Startups looking for a cofounder in Finland: how to join a founding team, not become employee number three

You do not want to start a company from a blank page. You want to join someone who already has the idea, the first customers or the working prototype, and build it with them as an owner. In Finland that person exists, and they are usually harder to find than a job, because nobody posts "cofounder wanted" on a job board and means it.

This guide is for the engineer, designer, operator or salesperson who wants to join a founding team as a cofounder. It covers where founders in Finland actually look, what you are asking for when you say "cofounder" rather than "first hire", how to read a founder's own ask, and how to write a profile that a founder reads and answers. It is the mirror of the guide for founders looking for a cofounder in Finland; read that one too, because it tells you what the person on the other side has been told to look for.

Who is looking for a cofounder in Finland right now

Trusted Cofounder is a free, public directory of people in Finland who are looking for someone to build with. Founders list themselves with what they are building and what they need; people who want to join list themselves with what they bring. There are 79 founders listed today on it, most of them in Oulu and Helsinki: 41 founders in Oulu listed today and 12 founders in Helsinki listed today, with smaller groups in Tampere, Espoo and elsewhere.

The founders split roughly three ways by stage. Some have an idea and nothing else, and want the person who turns it into a product or a first sale. Some have a minimum viable product a handful of people use, and need the skill they lack themselves, most often commercial if they are technical and technical if they are not. A smaller group has launched, has revenue, and wants a late cofounder to own a whole function. The filters do not sort by stage, but almost every founder says which they are in the first two lines, and the founders list is sorted by who was most recently active, so the first page is the people who will read your message this week.

For you, the action is not to browse but to be findable. Founders browse the cofounder side of the same directory, and a profile that says what you bring and what you want to build is how the right founder finds you. It takes about a minute and does not expire.

Cofounder, early employee or advisor: what are you actually asking for?

"I want to join a startup" covers three very different arrangements, and founders in Finland will assume the one you did not mean unless you say it.

An early employee gets a salary, an employment contract, and sometimes options under an option plan, which in Finland have their own tax rules. Less risk, less upside, and no seat at the table when the big decisions are made.

An advisor gives a few hours a month for a small slice of equity. The most widely used template, the Founder Institute's FAST agreement, puts advisor equity between 0.1% and 1% depending on the company's stage and how much time the advisor gives, vesting monthly over two years. If what you actually want is to help without committing your working life, say "advisor" and you will get a clearer answer from every founder you write to.

A cofounder is neither. You take founding shares, usually a double-digit percentage, in a company that may not pay you anything for a year or more. You get a real say, sometimes a board seat, and you carry the same risk as the person who started it. In a Finnish limited company (osakeyhtiö, Oy) this is straightforward on paper: since 1 July 2019 an Oy can be registered with zero share capital, so founding shares cost little to issue, and the split between founders is whatever you agree in the shareholders' agreement. Two things follow that first-time joiners often miss.

The first is vesting. Finnish startup shareholders' agreements almost always make founder shares earned over time: the Helsinki Region Chamber of Commerce describes the standard arrangement, shares that vest over a period such as four years from the start of work, with the company and the other shareholders given the right to buy back unvested shares if someone leaves, at a price that depends on whether the departure was a "good leaver" or a "bad leaver" case. A founder who offers you 20% with no vesting is either inexperienced or planning to renegotiate later. A founder who offers 20% vesting over four years with a one-year cliff is offering you the normal thing. Our guide to equity splits in Finland walks through the numbers, and the guide to the osakassopimus covers the agreement itself.

The second is pension insurance. In a leading position with more than 30% of the company alone, or more than 50% together with family members, you must take out YEL insurance as a self-employed person, as the Finnish Centre for Pensions explains. That is a monthly cost from your own pocket while the company pays you nothing: not a reason to refuse a large stake, but a number to know before you sign.

If any of that is new, start with what a cofounder actually is, then come back.

How do Finnish founders actually pick a cofounder?

Not from a post that says "experienced developer available for the right opportunity, DM me". Founders receive a steady trickle of those on LinkedIn and in Telegram groups and answer almost none, for a reason unrelated to your skills: the message asks the founder to imagine where you would fit, and the founder already has more work than time.

