Senior Full Stack Engineer (d/f/m) SaaS Funnel London

The Formula; London; On-site; GBP 65,000 - 95,000; Full time

Job summary

A leading SaaS ScaleUp is seeking a seasoned full stack developer to join their team in London. In this influential role, you will enhance user activation through innovative system design and development, directly impacting product growth. The ideal candidate is experienced in React and has a robust understanding of analytics and user engagement strategies.

Qualifications

• Minimum of 7 years in full stack web development.
• Expert in React and SaaS activation.
• Experience with A/B testing and event tracking is essential.

Responsibilities

• Increase signups and enhance user onboarding experiences.
• Implement user-facing systems and backend services to support analytics.
• Collaborate cross-functionally to identify and resolve user drop-off issues.

Skills

Full stack web development

React

API development

Event tracking

Analytical skills

A/B testing

Communication

Job description

Your Benefits:

• Join one of the most driven and innovative SaaSScaleups.
  
• As one of the first hires to the team, you shape the workflows of a highly innovative ScaleUp from day one.
• Work for a globally established market leader with a presence in Barcelona,Spain and colleagues around the globe.
• Work from the headquarter in Barcelona, or from one of the offices in Madrid, Valencia, Berlin, London; or from home within EU.
• You will have built a first classsoftware system integrating andusing tools like React, Amplitude, Segment, BigQuery, PostHog, A/B testing tools, statistical analytics tools, event tracking, activation dashboards, North Star Metrics, growth loops, time-to-value.

Your Responsibilities:

• You are responsible for increasing signups and trial users, while ensuring new users quickly reach their time-to-value.
• You architect and build user-facing systems such as onboarding flows, API explorers, data previews, and sandbox environments.
• You implement backend services, activation logic, and telemetry pipelines to support usage analytics and product insights.
• You implement end-to-end features across the activation funnel such as onboarding UIs, walkthrough guides, wizards, checklists, in-app messages, and dashboards.
• You build self-serve capabilities (API explorers, data previews, sandbox flows) that increase integration rates.
• You partner with Product, Marketing, Sales, and Support to identify blockers and opportunities across the funnel.
• You analyze where users drop off and make improvements.
• You actively shape the future of the companies success.

Your Profile:

• Minimum of 7 years of professional experience in full stack web development.
  
• React expert.
• Designed and implemented systems supporting user activation in a B2B SaaS product stack.
• Expert in defining key activation metrics.
• Expert knowhow with implementing event tracking and activation dashboards.
• Experience with runningA/B tests and iterative experiments to improve signup, activation, and trial conversion.
• Experience in ensuring smoothdeployment and observability of new features.
• Being familiar with several tools for scalable product insights and customer data infrastructure.
• Comfortable with being measured by impact metrics, not just coding.
• Sophisticated sense for growing products and prioritizing engineering efforts based on business impact.
• Excellent verbal communication skills in English, with experience collaborating cross-functionally with product, marketing, sales, and customer support teams.
• Excellent written communication skills, demonstrated through a clear, concise, and tailored CV no longer than two pages,that highlights your relevant experience and shows why you’re a strong match for this specific role, including your Linkedin and GitHub profile.

Interested? Please apply via our homepagewith your current CV.

If you have any questions, feel free to reach out via email ([e-mail]) or WhatsApp [phone]).

We celebrate diversity.
That’s why we explicitly welcome all applications - regardless of gender, gender identity or expression, sexual orientation, age, ethnic or social background, nationality, religion or belief, physical or mental abilities, family status, appearance, or any other characteristic that must not be a factor under applicable law.

We firmly believe that diverse perspectives, experiences, and life journeys enrich teams and lead to better decision-making.