Senior Growth Engineer

Senior Growth Engineer - CRO & Marketing Focus

Salary: Up to £140k/year DOE + equity

Location: Chancery Lane, London — Mon–Thu in office, Fri WFH

About Fyxer

Fyxer is an AI Email & Meeting Assistant that eliminates admin burden for professionals in client-facing roles — sales, consultants, and recruiters. We understand your inbox, draft replies in your own voice, and take crisp meeting notes.

We're a pure-play applied AI company — not a SaaS product with AI bolted on. We use fine-tuned open-source models, tool use, and retrieval-augmented generation. Users send 53% of the email drafts we generate.

Since launching in March 2024, we've grown from $0 to $30M+ ARR. We raised a $10M Series A and a $30M Series B in under 18 months. Our backers include Marc Benioff (Salesforce), Harry Stebbings (20VC), David Singleton (ex-CTO of Stripe), and Madrona.

The Role

We're hiring a Senior Growth Engineer with a dedicated CRO and marketing focus, sitting within our Growth Engineering team and taking meaningful ownership of the conversion journey from paid traffic through to revenue. You'll work closely with the Head of Growth Engineering to shape strategy while driving execution yourself.

Your primary domain is the marketing layer — ICP-targeted landing pages, programmatic SEO, lead magnet micro-apps, and every mechanism that turns a visitor into a paying customer. You will instrument, test, and optimise every step of this funnel with engineering rigour.

Growth Engineers own their area of the product end-to-end, with strong support from the team around them. No PMs — you drive your own execution.

What You'll Own

Conversion Rate Optimisation

• Drive our CRO programme across the user journey — from landing page through to paid activation and seat expansion

• Design, build, and run multivariate experiments to improve conversion rate and sign-up quality for long-term retention

• Contribute to the experimentation infrastructure: testing frameworks, statistical rigour, result interpretation, and rollout decisions

Marketing Engineering

• Build and optimise ICP-targeted landing pages that speak directly to the pains of sales professionals, consultants, and recruiters

• Own programmatic SEO infrastructure and lead magnet micro-apps as conversion channels

• Collaborate with Marketing to align product-side CRO with paid and organic acquisition funnels

Data & Insight

• Work with quantitative data (product analytics, revenue data) and qualitative data (customer interviews, session recordings) to identify the highest-leverage opportunities

• Identify sign-up quality signals that predict long-term retention and feed those learnings back into acquisition targeting

Growth Loop Strategy

• Contribute to Fyxer's broader growth loop strategy: virality mechanics, referrals, seat expansion, and upgrade flows

• Ship full-stack features end-to-end — this is a real engineering role, not tool configuration

What We're Looking For

Must-Haves

• Experience as a CRO, growth, or software engineer with a track record of improving conversion across sign-up, onboarding, or monetisation flows

• Detail-oriented with a strong eye for design and UX — comfortable with CSS/React animations and substantial front-end experiments

• Deep, intuitive understanding of consumer psychology: why certain words, layouts, and sequences drive action

• Comfortable designing and interpreting multivariate tests and correlative analyses; you know the difference between statistical significance and practical significance

• Proficient in our stack (or close to it): TypeScript, React, Next.js, TailwindCSS, ShadCN, React Query, serverless functions

• Knowledge of the B2B SaaS experimentation stack: feature flagging, CRM integrations, event tracking, segmentation tools

• Comfortable moving between quantitative rigour and qualitative instinct — you know when to run an interview and when to run a query

• AGI-pilled: you love AI, actively use it in your workflow, and want to automate as much as possible

• You bring intensity — genuine ownership from day one, not waiting to be told what to test next

Nice to Have

• Experience with session recording tools (Hotjar, FullStory, PostHog), funnel analytics platforms, and product event tracking pipelines

• Familiarity with LTV modelling, cohort analysis, and churn prediction

• Experience with AI-assisted development workflows (Cursor, Claude Code, or similar)

• Prior experience at a fast-growing B2B SaaS or AI startup

Why Fyxer?

We are intentional about our team. We believe a small, exceptional team working with extreme focus will always outperform a large, bloated organization.

• Autonomy: We hire people who want ownership and then we actually give it to them.

• Velocity: You will be fast-tracked into senior responsibilities far earlier than at a traditional company.

• Scale: We are on track to hit $100M in revenue by the end of 2026. This is a rare opportunity to join a high-growth rocket ship at the foundational stage.