK?+
Software across the full stack (backend, full-stack, frontend, ML, data, platform, DevOps and engineering leadership), plus a fast-growing cybersecurity and deep tech practice covering areas such as chips and HPC. Deep tech is a particular UK strength.
Are ON3 a recruitment agency or do you employ the engineers?+
ON3 are headhunters and recruiters: you hire the engineer directly. If you need someone to act as employer of record, ON3 can arrange that through partners, but the standard model is permanent placement into your own company.

Tell us who you need to hire

Send us the role. You'll get a qualified shortlist in 24 to 48 hours, and for critical hires, a senior engineer who interviews every finalist.

Tell us who you need to hire →
Related

Sources & notes

ON3 figures (salary bands; 7%/20%, no deposit; 24 to 48h shortlist; <30-day median hire; 90.7% retention; 90-day replacement; 1.7M+ profile index; YC/Series-B and CGI references): supplied by ON3 Works.

UK time to hire (~4.9 weeks; tech 6 to 8 weeks): StandOut CV; NatWest Mentor (2026). Independent salary cross-check (London backend ~£79k median, ~£128k 90th percentile): Glassdoor; IT Jobs Watch (2026).

Note: the 24 to 48h shortlist is AI-screened-qualified, not yet engineer-interviewed; the engineer vet follows in Atelier. Salary figures are indicative and should be confirmed for a specific role and location.