Why hiring a software engineer in the UK takes 4 to 12 weeks, and where the weeks go
Time to hire is a sum of small waits, and only some of them can be shortened. A week-by-week breakdown of a UK engineering hire, with the notice period nobody plans for.
Every survey of UK time to hire lands in the same band: four to twelve weeks from opening the role to an accepted offer, with senior engineering roles at the long end. Averages hide what matters, which is that the time is a chain of separate waits, each with its own cause. Some of them you can shorten. Some of them you cannot, and the most expensive one comes after the offer.
This is the chain for one mid-to-senior engineering hire in the UK, week by week, with what compresses and what does not.
Weeks 0 to 1: the brief
The role exists in someone's head before it exists on paper. Writing it down, agreeing the salary band, and getting it signed off takes a few days in a small company and two weeks in a large one.
This week is worth taking. A brief that names the stack, the seniority and the first thing the engineer will build shortens everything after it, because it lets candidates self-select and it gives whoever is sourcing something to match against. A brief that says "strong generalist, good culture fit" does the opposite.
Compressible: yes, down to a day, if the decision-maker is in the room.
Weeks 1 to 3: sourcing and outreach
Now the search. For an engineering role in the UK, job boards bring applicants but rarely the ones you want; the people you want are employed and not looking. So most of this phase is finding them and writing to them.
Done by hand, it is 100 to 300 profiles reviewed and 50 to 150 messages sent, at a few minutes each for anything better than a template. Engineers reply to templates at single-digit rates and to specific, well-informed messages at several times that, so the personalisation is where the time goes.
Then you wait. People check messages on their own schedule, and a reply within a week is a good outcome. Chasing helps, once.
Compressible: partly. The reviewing and writing parallelise well, which is why an agent gets this phase down from two weeks to a couple of days: HireBrain scores every profile against the brief and writes each message around the candidate's own work, and it does both in the background. The waiting for replies does not compress. People still take a week to answer.
Weeks 2 to 5: screening
Of the people who reply and look right, ten to twenty get a first conversation. This is the phase that quietly eats calendars, because every screen is a thirty-minute slot that both sides have to find, and the hiring manager usually has a job to do in between.
It is also the phase where a shortcut costs the most. Skip it and the interview loop fills with people who were never going to pass; do it badly and the good ones drop out because a first call felt like a form.
Compressible: yes, and this is where an agent makes the biggest difference. A calibrated technical screen that the candidate takes when they choose, marked consistently, means the hiring manager sees eight vetted people instead of twenty raw replies. The week of calendar tetris becomes an afternoon of reading results.
Weeks 4 to 8: interviews
Two to three rounds is standard for an engineering hire: a technical deep dive, a conversation with the team, and something with a founder or a director. Each round needs a slot that suits three or four people, and a week between rounds is normal once everyone's diary is involved.
Compressible: only by design. Fewer rounds, rounds on the same day, decisions on the same day. An agent cannot do this phase for you and should not try; the interviews are where the humans on both sides decide.
Weeks 6 to 9: offer
The offer takes a day to write and a week to land. References, a counter from the current employer, a second conversation about the salary band. A candidate who has been in a good process says yes quickly; one who has been in a slow one is often talking to someone else by now.
Compressible: yes, mostly by having the band agreed in week zero.
After the offer: the notice period
Here is the wait nobody puts in the plan. In the UK, the employee's notice period is written into the contract, and for engineers one month is standard, three months is common at senior level, and some contracts run longer. Accepted offer in week eight means a start date in week twelve at best and week twenty at worst.
There is nothing to compress. Buy-outs are rare and expensive, and gardening leave is the employer's call, not the candidate's. The only lever is to start earlier, which brings the whole chain back to the brief.
Where the weeks go, side by side
| Phase | Typical | With the legwork automated | Who can shorten it |
|---|---|---|---|
| Brief and sign-off | 1 to 2 weeks | 1 to 2 weeks | You |
| Sourcing and outreach | 2 to 3 weeks | a few days plus reply time | The agent, for the work |
| Screening | 2 to 3 weeks | under a week | The agent, for the screen |
| Interviews | 2 to 4 weeks | 2 to 4 weeks | You, by design |
| Offer | 1 to 2 weeks | 1 to 2 weeks | You, in week zero |
| Notice period | 1 to 3 months | 1 to 3 months | Nobody |
Read across and the pattern is clear. The phases an agent can take over are the ones made of repetitive work: reading profiles, writing messages, marking screens. The phases it cannot are the ones made of human decisions and contractual waits. Automating the first group takes three to five weeks off a typical hire; it moves the offer forward, and the notice period starts that much sooner.
What it means for planning
If you need an engineer in post by a date, count backwards: three months of notice, two months of process, and a brief that took a fortnight to agree. That is the six-month lead time that surprises most first-time hiring managers, and the reason the role that "we should probably open soon" is already late.
The cost side of the same hire, agency against in-house against agent, is in what it really costs to hire a software engineer in the UK. The tooling side, for companies that hire rarely, is in what LinkedIn Recruiter costs at two hires a year.