At a Glance
- Tasks: Architect and build an AI-powered concierge system for a luxury membership platform.
- Company: BLACKLINE, an exclusive private membership platform in London.
- Benefits: Equity-based co-founder role with potential for significant impact.
- Other info: Early-stage startup focused on creating a seamless, high-end user experience.
- Why this job: Join us to redefine personal care experiences using cutting-edge AI technology.
- Qualifications: Strong experience in AI systems, voice tech, and backend engineering.
The predicted salary is between 80000 - 120000 € per year.
BLACKLINE is an exclusive private membership platform designed to provide an exceptional experience in aesthetics, wellness, fitness, and personal care across London. We pride ourselves on a meticulously curated network of top-tier operators to meet members' high standards. With a focus on personalized attention, BLACKLINE offers a seamless and bespoke experience. Membership is granted selectively, catering to individuals who value excellence and exclusivity.
Overview
BLACKLINE is a private, invite-only membership across London focused on health, beauty, and personal care. We are building a concierge layer powered by AI — designed to handle booking, coordination, and member preferences across messaging and voice, with the standard and discretion expected of a private members’ network. This is not a typical startup role. We are building infrastructure for experience, not a product for scale.
What You’ll Build
- Architect and ship the BLACKLINE Concierge Agent, operating across:
- WhatsApp (Primary Interface)
- Natural conversation handling (LLM-driven)
- Booking coordination with providers
- Memory of member preferences
- Context-aware responses (time, location, history)
- Voice (Phone Concierge)
- Real-time conversational agent
- Natural, human-like voice (e.g. ElevenLabs or equivalent)
- Call handling (inbound + outbound)
- Seamless escalation to human when required
- Backend Intelligence Layer
- User profiles + preference memory
- Provider availability + scheduling logic
- Workflow orchestration (requests → bookings → confirmations)
- CRM integration
- Design and build the end-to-end AI concierge system
- Select and integrate LLMs, voice models, and orchestration frameworks
- Build WhatsApp automation (e.g. via Twilio, Meta APIs, or equivalent)
- Implement real-time voice pipeline (speech-to-text → reasoning → text-to-speech)
- Ensure low latency and high reliability
- Maintain strict data privacy and security standards
- Define architecture that scales without degrading experience
- AI / LLM Systems
- Prompt engineering + agent design
- Tool use / function calling
- Memory systems (vector DBs, session memory)
- Multi-step workflow orchestration
- Voice Systems
- Real-time speech pipelines (STT / TTS)
- Latency optimisation for conversational flow
- Experience with providers like ElevenLabs or similar
- Messaging Infrastructure
- WhatsApp API integrations
- Event-driven systems
- Webhooks and async processing
- Backend Engineering
- Node.js / Python (preferred)
- API design
- Database design (relational + vector)
- Cloud infrastructure (AWS / GCP)
- You ship fast — not just design systems
- You understand user experience in conversation, not just code
- You can balance automation vs human touch
- You care about detail, tone, and discretion
- a chatbot
- a support tool
- a generic AI assistant
- Experience building AI agents in production
- Experience with booking / scheduling systems
- Familiarity with CRM tools (HubSpot, custom pipelines)
- Background in high-end consumer or service experiences
- Early-stage / pre-scale
- Building MVP → live concierge → refined system
- Equity-based co-founder role
- London-based preferred (not mandatory)
- trust
- consistency
- experience
Core Responsibilities
Technical Requirements
You should have strong hands-on experience in:
What We Care About (More Than Stack)
This is not:
It must feel like: a private concierge that already knows the member.
Nice to Have
Stage & Commitment
What Success Looks Like
A member can message or call BLACKLINE, make a request in natural language, and have it handled seamlessly end-to-end. No friction. No repetition. No drop in standard.
Why This Matters
Most AI products optimise for efficiency. We’re optimising for:
If you get this right, you’re not building a feature — you’re building the operating system of the brand.
Technical Co-Founder / CTO in London employer: BlackLine
At BLACKLINE, we offer a unique opportunity to be part of an exclusive private membership platform that prioritises excellence in aesthetics, wellness, and personal care across London. As a Technical Co-Founder / CTO, you will thrive in a dynamic work culture that values innovation and creativity, with ample opportunities for professional growth as you architect a bespoke AI concierge system. Join us in crafting a seamless experience for our discerning members while enjoying the benefits of equity participation and the chance to shape the future of luxury service delivery.
StudySmarter Expert Advice🤫
We think this is how you could land Technical Co-Founder / CTO in London
✨Tip Number 1
Network like a pro! Get out there and connect with people in the industry. Attend events, meetups, or even online webinars related to AI and tech. You never know who might be looking for a Technical Co-Founder or CTO!
✨Tip Number 2
Show off your skills! Create a portfolio that highlights your past projects, especially those involving AI and voice systems. This will give potential partners a taste of what you can bring to BLACKLINE.
✨Tip Number 3
Don’t just apply; engage! When you find a role that excites you, reach out directly through our website. A personal touch can make all the difference and show your genuine interest in the position.
✨Tip Number 4
Prepare for the interview by understanding BLACKLINE’s vision. Think about how your experience aligns with their focus on user experience and discretion. Tailor your responses to reflect their values and goals.
We think you need these skills to ace Technical Co-Founder / CTO in London
Some tips for your application 🫡
Show Your Passion:When you're writing your application, let your enthusiasm for the role shine through! We want to see that you’re genuinely excited about building something unique and exceptional at BLACKLINE.
Tailor Your Application:Make sure to customise your application to highlight your relevant experience and skills. We’re looking for someone who understands the nuances of AI and voice systems, so don’t hold back on showcasing your expertise!
Be Clear and Concise:Keep your application straightforward and to the point. We appreciate clarity, so make sure your ideas are easy to follow. Remember, we’re building a seamless experience, and that starts with your written communication!
Apply Through Our Website:Don’t forget to submit your application through our website! It’s the best way for us to keep track of your application and ensure it gets the attention it deserves. We can’t wait to hear from you!
How to prepare for a job interview at BlackLine
✨Know Your Tech Inside Out
Make sure you’re well-versed in AI and LLM systems, especially prompt engineering and memory systems. Brush up on your experience with real-time speech pipelines and messaging infrastructure, as these will be crucial for the role.
✨Showcase Your User Experience Mindset
This isn’t just about coding; it’s about creating a seamless user experience. Be prepared to discuss how you balance automation with the human touch, and share examples of how you’ve designed systems with user experience in mind.
✨Demonstrate Your Problem-Solving Skills
Think of scenarios where you had to troubleshoot or optimise a system under pressure. Be ready to explain your thought process and how you ensure low latency and high reliability in your solutions.
✨Emphasise Attention to Detail
Since BLACKLINE values discretion and a high standard of service, highlight your experience in maintaining data privacy and security. Discuss how you ensure that every interaction feels personal and tailored to the user.
