---
title: 'Founding Engineer at Isidor'
canonical: 'https://feeny.ai/job/founding-engineer-isidor-london-aew6376z4bsk'
type: 'job'
last_seen: '2026-09-12'
---

# Founding Engineer at Isidor

- **Company:** Isidor
- **Location:** London, United Kingdom
- **Posted:** 2025-10-24
- **Last confirmed live:** 2026-09-12
- **Apply:** https://job-boards.greenhouse.io/isidor/jobs/4050484009

## Job description

## About Us

Isidor is building the foundation of reliable AI. We believe that the next leap in AI depends as much on understanding and measuring model behavior as it does on model size. To make AI trustworthy, we need systems that verify outputs, benchmark performance, and automate evaluation across billions of examples.

Isidor was founded by engineers and researchers who care deeply about precision, transparency, and scientific rigor. We are a small, fast-moving team working directly with frontier AI labs and enterprise to make evaluation as measurable and reproducible as training itself.

Founded in September 2025, Isidor raised an oversubscribed $3.6m pre-seed from leading funds including Gradient Ventures, futurepresent and Seedcamp, along with angels from Google DeepMind, Perplexity, Motive, Episode 1 and more.

## The Role

As a Founding Engineer, you’ll own the architecture that defines how AI reliability is measured, from scalable backend systems to forward deployed pipelines and client-facing APIs.

You will:

- Design and build the core infrastructure for data ingestion, evaluation, and benchmarking at scale
- Implement automated pipelines that measure model reliability, and evaluation metrics
- Lead DevOps and cloud automation
- Collaborate directly with AI research labs and enterprise clients
- Contribute to the company’s technical direction, culture, and engineering standards from first principles

## What We’re Looking For

- 1-5 years building and scaling backend systems, strong experience with front end
- Understanding of cloud infrastructure (AWS, GCP)
- Expertise in DevOps, CI/CD, and performance tuning
- Experience building end-to-end systems from scratch
- Proven collaboration record with small teams, wearing many hats

Bonus points if you have:

- Built large-scale ML evaluation or annotation platforms
- Designed metrics pipelines for AI workflows
- Experience in AI research teams or startups to design technical infrastructure
- A strong appetite for a fast paced environment requiring initiative and ownership

## Why Join Us

Your work will directly influence the development of the next generation of AI models, giving you the opportunity to make an outsized impact on frontier research and implementation in enterprise.

Our momentum: 0 → 7 figures in revenue in <1 month

Backed by: Gradient Ventures, futurepresent, Seedcamp, along with angels from Google DeepMind, Perplexity, Motive, Episode 1 and more

Details

Employment Type: Full time, in-office

Location: London (in-person), with potential for relocation to San Francisco in H1 2026 (with visa support)

Compensation: Competitive salary + equity

## Benefits

- Relocation package
- Housing bonus (if within 3 miles of the office)

Please reach out with any questions to founders@isidor.ai

## About Isidor

## Company Overview
- **One-liner**: Isidor develops secure, vertically-integrated pipelines that transform raw, unstructured enterprise data into reinforcement-learning-ready curricula for model training, evaluation, and alignment.
- **Entity Type**: Private (Pre-Seed; raised $3.6M)
- **Headquarters**: San Francisco, California, United States (with a London office)
- **Founded**: September 2025
- **Founders**: Andrew M. (CEO & Co-Founder), Antonios Valkanas (Co-Founder & CTO), François V. (Co-Founder)

## Core Business
- **Primary Industry**: Artificial Intelligence / Enterprise AI infrastructure
- **Target Customers**: B2B – frontier AI labs and large enterprises needing secure, custom model training and evaluation pipelines
- **Mission / Purpose**: “Building the foundation of reliable AI” – making AI trustworthy by verifying outputs, benchmarking performance, and automating evaluation at scale.

## Products & Services
- **Reasoning Trace Data**: Captures complex workflows and reverse-engineers them from the ground up for model training.
- **Foundation Model Post-Training**: Fine-tuning and alignment on proprietary enterprise data and internal practices.
- **Verifiers**: Post-processing systems for generative AI outputs, tailored to critical enterprise processes.
- **Evaluation**: State-of-the-art benchmarks for specialized industry verticals, paired with best-in-class agentic evaluations.
- **Data Pipelines & Infrastructure**: Custom data ingestion, cleaning, and processing pipelines designed for reinforcement learning and evaluation workflows.

