Technical Co-Founder (Full-Stack Developer)

Salary Unpaid

Equity To be negotiated

Role Description

This is a technical co-founder opportunity at Calibre Social — a Copenhagen-based hybrid role, part-time to start with a clear path to full-time as the company grows. Calibre is a social platform that helps people build real friendships around shared passions and turns those connections into in-person experiences with local businesses.

The Full Stack Engineer (Technical Co-Founder) will own the design and development of Calibre’s backend from the ground up and contribute to the React Native mobile frontend. Responsibilities include architecting the data model and API layer, implementing authentication and core app logic, collaborating directly with the founder on product decisions, writing clean and testable code, and supporting deployment and monitoring in production. Product design and UI are covered by the founding team (Figma/Adobe XD), so the focus is on architecture and engineering, not visual design. Compensation is equity-based (substantial founding stake, open to negotiation), with a cash component planned as part of the upcoming pre-seed raise.

Qualifications

- Strong proficiency in full-stack development, with experience building and shipping modern mobile or web applications.

- Demonstrated back-end skills: server-side development, API design, relational databases (PostgreSQL preferred; we’re building on Supabase), and auth flows.

- Experience with React Native and/or React; comfort with JavaScript and the Expo ecosystem is a strong plus.

- Strong knowledge of modern web technologies and frameworks (e.g., JavaScript/TypeScript, React or similar, Node.js or equivalent server-side stack).

- Familiarity with version control (Git), testing (e.g., Jest), and modern deployment workflows (e.g., EAS Build, CI/CD).

- Understanding of app security, performance optimization, and cloud-based infrastructure.

- Comfort with early-stage ambiguity — architecting fresh rather than executing a spec, and helping shape technical direction.

- Ability to work in a hybrid setup in Copenhagen and communicate clearly in English.

- Bachelor’s in Computer Science or equivalent practical experience; startup experience and interest in social/community-focused technology are a plus.

Loneliness is one of the biggest under-addressed public health issues (SDG3) of our generation, and I think there’s a genuinely different way to build a social platform that treats it seriously. We’ve done the work to prove it: validated business case, an MVP-stage prototype, and a roadmap that’s grounded rather than hype-driven (MVP → Nordic growth → a Web3 layer, sequenced deliberately, not because it’s trendy). What’s missing is a technical co-founder to build it with — not for it.

For more information or questions please contact us at w.adamisaac@gmail.com or phone number 21555515

Perks and benefits

This job comes with several perks and benefits

Central office

Equity package

Skill development

Social gatherings

Work life balance

Working at
Calibre Social

See company profile

WHAT_ Calibre is a social platform that connects people through shared passions and turns those connections into real, in-person experiences. We reduce the friction of meeting new people and make it easier to build meaningful platonic relationships — whether that means deepening existing friendships or discovering new IRL experiences and activities. We partner with local experience-economy businesses to host the meetups our matches lead to. TEAM_ We're a small, committed team based in Copenhagen. Ather Nawaz and Adam Isaac are building Calibre full-time, with backgrounds spanning Computer Science and Data Science, and a shared curiosity for ethically applied psychology in digital products. We're actively looking for a technical co-founder (full-stack) to join us as we take the product from prototype to launch. WHY_ The SDG target we're focused on is loneliness — a factor in life expectancy second only to smoking. It's a pressing issue for everyone, but especially for young people, who are facing rising rates of anxiety, depression and eating disorders. Research (Holt-Lunstad et al., 2010; Holt-Lunstad et al., 2017) shows that lacking social connection carries health risks comparable to — and in many cases exceeding — smoking up to 15 cigarettes a day, obesity, physical inactivity, and air pollution. Everyone should have access to fewer experiences of loneliness and more highly personal, memorable social experiences. Calibre fosters meaningful platonic friendships and real-life memories, making IRL social connection more accessible. HOW_ We're building Calibre so that IRL activities are as accessible as possible — deliberately not following the "doomscrolling" business model common in social networking. We're currently developing our MVP with a clear mission and a critical technical practice (CTP) mindset, working closely with small experience-economy businesses in Copenhagen to design the ideal platform for connection-driven meetups. For our SME partners, Calibre offers a more effective way to reach and retain customers than the e-commerce-optimized tools currently on the market — built specifically around the real, personal, immaterial value that IRL businesses provide. Copyright © 2026, Calibre Social (https://calibre.social/mission)