Do you need a co-founder? Pairing science with business skills

1. Core idea and who it's for#

Most scientist-founders ask "do I need a business co-founder?" too early and in the wrong words. The useful question is narrower: which jobs must a founder do in the next 18–24 months, which of them can't I do or learn quickly enough, and can someone other than a co-founder do them? A co-founder is the most expensive way to fill a gap. They take a large share of the equity and a permanent seat in every decision, and a break-up is painful (3.12). Use one when the gap is central, lasts for years, and needs founder-level commitment.

In deeptech, the gap is rarely "business" in general. It is usually one or more of these jobs:

• selling to the first customers or partners, which in regulated or industrial markets means long, technical, trust-based sales;
• raising money , and telling a story that investors can underwrite;
• building the company: hiring, finance, legal, operations;
• turning research into product: engineering, manufacturing and quality, which is a technical gap that founders often miss.

The practitioner consensus is that a deeptech team must cover all of these. One VC put it as: someone who can sell to customers, turn technology into a product, and build a business (Global Venturing). Whether that someone must be a co-founder depends on the stage, the market and you.

There are four realistic answers:

1. A commercial co-founder now: the gap is central and you're raising soon.
2. A scientist-CEO with a strong adviser network, adding a commercial founder or executive later: this works when the early work is mostly technical and the sales are expert-to-expert.
3. A technical co-founder (product, engineering, manufacturing): this works when you are the commercial lead or can grow into it.
4. An experienced CEO brought in at or after the seed round (3.04).

Who this is for: researcher-founders deciding whether to look for a co-founder, and what kind. For where to find one, see 3.02. For how to test fit, see 3.03.

2. Evidence: teams, solo founders and what investors look for#

Investors still prefer teams, but solo founding is rising. Carta data covered in 1.18 shows:

• the share of new US startups with a solo founder rose from about 24% in 2019 to 36% in H1 2025;
• solo-founded companies raise a disproportionately small share of priced-round money;
• more than a quarter of two-founder teams lose a co-founder by year four.

The lesson isn't "always get a co-founder". It's that a co-founder adds capacity and credibility, and also adds a real risk of break-up that has to be managed (3.06, 3.07, 3.12).

Deeptech investors look at the whole team. Investors interviewed by Global Venturing said:

• In 50–70% of the spinouts one venture builder works on, the academic wants to stay on the founding team.
• Academics need to recognise their gaps and hire around them, rather than try to do everything.
• Teams must be able to sell, turn technology into a product, and build a business (Global Venturing).

One specialist deeptech angel fund looks for multidisciplinary teams because, it says, they create a talent moat from day one (Maddyness, on Empirical Ventures).

How the business role is usually covered. An ESCP study of deeptech founding teams found that business responsibility was usually concentrated in one person. That person was either the only non-scientist, recruited specifically to bring the business view, or a scientist who gradually took on commercial leadership. Several startups deliberately avoided recruiting a "pure" business co-founder early. Hybrid, technically trained founders reduced friction, but risked personal overload (ESCP Research Brief).

Weak commercial co-founders hurt. One analysis of the Global Deep Tech Report 2025 notes that a commercial co-founder with only 2–3 years of business experience lowers a deeptech startup's odds. It also notes that in deeptech, founder-led sales often depend on the scientist's own credibility, which no commercial hire can replace (Edunomix).

The implication: an inexperienced "business person" is not automatically better than a scientist who learns, plus good advisers.

3. Method: the gap test#

Step 1. List the founder jobs for the next 24 months. Use the milestones you'll raise on. A typical deeptech list:

• a working prototype or pilot data;
• 2–3 customer or partner pilots;
• a pre-seed or seed raise;
• the first 3–5 hires;
• licence and IP work;
• regulatory or certification planning;
• manufacturing or scale-up partners.
• Step 2. Score yourself, and any existing co-founder, on each job. Use a 1–5 scale:
• 1 — never done it, and no interest;
• 3 — done it once, or could learn it in 6 months with help;
• 5 — done it well, repeatedly.

Ask someone who has seen you work to score you too (1.01).

Step 3. Classify each gap. For every job scored 1–2:

Step 4. Choose the structure.

• Two or more critical, lasting gaps in sales, fundraising or company building: look for a commercial co-founder (3.02, 3.03), and give them real equity (3.05).
• One gap, or mostly a technical-product gap: look for a technical co-founder, or make an early senior hire (6.02).
• Gaps that are real but not urgent: stay scientist-CEO , build an advisory network (1.12), take a fellowship or accelerator place that teaches the missing skills (1.10, 1.14), and plan to bring in a commercial executive or CEO later (3.04, 3.17).

