As a Staff Software Engineer, you will lead the transition from bespoke enterprise deployments to a scalable public API platform. You will bridge the gap between LLMs and symbolic computing, architecting foundational systems that enable AI to reason with deterministic accuracy. This is a high-impact IC role shaping the technical trajectory of a mission-critical AI platform.
Back to all jobs
Find a job with Jack
Staff Software Engineer at UnlikelyAI
Join the neurosymbolic AI startup founded by the creator of the technology behind Amazon Alexa. We are seeking a Staff Software Engineer in London to lead the architecture of our new public API platform. Our technology combines the reasoning power of symbolic computing with the flexibility of LLMs to catch errors in financial reporting that human reviewers miss. With a £130k–£150k base salary and meaningful equity, you will solve intellectually demanding problems at the intersection of classical AI and modern generative models. If you are a Python expert ready to shape a foundational AI platform for tier-1 global banks, this is your next career-defining role.
About this role
Role overview
About the company
Software
UnlikelyAI is a London-based technology company pioneering neurosymbolic AI, which integrates the strengths of machine learning with symbolic computing to deliver reliable, explainable, and trustworthy artificial intelligence systems. Their platform emphasizes controllable, auditable, and hallucination-free AI solutions for decision-making, especially tailored for enterprises in highly regulated industries where transparency and trust are critical. Founded by William Tunstall-Pedoe, their technology bridges probabilistic machine learning and deterministic symbolic systems—aiming to eliminate common AI risks such as hallucinations, bias, and black-box decision-making. Unlikely AI's Universal Language (UL) underpins their solutions, enabling robust applications for large language models and generative AI. The company focuses on building AI products capable of previously impossible tasks, with a strong commitment to responsible development and real-world usability.
What you'll do
What you will do
- Architect and implement the foundational public API platform, including critical decisions on authentication, versioning, and multi-tenant scalability.
- Design and optimize document ingestion pipelines that process complex regulatory data across multiple jurisdictions and formats like PDF and Word.
- Lead cross-cutting technical initiatives within a Python monorepo to improve engineering velocity, reliability, and observability across the entire organization.
Who you are
Who this is a fit for
- Possesses deep expertise in Python with a focus on writing well-typed, production-grade code and managing complex project structures at scale.
- Demonstrates a proven track record of making foundational architectural decisions and designing complex algorithms for high-availability systems.
- Has significant experience with AWS infrastructure (S3, EKS, Terraform) and a passion for establishing rigorous engineering standards and mentor cultures.
Why this role
Why this role is remarkable
- Work at the bleeding edge of AI by combining symbolic reasoning (decision trees and knowledge graphs) with LLMs to solve the hallucination problem for enterprise clients.
- Join a high-pedigree team founded by William Tunstall-Pedoe, whose previous company Evi was acquired by Amazon to become the foundational technology for Alexa.
- Play a pivotal role in a company with proven product-market fit at tier-1 banks and accountancy firms as they scale their technology into a global developer platform.
Jack & Jill
How Jack & Jill work together
I get to know what you’re great at, then find roles you’d never find yourself.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.
I recruit from Jack’s network and make the intro when I spot a great match.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.
Meet Jack
Jack gets to know what you're great at and what you want next, then searches 15 million jobs daily and helps you discover roles at companies like this.
How does this work?
Jack’s an AI agent for job searching and career coaching. He works for you.
Jill is the AI recruiter working for the company. She recruits from Jack’s network.
If it’s a match and the company wants to meet you, they’ll make the intro. In the meantime, if you’d like, Jack will send you excellent alternatives.