Lead Growth Engineer, Fyxer AI
£140-250k
£140K – £250K Equity
AI executive assistant
Be an early applicant
AI executive assistant
21-100 employees
Be an early applicant
£140-250k
£140K – £250K Equity
21-100 employees
Company mission
Get back one hour every day. Begin your day with emails neatly organized, replies crafted to match your tone and crisp notes from every meeting.
Role
Who you are
- Thorough understanding of TypeScript and React
- Can function as a full-stack engineer (leaning heavily towards front-end development), working on both client and server-side code, answering data questions using SQL, and contributing to DevOps and CI/CD processes
- Core growth skills including data analysis, UX design, and product development, combined with a passion for marketing and conversion psychology to ideate and build high-impact experiments
- A sense of urgency and intensity in your work
- Broadly, we use a fairly typical serverless Typescript stack. It’s not a requirement to have worked with every tool in this stack, but the more the better:
- Typescript for all production code
- Firestore as our production database
- Firebase Auth as our auth system
- Backend deployed on Firebase Functions, and making use of PubSub and Cloud Storage
- React frontend, using ShadCN for components, TailwindCSS for styling, React Query for state management
- Posthog for frontend analytics (events, sessions)
- Growthbook for product experimentation (feature flags, experiments, bandits)
- BigQuery as our data warehouse, with Metabase for data visualization. Production data and Posthog events both stream into it so data is in one place
- Sentry and Google Cloud Logging for monitoring
- Github Actions for CI/CD
- Cursor/Claude Code/OpenCode setup for each engineer in the team
Desirable
- Worked at an early-stage tech company as an engineer (<100 people), or been a founder
- Keen interest in LLMs, workflow automation, and AI agents
- Previous experience as a growth engineer or as a software engineer in a growth team, or you’ve demonstrated through self-driven work any of the following: optimising customer journeys, building virality/seat expansion/referrals, or building revenue operations infrastructure
- Knowledge of the typical B2B SaaS growth/revops stack—experimentation, CRM, segmentation tools
- A deep understanding of product growth mechanics. You think in terms of growth/habitual loops and network effects rather than just funnels. You’re comfortable using multivariate testing and correlative analysis to shorten time-to-value and identify the early indicators of long-term retention
What the job involves
- Each of our Growth Engineers owns one of Fyxer AI’s growth loops - whether that be a viral loop within a product, or an onboarding, monetisation or referral journey
- They own both the strategy (we have no product managers and have no plans for that to change) and the execution of that strategy
- They choose when to bring in qualitative data (customer interviews, surveys etc) and quantitative, supported by our data engineering department
- We’re very intentional about adding new people
- We think a small team of exceptional people working hard at a problem they care about will always beat a larger, less focused team
- That does mean you’ll need to bring an intensity to this role that might not be asked at other companies
- But it also means you will be fast tracked into more senior roles and responsibilities far earlier
- In short, you'll be expected to come up with and entirely own implementing your experiment ideas to improve product-led growth at Fyxer AI
- Although you'll be working alongside other growth engineers, this role requires a lot of independence and self-management to come up with ideas and execute them
- You'll use data from Metabase, BigQuery, and PostHog to generate new ideas, analyse your experiments, and prioritise your backlog
Application process
- Submit your CV (no need for a cover letter)
- Initial call with someone from the Fyxer AI team to review your experience and motivation and a small 10 min paired programming challenge (30 mins)
- Experience interview with one of our growth engineers (30 mins)
- Practical interview (1hr):
- Wireframe an experiment and talk us through your thinking (30 mins)
- Live coding exercise (30 mins)
- Meet Richard, CEO (30 mins)
Salary benchmarks
Our take
Built with the intention of turning the burden of email drafting into a business's competitive edge, Fyxer AI delivers AI executive assistants that can organise inboxes, draft emails in the tone of voice of each user, and write "better-than-human" meeting notes. Plugging directly into Gmail, Outlook, Slack, Teams, Google Meet and Zoom, its service is simple to use without the need to grasp additional software.
Fyxer is especially useful for industries that spend large amounts of time composing emails. Think real estate, consultants and recruiters, all saving time through the pure-play AI software of Fyxer and its open-source AI models and retrieval augmented generation. The company claims that its customers send 53% of the email drafts generated on its platform.
As more and more professionals turn to AI to save them time in their everyday tasks, Fyxer AI's secure and streamlined service is sure to gain more attention. Things certainly look to be going well, as in 2024, the company raised $500K in just three weeks from existing customers and their networks. It also rocketed from $1m ARR to $22m in just 10 months in 2025 - a sure-fire sign of the value users see in its offering
Steph
Company Specialist at Welcome to the Jungle
Company
Funding (last 2 of 3 rounds)
Sep 2025
$30m
SERIES B
Mar 2025
$10m
SERIES A
Total funding: $40.5m
Company values
- What do we value? We're very intentional about adding new people. We believe a small team of exceptional people working hard at a problem they care about will always outperform a larger, more unfocused team. That means you'll need to bring an intensity to this role that might not be expected at other companies but it also means you'll be fast-tracked into roles with greater responsibilities far earlier.
Company HQ
Midtown Manhattan, New York
Leadership
Archie Hollingsworth
(Co-Founder & CRO)Founding Member of Pavilion. Co-founded FYXER, an Executive Assistant Agency, in 2016, and is now using that knowledge at Fyxer AI.
Matthew Ffrench
(Co-Founder & CTO)Previously co-founded and was CTO at Mercado. Was also Product Manager at Zopa.
Richard Hollingsworth
(Co-Founder & CEO)Founding Member of AI Circle. Co-founded FYXER with Archie, and was a Quant Trader at Bull Moose Derivatives.
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