Guide // Technical co-founder
You probably don't need a technical co-founder. You need three things one would do.
The search fails for a structural reason: engineers good enough to be your co-founder are good enough to found their own thing, and most of them already have an idea they like better than yours. You are not competing with other startups for them. You are competing with their own.
What you are actually trying to buy
Almost nobody wants a co-founder for the companionship. Strip the title away and there are three jobs underneath, and a co-founder is only one way to get them, and the most expensive one.
- Someone to make the architecture callsNot to write the code. To decide what gets built, in what order, on what, so that the decisions do not have to be unmade later.
- Someone to check the workEspecially now, when a model will confidently produce something that runs, passes a demo, and is quietly wrong in a way you cannot see.
- Someone accountable when it does not workThis is the one people actually mean when they say co-founder. It is also the one you can buy without giving away a quarter of the company.
Five ways to get them, and what each costs
| Option | Cost | What nobody tells you |
|---|---|---|
| Technical co-founder | 20% to 50% equity | Permanent, dilutive, and extremely painful to unwind if it goes wrong. On a £5m exit, 25% is £1.25m. That is the real price, and it is paid at the moment you can least afford it. |
| Agency build | £30,000 to £150,000 | They build it and leave. You own a codebase nobody on your team can maintain, and the second version costs as much as the first. |
| Senior full-time hire | £70,000 to £110,000 plus equity | Right answer eventually. Three months to hire, and hard to assess if you cannot evaluate engineers yourself. |
| Fractional CTO | £1,600 to £8,000/mo | Senior judgment without equity or a salary. Still a monthly commitment, and you need enough work to justify it. |
| Learn it, with senior help | One fixed fee | Slowest to start and cheapest by an order of magnitude. Only works if you will genuinely do the building. |
The equity line is the one worth sitting with. A quarter of the company feels cheap when the company is worth nothing, which is exactly when you agree to it. It is the most expensive thing on this table by a wide margin, and the only one you cannot renegotiate later.
When you genuinely do need one
Three cases where none of the alternatives work, and where holding out for the right person is the correct call.
- The technology is the product, not the delivery mechanism. A new database, a model, a codec.
- You need someone in the room at 2am for years, and no fee arrangement survives that.
- Investors in your specific sector will not fund a solo non-technical founder, and you have checked rather than assumed.
If none of those describe you, the honest read is that you have a hiring problem you have framed as a co-founder problem, and it is solvable for a great deal less than a quarter of your company.
What I would do instead
Build it yourself, with someone senior making the calls you cannot make yet and checking the work as it lands. That was impractical advice five years ago. It is reasonable now, because the writing of code is no longer the bottleneck. Knowing which of the things the model just suggested is right, and which will still be standing in a year, is.
That is what The Founding Engineer is: 8 weeks, 5 founders, one senior engineer. Architecture decided with you, your code reviewed every week, in production by week 8 or a full refund. £2,500, once, and no equity.
It only works if you will do the building. If what you actually want is for someone else to build it, say so on the call and I will point you at the sprint or at a good agency instead.
Keep the equity
8 weeks, 5 seats, £2,500 for the founding cohort. In production by week 8 or a full refund, and not a percentage point of your company.