## Market Standing
- **Valuation / Market Cap**: Not disclosed
- **Key Metric**: Total Funding – $3.6M pre-seed (oversubscribed). Revenue – reached 7 figures within the first month of operation, according to job postings.
- **Notable Investors / Partners**:
  - Lead investors: Gradient Ventures (Google’s AI fund), futurepresent, Seedcamp
  - Angels from Google DeepMind, Perplexity, Motive, Episode 1
- **Growth Signals**: Rapid revenue generation (0 → 7 figures in < 1 month); small team (approx. 4–5 employees as of early 2026) operating in both San Francisco and London; direct collaboration with top AI labs and enterprise clients.

## Competitive Advantages
- **Vertically-integrated, secure pipelines** that handle raw, unstructured data end-to-end – from capture to model training and evaluation.
- **Focus on reliability and measurement** – treats evaluation as a first-class, reproducible engineering discipline, not an afterthought.
- **Enterprise-grade privacy and compliance** built into the core infrastructure, appealing to regulated industries.
- **Direct access to frontier labs** and the ability to embed engineers with research teams.

## Strategic Focus
- **Current Priorities**: Scaling the engineering team (hiring Founding Engineers and Forward Deployed Engineers); deepening integrations with frontier AI labs; expanding enterprise adoption in sectors requiring high reliability.
- **Direction**: Shifting the AI reliability conversation from model size to verifiable behavior – making evaluation “as measurable and reproducible as training itself.”

## Why Work Here
- **Culture**: Tight-knit, fast-moving team of engineers and researchers who value precision, transparency, and scientific rigor. Emphasis on ownership and wearing many hats.
- **Work Policy**: Full-time, in-office in London (in-person), with potential relocation to San Francisco in H1 2026 (visa support provided).
- **Notable Perks**: Relocation package, housing bonus (if within 3 miles of the London office), competitive salary + equity.
- **Impact**: Direct influence on the development of next-generation AI models and frontier research; systems built here will be used by top AI labs globally.

## Sources
1. [isidor.ai](https://isidor.ai)
2. [linkedin.com](https://www.linkedin.com/company/isidorai)
3. [greenhouse.io - Founding Engineer](https://job-boards.greenhouse.io/isidor/jobs/4050484009)
4. [greenhouse.io - Forward Deployed Engineer](https://job-boards.greenhouse.io/isidor/jobs/4048584009)
5. [tracxn.com](https://tracxn.com/d/companies/isidor/__q4sE2KpzZy8wPYa4CaLlV-3Kn19uHl7GBvMOIIrYD_U) *(Note: Tracxn lists Isidor as “unfunded,” conflicting with official job postings; we rely on the more recent and primary sources from the company.)*

## Other roles at Isidor

- [Intern](https://feeny.ai/job/intern-isidor-london-tzxbygtet32h) — London, United Kingdom
- [Open Application](https://feeny.ai/job/open-application-isidor-london-k8wtz4cn98zq) — London, United Kingdom
- [Forward Deployed Engineer](https://feeny.ai/job/forward-deployed-engineer-isidor-london-3zrhbf7hpk38) — London, United Kingdom
- [Founding Engineer](https://feeny.ai/job/founding-engineer-almedia-berlin-y3yjr148grcs) — Berlin, Germany
- [Founding Engineer](https://feeny.ai/job/founding-engineer-tightrope-san-francisco-qvmc2rbwg528) — San Francisco, CA
- [Founding Engineer](https://feeny.ai/job/founding-engineer-workstream-lehi-4x9m4p0be2ac) — Lehi
- [Founding Engineer](https://feeny.ai/job/founding-engineer-fleetcraft-london-cp921q6ewjc1) — London, United Kingdom
- [Founding Engineer](https://feeny.ai/job/founding-engineer-super-set-hive-community-united-states-san-francisco-bay-area-19c3x2m254mt) — United States / San Francisco Bay Area
- [Founding Engineer](https://feeny.ai/job/founding-engineer-ara-so-san-francisco-0rdn6e45jmwg) — San Francisco, CA
- [Founding Engineer](https://feeny.ai/job/founding-engineer-terrarium-new-york-tz9670qs26v7) — New York, NY