Staff Software Engineer (£130k–£150k + Equity) at Alexa-founder’s neurosymbolic AI startup

Company: Jack & Jill
Apply for the Staff Software Engineer (£130k–£150k + Equity) at Alexa-founder's neurosymbolic AI startup
Location: London
Job Description:

Staff Software Engineer

Salary: £130k–£150k + Equity

Company

Neurosymbolic AI startup founded by the creator of Amazon Alexa’s core technology, building reliable and explainable generative AI for tier-1 financial institutions.

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.

Location: London, UK

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.

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.

The ideal candidate

  • 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.

#J-18808-Ljbffr…

Posted: June 2nd, 2026