CRO Specialist in London

We are looking for a CRO (Conversion Rate Optimisation) Specialist to support Proton’s Marketing team in improving conversion across our marketing websites and landing pages, spanning traffic from SEO, performance marketing, affiliates, and partnerships. You will help run a steady cadence of experiments and landing-page iterations that improve key funnels such as acquisition, sign-up, and upgrade, ensuring tests are well-scoped, properly measured, and clearly documented. You will collaborate closely with Design, Engineering, Product, and Analytics teams plus channel owners, to turn insights into high-quality tests and ship changes that measurably improve user outcomes.

What you’ll do:

• Be part of end-to-end experiment scoping and preparation by helping write and refine hypotheses, draft experiment briefs, align with the team on primary metrics and key guardrails, and translate requirements into the landing page/page-variant updates needed ahead of launch.
• Work in close alignment with the Data/Analytics team to review funnel performance, understand drop-offs and bottlenecks, and translate insights into prioritized test ideas and clear next actions.
• Coordinate with Product, Engineering, and Analytics to align on measurement needs (events, tracking plans, tagging assumptions, dashboards) so experiment readouts are reliable and consistent.
• Partner with Design, Content, and marketing channel owners to adapt landing page messaging and structure to match traffic intent and channel needs (Organic, Performance Marketing, Affiliates, and Influencers).
• Create, iterate on, and QA landing pages and experiment variants in the page/content publishing workflow, ensuring consistency across devices and key entry points.
• Document experiment outcomes, decisions, and learnings in a structured way so insights compound over time and enable faster iteration across future tests and teams.

Job Requirements:

• An experimentation mindset: you are curious, structured, and guided by a user-first mindset, focusing on measurable improvements across acquisition, sign-up, checkout, and upgrade funnels.
• 1 to 3 years of experience in conversion rate optimization and experimentation, with exposure to at least one of the following areas: growth, lifecycle, or performance marketing, and clear examples of measurable conversion impact.
• Ability to translate insights into clear hypotheses, define primary metrics and guardrails, and support A/B tests through launch, QA, and readout.
• Solid analytical foundations: comfortable reviewing funnel performance, spotting drop-offs, and turning results into prioritised next actions with Data/Analytics.
• Tracking and measurement literacy: able to align with Product and Engineering on events, tagging assumptions, and dashboards so results are reliable.
• Hands-on landing page optimisation: build, iterate, and QA pages and variants in a CMS/page builder, with strong attention to detail across devices.
• Strong cross-functional collaboration and documentation: coordinate with Design, Engineering, Product, and channel owners, and document learnings so iteration gets faster.

What We Offer:

• 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.
• Work with smart and dedicated people - 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.