Principal Engineer (£100,000 + 2% Equity) at Rivulo.ai

This is a job that Jill, our AI Recruiter, is recruiting for on behalf of one of our customers.

She will pick the best candidates from Jack's network

The next step is to speak to Jack.

Job Title: Principal Engineer

Salary: £100,000 + 2% Equity

Company Description: Rivulo.ai - VC-backed AI automation startup

Job Description:
As the first technical hire, you will own the architectural evolution of an agentic workflow platform. Transitioning the codebase from the technical co-founder, you'll build robust systems that convert real-world behaviors into reliable AI automations. You will bridge the gap between complex LLM orchestration and seamless user experiences for non-technical teams.

Location: London, UK

Why this role is remarkable:

• Take total technical ownership as the first engineering hire, working directly with experienced founders who have multiple successful exits.

• Build at the cutting edge of AI, moving beyond simple wrappers to create complex, multi-model orchestration and autonomous browser automation systems.

• Experience a high-trust, radical transparency culture with self-management, full financial visibility, and the autonomy to make major architectural decisions without red tape.

What you will do:

• Evolve the platform architecture from v1 MVP to a scalable, production-grade system capable of handling thousands of concurrent AI workflows.

• Design and implement sophisticated LLM integrations, focusing on prompt engineering, token management, and real-time streaming reliability across OpenAI, Anthropic, and Google APIs.

• Collaborate directly with customers to understand friction points, translating messy real-world operational needs into elegant, automated agent-led systems.

The ideal candidate:

• Expert full-stack engineer with deep TypeScript/JavaScript proficiency and professional experience (or a strong willingness to master) PHP/Laravel 12.

• Proven track record in AI Engineering, including hands-on experience with LLM context window optimization, rate limiting, and building resilient retry logic for real-time interfaces.

• Entrepreneurial builder who thrives in autonomous environments, possesses a ""founder mindset,"" and is comfortable jumping into product or support tasks to drive company growth.

Who are Jack & Jill?
Ok, I'll go first. I'm Jack, an AI that gets to know you on a quick call, learning what you're great at and what you want from your career. Then I help you land your dream job by finding unmissable opportunities as they come up, supporting you with applications, interview prep, and moral support.
And I'm Jill, an AI Recruiter who talks to companies to understand who they're looking to hire. Then I recruit from Jack's network, making an introduction when I spot an excellent candidate.

Next steps
Step 1. Visit our website.
Step 2. Click 'Talk to Jack'.
Step 3. Talk to Jack so he can understand your experience and ambitions.
Step 4. Jack will make sure Jill (the AI agent working for the company) considers you for this role.
Step 5. If Jill thinks you're a great fit and her client wants to meet you, they will make the introduction.
Step 6. If not, Jack will find you excellent alternatives. All for free.

We never post fake jobs
This isn't a trick. This is an open role that Jill is currently recruiting for from Jack's network.
Sometimes Jill's clients ask her to anonymize their jobs when she advertises them, which means she can't share all the details in the job description.
We appreciate this can make them look a bit suspect, but there isn't much we can do about it.
Give Jack a spin! You could land this role. If not, most people find him incredibly helpful with their job search, and we're giving his services away for free.