Step 5. Set a review date. Revisit the decision at each milestone. A solo scientist-founder with no commercial lead by the time of a seed raise is a common investor objection. Have an answer ready: who covers sales and fundraising, with what evidence.

Worked example (illustrative)#

A materials scientist is spinning out a low-carbon cement additive. Her scores:

Two gaps are central and lasting: industrial sales and scale-up .

• Sales into cement producers depends on relationships and on long trials that need a credible industry voice, and her credibility as the inventor helps but isn't enough.
• She decides to look for a co-founder from the cement or construction-materials industry with commercial or plant-operations experience, and to give them substantial equity, about 35–40%.
• She covers fundraising herself, with a pitch coach and an accelerator.
• For hiring and finance, she uses a fractional CFO and incubator support.

While she searches, she runs a trial project with two candidates (3.03): each leads one pilot negotiation over 8 weeks.

4. India / US / UK differences#

India#

• Investor expectations. Indian deeptech investors and government programmes often back scientist-led teams from IITs, IISc and CSIR, provided there is a credible commercial lead or a plan to get one. Incubators (1.11) often match founders with mentors or entrepreneurs-in-residence who can become co-founders.
• Faculty founders usually stay at their institute (2.12). That makes a full-time CEO, whether a student, a postdoc or an outside co-founder, more important.
• The talent pool. Experienced commercial co-founders in deeptech sectors are scarce. Engineers-turned-operators from industry, such as auto, pharma, chemicals or semiconductors, are often the best source.

US#

• The deepest pool of potential co-founders: EIR programmes, venture studios, Activate, Cyclotron Road-style fellowships, and university venture builders. Investors expect a full-time CEO, and often a technical lead who has left academia. A professor-only team rarely raises institutional money (2.12).
• Solo founders are increasingly funded in software, but less so in hardware, bio and industrial deeptech.

UK#

• Spinout culture often assumes an external CEO, brought in by the TTO, a venture builder or the first investor (3.04). The Independent Review encouraged founderfriendly terms, which makes it more attractive for experienced commercial cofounders to join early.
• Venture builders and talent programmes actively match scientists with commercial founders, such as Deeptech Labs, Conception X, Entrepreneur First and university entrepreneurship programmes (3.02).
• Founder teams are not diverse enough. One RAEng Enterprise Hub analysis notes that 83% of UK deeptech spinout founding teams are all-male (RAEng Enterprise Hub). Searching beyond your immediate network widens the pool.

5. Scripts, mistakes, related playbooks and sources#

Scripts#

When an investor asks "who's your business person?":

"For the next 12 months the work is technical: pilot data and two industrial trials. I'm leading those, and I'm already in the room with customers. We're actively looking for a co-founder with plant and commercial experience in cement. Here's the profile and our shortlist. Until then, these two advisers cover fundraising and pricing."

Approaching a potential commercial co-founder:

"I'm not offering a job, I'm looking for a partner. The technology works at lab scale. The hard part ahead is getting it into plants, and that's where you're stronger than me. Would you spend eight weeks working on one pilot negotiation with me, to see how we work together before we talk about equity?"

Saying no to a mismatched co-founder:

"You'd be a great adviser, and I'd love you on our board of advisers. Where we need a co-founder is someone who has sold into plants. That isn't your background, and I don't want to put you in a role that doesn't fit."

Common mistakes#

1. Recruiting a generic "business co-founder" with little experience in your market.
2. Giving away co-founder equity for a short-term gap that an adviser or contractor could fill.
3. Missing the technical-product gap, such as engineering, manufacturing or quality, because you assume the gap must be "business".
4. Waiting until the seed raise to address an obvious gap, so investors fill it for you on their terms.
5. Assuming you must be CEO, or that you can't be.
6. No trial period before committing (3.03).

Related playbooks#

• 1.01 Should I start a company?
• 1.09 Founder-market fit
• 1.18 Solo founder or team?
• 2.12 Professor as co-founder
• 3.02 Where to find co-founders
• 3.03 Co-founder dating
• 3.04 Bringing in a business CEO
• 3.05 Splitting founder equity

Sources#

• Entrepreneur vs academic: who makes the best leader of a spinout?, Global Venturing
• How deeptech founding teams bridge science and business, ESCP Research Brief
• Brilliant science, empty chair, Edunomix
• A profile of Empirical Ventures, Maddyness
• UK deep tech spinout moment: what to fix, RAEng Enterprise Hub
• Carta data on solo founders and co-founder departures: see the sources in 1.18

The worked example is illustrative. Last checked November 2026.