What founders actually respond to:

• Specificity about what you want to build. "I want to join a B2B SaaS company at the point where it has its first five customers and needs someone to own the product" is a sentence a founder can say yes or no to in three seconds. "Open to interesting opportunities" is not.
• Evidence you have finished things. A shipped product, a team you ran, a sales number you hit, a design that is live somewhere. Not a list of technologies. Founders scan for the verb "shipped" and its cousins.
• A reason it is them. The message that gets answered names something about the founder's own idea, city or stage. It reads as written once.
• Commitment stated in hours. "Evenings and weekends until we have revenue, then full time" is an honest position a founder can plan around. "Fully committed" with a full-time job in the next line is not.
• Where you are. Founding teams in Finland still mostly start in person. A joiner in Oulu writing to a founder in Oulu gets a coffee; a joiner with no city set gets a question, or no reply.

Most founders also look you up. A profile with a real name, a photo and a link to something you made turns a curious founder into a reply; an anonymous role label with three skill chips does not, and the directory ranks the empty profiles below the filled ones for the same reason.

Where are the startups looking for cofounders?

Five places, in roughly the order that produces a founding team rather than a coffee.

The public directory. The founders on Trusted Cofounder have written down, in their own words, what they are building and whom they need. You filter to founders, read the descriptions, and write to the two or three whose ask fits what you bring. Because the whole thing is public and free, the people on it are there because they want to be found, which is the entire point. It works best when you are also listed, so a founder who browses the other way finds you first.

Pre-incubators and accelerators. These take teams, but they also take individuals who want to join a team, and the cohort is where a lot of Finnish founding teams complete themselves. In Oulu, Startup Express is a 14-week pre-incubator run by BusinessOulu that is open to anyone who has a business idea or wants to join an existing team, two to three times a year. In the Helsinki region, Kiuas runs a four-week validation sprint and a longer growth residency out of Otaniemi, free and without taking equity, and accepts solo builders as well as teams. In Tampere, Tribe Tampere operates the Platform6 community and runs matchmaking nights specifically for early builders. If you are a joiner, the trick is to show up to the community events these programmes host rather than only to their application forms; the teams that need you are the ones already in a cohort and short one person.

University venture tracks. Aalto's student-run Aaltoes has been the pipeline for a large share of Helsinki founding teams since 2009, and the universities in Oulu and Tampere run their own entrepreneurship programmes and events, several of which we cover in the guides on Aalto, Oulu and Tampere. You do not have to be a student; the public events are the door.

Slush and the week around it. Slush is in Helsinki on 18 and 19 November 2026, and its side events are where many "we should build something" conversations start and almost none finish. Our guide on the cofounder search after Slush covers the six weeks after, where teams actually form.

Your own last three jobs. The least glamorous and, for most Finnish founding teams, the most common: the cofounder is someone you already worked with. If a former colleague keeps talking about an idea, that is a live lead. The founders listed publicly are mostly the ones whose own network came up empty; our guide on having an idea but no cofounder is written for them and tells you what they have been advised to look for.

How do you read a founder's ask?

Every founder's description tells you more than it says. Four things to decode before you write.

Stage. "I have an idea for" means you would be building from zero, with the most equity on the table and the most risk. "We have an MVP and a few pilot users" means the shape exists and the founder now knows what they cannot do themselves; this is where a joining cofounder is most valuable and most welcome. "We launched and have revenue" means you would be a late cofounder, with a smaller stake, a clearer role and a real company around you. None of these is better. They are different jobs. Decide which one you actually want before you filter.

Time commitment. A founder who is full time on the company and asks for a full-time cofounder is asking you to quit your job for equity in something that may not pay for a year. A founder who is part time and says so is asking for something you can test alongside your job. A founder who says "full time" but whose profile suggests otherwise is a conversation to have early, not late.

"Open to either." Some founders say they are open to building their own idea or joining someone else's. These are often the best fits for a joiner with half an idea of their own, because the first conversation is two people comparing notes rather than an interview.

Red flags. A founder who will not tell you the idea before you sign something. A founder who has had three cofounders leave. A founder who offers a title instead of equity, or equity with no vesting, or "we will sort out the split later". A founder whose description is entirely about the market size and not at all about what has been done. Our list of cofounder red flags is written for both sides, and the guide on validating an idea before committing to a cofounder is worth sending to a founder who has not done it yet; how they react tells you most of what you need to know.

