Senior CRO Manager

• Must-Have Experience

  • CRO / Experimentation: 3+ years running A/B tests on a D2C subscription or consumer web product, with results you can attribute to your own work.

  • Product Analytics: Hands-on proficiency in Mixpanel or a close equivalent - building funnels, segmenting by device and geography, and reading cohort behaviour without analyst support.

  • Statistics: Working knowledge of significance, power, sample size, and common pitfalls such as peeking and sample ratio mismatch.

  • Experimentation Platforms: Experience with a feature-flag or A/B testing platform (GrowthBook, Statsig, or close equivalents).

  • Conversion Copy & UX: Ability to write and critique conversion copy and page layouts, grounded in behavioural psychology.

  • AI Tooling: Active daily use of AI tools (Claude or equivalent) to accelerate concept, analysis, and prototype work.

  • Compliance: Familiarity with consumer protection rules for subscription products and marketing claims is a bonus.

  Leadership Attributes

  • Holds a high bar for their own work and the team's - tests ship clean, documented, and correctly called

  • Constantly learns and adopts new tools and methods

  • Ambitious - driven to build large-scale products used by millions

  • Explains decisions clearly in writing - a hypothesis, a verdict, or a prioritisation call can be understood without a meeting

  • Communicates clearly and proactively in a remote, async environment

We are looking for a hands-on Senior CRO Manager to drive conversion growth for one of our core D2C subscription products. You will be fully responsible for a continuous pipeline of A/B tests - from hypothesis and prioritisation through launch, analysis, and documented verdicts - working with the CRO Lead to grow the number of statistically validated winners across the funnel.

This is a high-impact role suited for someone who treats experimentation as a system, not a list of ideas. Tests without a clear hypothesis, verdicts called before the evidence supports them, and results that are not documented are not acceptable. You are expected to know the funnel numbers, segment before you conclude, and work closely with the data team, product, and engineering. The bar is high and so is the upside - performance here is directly and significantly rewarded, and strong operators take on bigger scope fast.

• Experiment Pipeline: Own the A/B test backlog from hypothesis to launch. Prioritise ideas by expected impact, confidence, and effort, and keep the pipeline full so live traffic is always being used to learn.

• Funnel Analysis: Analyse the funnel in Mixpanel to find drop-offs, friction points, and segment-specific opportunities across devices and locales, and turn them into testable hypotheses.

• Test Analysis & Verdicts: Read results with statistical rigour, separate winners from directional trends and noise, and prepare clear verdicts for sign-off with the data team.

• Test Specification & QA: Write test specs and variant briefs that developers can build without follow-up questions, and check every variant before and after launch.

• Conversion Copy & Layouts: Produce conversion-oriented copy and layout variants that stay within compliance constraints on product claims.

• Documentation & Reporting: Keep every test documented in Notion with hypothesis, setup, result, and learning, and contribute to regular experimentation reporting for leadership.

• Mentoring: Support a junior CRO specialist on test design, analysis, and documentation standards.

Ruby Labs operates within the CET (Central European Time) zone. Applicants from any country are welcome to apply for the position as long as they are located within approximately ± 4 hours of CET. This ensures optimal collaboration and communication during working hours.

At Ruby Labs, we move fast, aim high, and expect the same from our team. We're not here to play small-we're here to build, grow, and win. That means we look for people who are ambitious, driven, and ready to give their best every single day.

This is a place for individuals who thrive under pressure, embrace challenges, and see opportunity in every obstacle. If you're hungry to achieve, motivated by impact, and want to grow at the speed of your own ambition, Ruby Labs offers the platform to make it happen.

Here, effort is matched with reward. We recognize those who go all in and deliver results, and we create space for people who want more-more responsibility, more growth, and more success.