Head of Growth in London

Join Proton and build a better internet where privacy is the default. Proton was founded in 2014 by scientists from CERN on a simple truth: privacy is a fundamental human right. Since then, we've built the world's largest encrypted email service (Proton Mail) and expanded into Proton VPN, Proton Drive, Proton Pass, and Proton Calendar - tools used by millions globally to protect their freedom, fight censorship, and keep their data safe. In some situations, Proton has literally helped save lives. We are profitable, independent (no VC control), and selectively hire from the top ~1% of applicants. Our 700+ team members across 50+ countries come from leading organizations and elite academic backgrounds. We move fast, keep hierarchy light, and prioritize impact over optics. If you want to do meaningful work with exceptionally high-caliber people, this is it.

Purpose of the role

We're looking for a Head of Growth to own product-led growth for Proton Mail & Calendar. The focus is on finding and building the mechanisms inside the product itself that drive activation, conversion, retention, and virality, while partnering closely with marketing to align product-led and marketing-led efforts into a single growth strategy. You'll work closely with product, engineering, and marketing to design, ship, and iterate on growth loops, owning the roadmap and the metrics that come with it.

What you will do

• Own the end-to-end user funnel, including signup, onboarding, activation, free-to-paid conversion, upgrade paths, and retention, and identify where friction or leverage exists at each stage.
• Design and ship in-product growth experiments (onboarding flows, activation nudges, paywalls, upsell moments, referral and invite mechanics) in close partnership with product managers and engineers.
• Partner closely with product marketing, influencer, social, and performance marketing teams to develop cross-functional growth strategies that connect top-of-funnel acquisition with in-product activation and retention.
• Partner with the other product teams on core Mail and Calendar features that maximise retention and LTV.
• Build and own a rigorous experimentation pipeline, including hypotheses, A/B tests, instrumentation, and clear read-outs that inform both the product and marketing roadmaps.
• Identify and build virality and network-effect loops (referrals, sharing, collaboration features) that drive organic growth, coordinating with marketing on how these loops are amplified externally.
• Define the core growth metrics for the business (activation rate, conversion rate, retention/churn, LTV, referral coefficient, etc.) and be directly accountable for moving them.
• Partner with data and analytics teams to build the instrumentation and dashboards needed to see the funnel clearly and act on it.
• Synthesize user research and behavioral data into product and marketing bets that improve the funnel, acting as the user's advocate inside planning across both functions.
• Directly influence the product roadmap, treating growth as a core input into what gets built next.

Job requirements

• Proven experience owning product-led growth at a SaaS or consumer tech product, having built or scaled onboarding, activation, conversion, or retention systems from inside the product.
• Experience working cross-functionally with marketing teams (product marketing, performance, social, influencer) to align product and marketing growth efforts.
• Fluency in experimentation: designing tests, understanding statistical validity, and knowing when a result is actionable versus noise.
• Strong technical and analytical fluency, comfortable in product analytics tooling, and able to speak credibly with engineers about implementation trade-offs.
• Experience building or scaling virality and referral mechanics, ideally in a product with network effects.
• Leadership by influence, with the ability to align product, engineering, marketing, and data stakeholders outside your reporting line around a shared growth vision.
• A strong bias toward shipping and testing, matching Proton's culture of hands-on builders.
• A cost-efficient, scrappy mindset, as Proton is bootstrapped and wins through smart execution rather than big budgets.
• Comfort with ambiguity and a willingness to make bold, high-conviction calls about where the growth potential lives in the product.

Why Proton:

• Work that Matters: millions of people trust Proton with their privacy. We answer only to our users — not advertisers, not investors with conflicting agendas, not governments. The work you do here is real, and the impact is measurable.
• A great Team: Our team is diverse, collaborative, and tight-knit with people coming from all walks of life, including many of the world’s top academic institutions and organizations, such as MIT, Harvard, Stanford, Caltech, Cambridge, and ETH.
• Technology: you'll get the right hardware and the right software you need to do your best work.
• Learning & Development: we invest in your growth because sharp people make us better. Proton is one of the fastest ways to accelerate your career because you'll be thrown into real challenges, with real ownership, from day one.
• Employee Benefits: your wellbeing isn't an afterthought. We offer strong health coverage, solid retirement options, generous leave, and wellness support so you can bring your best self to work every day.
• Stock Options: at Proton, we all have the opportunity to be owners of the company. From day one, you have a real stake in what we're building. When Proton wins, you win.
• In-Person Collaboration: Amazing things happen when passionate, smart, and purposeful people get together in the same room. With offices across Geneva, Zürich, Barcelona, London and more, you'll spend most of your time collaborating face-to-face with people who genuinely care about what they're building.
• Food: Lunch and snacks are on us every day in our offices so you can focus on the work and not on what's for lunch.
• Transport: getting to the office shouldn't cost you. We cover public transport, bike allowances, or parking, whichever works for you.
• Flexible Working: you own your schedule. Set hours that work for you and your team — because outcomes matter more than when the clock says you started.

Our Commitment to Diversity and Inclusion

At Proton, we believe diversity drives innovation and strengthens our mission to provide privacy as a default for all. We are committed to fostering an inclusive environment where all individuals, regardless of race, ethnicity, gender, age, sexual orientation, physical ability, or socio-economic background, feel valued and empowered. We strive to create equal opportunities, promote open dialogue, and support continuous learning to ensure every voice is heard and respected.

If you need any extra support or reasonable adjustments during the hiring process, please let your talent partner know.