What does a joiner's profile look like when it works?

Your profile is doing one job: letting a founder who is right for you recognise that in ten seconds. Three parts, in this order.

What I bring. Not a skills list. Two or three things you have actually done, with the outcome. Founders do not need to know you know TypeScript; they need to know you took a product from nothing to paying users, or ran a sales pipeline that closed, or designed something people use every day.

What I want to build. The stage, the kind of company, the problem space if you have one, the city, and the commitment you can make. This is the part that filters. A narrow, honest sentence here gets you fewer messages and better ones.

What I will not do. The part almost nobody writes and every founder appreciates. Not full time before revenue. Not a consumer app. Not an equal split for an idea with no validation. It saves you and the founder a wasted coffee.

Here is one, written for this guide rather than taken from any profile, at about the length the directory's description field is built for:

I have spent eight years as a backend engineer and the last three as the first technical hire at two Helsinki B2B startups, one of which I took from a prototype to its first paying customers and a team of five. I am looking to join an early-stage company as its technical cofounder at the point where there are a few pilot users and someone needs to own the product and the engineering roadmap. Ideally B2B, ideally in health, logistics or industrial software, in the Helsinki region or hybrid. I can do evenings and weekends for the first months and go full time once there is a first paying contract. I am not looking to be a contractor for equity, I am not interested in consumer apps, and I will not join without a shareholders' agreement with vesting on both sides.

About 120 words: level, evidence, stage, domain, city, commitment and terms, and the wrong founder can move on without writing to you. Notice what it lacks: adjectives about yourself, a list of frameworks, the word "passionate".

Fill in the rest too: a real photo and name make a founder click, a specialization and three or four skills put you in the right filters, and a link to something you built makes the description believable.

What first message actually gets answered?

On this directory, writing to someone is an interest with an opening message; they see it on their Interests screen, and if they accept, the conversation opens with your message already in it. You can see on your Sent tab whether they have seen it yet, and an interest nobody has answered after 30 days can be withdrawn. That is the whole mechanism, and it means your first message is read before the other person has decided anything about you. Write it accordingly.

The message that gets answered is short, specific to them, and ends with a question they can answer in one line. Roughly:

Hi, I read your description about the logistics MVP with three pilot warehouses. I spent three years building exactly this kind of integration layer at my last company and I am looking to join something at your stage as a technical cofounder, part time until first revenue. Would a 30-minute call next week make sense, and is the current bottleneck the product or the sales?

It names their thing, states what you are and what you want, states your commitment, and asks two concrete questions. It does not attach a CV, it does not ask them to explain the idea from scratch, and it does not say you are excited.

Write to people who are active. Every profile shows when the person was last active and the founders list is sorted by it; three well-aimed messages to people active this week beat fifteen to the whole list.

Frequently asked questions

Do I need my own idea to be a cofounder? No. Most of the founders on the directory have the idea and need the person. What you need is to be clear about what you bring and what stage you want to join at. If you have half an idea of your own, say so; it makes the first conversation better.

Can I do this alongside a job? Usually, at the start. Many Finnish founding teams begin with one person full time and one part time, and the shareholders' agreement can make the part-time cofounder's vesting or role change when they go full time. Say your real availability in your profile and in your first message. Founders plan around honesty and resent surprises.

How much equity is normal for a joining cofounder? It depends on when you join and what exists. Joining at the idea stage, an equal or near-equal split is common. Joining after an MVP with users, something smaller but still a founder-sized stake, vesting over about four years with a cliff, is the usual shape. Anything you are offered should come with a shareholders' agreement; the equity split guide has worked examples and the reasons behind them.

Do I need to be in Helsinki? No. Oulu has the largest group of founders on this directory, and Tampere and Espoo have active ones. What matters more than the city is whether you and the founder can meet, at least at the start; set your city on your profile so the founders near you can find you.

Do I need to speak Finnish? Not to find a cofounder. The directory is in English, most descriptions on it are in English, and Finnish founding teams work in English far more often than not. It helps later with some customers and some public funding paperwork, and a Finnish cofounder covers that.