AI Research Engineer (Model Training)

About StackOne

StackOne is the universal integration layer for modern SaaS products. We''ve raised $24m in 2 years, and we''re backed by top tier investors like Google Ventures and Workday Ventures.Our unified API platform lets vendors ship hundreds of native, white label integrations in days, not months, by abstracting away dozens of disparate third party APIs into a single, normalized interface. On top of those APIs, we provide AI Agent Actions so customers can build agentic workflows without wrangling OpenAPI specs.StackOne sits behind the scenes as an embedded iPaaS: SOC 2 compliant, multi-tenant, and invisible to end users powering integrations for future-of-work SaaS categories such as HR, Compliance, and AI Agents.Our customers are established B2B SaaS companies that:Sell to mid market and enterprise buyersAre building AI Agents in the near futureNeed deep, native integrations to win competitive deals and power their productValue time to integration over building connectors in houseWe typically close OEM and embedded licensing deals, multi-year (1 to 3 year) contracts, five to seven figure TCV, with a strong land and expand model. Key buyer personas are the CPO and CTO.About the role

We''re building a world where users of any SaaS can integrate with the tool of their choice in one click thanks to StackOne. We''re convinced AI is pivotal to making this a reality by transforming how SaaS talks to each other and this is what you will help achieve.We are looking for an

AI Research Engineer

with deep expertise in

large-scale model fine-tuning, dataset curation, and training infrastructure . Unlike our AI Engineer role, which focuses on applying and productionizing existing LLMs and agent frameworks, this role is focused on

pushing model performance through fine-tuning, synthetic data pipelines, and large-scale experimentation .You will own, design and run experiments on cutting-edge architectures, manage distributed training clusters, and help curate and generate high-quality datasets. This role sits closer to the research/ML infra side than product engineering, but with a strong mandate for applied, production-ready results.In this role, you will work with wider AI team of StackOne (comprising of other researchers and engineers) and report directly to the CTO.Responsibilities

Own the full lifecycle of

model fine-tuning projects

(objectives, dataset prep, training, eval, deployment handoff).Design and manage

synthetic data generation

workflows to augment real-world datasets.Build and maintain

large-scale training infrastructure

(multi-GPU/TPU clusters, orchestration, optimization).Develop tools for

dataset curation, labeling, filtering, and augmentation .Conduct

benchmarking, and evaluations

to measure fine-tuning impact.Collaborate with the rest of the engineering team to integrate fine-tuned models into production stacks.Stay ahead of research in parameter-efficient fine-tuning, synthetic data, and LLM training.What we\''re looking for

Background in

deep learning , with emphasis on

LLMs .Experience running

large-scale distributed training jobsUnderstanding of

synthetic data techniques

and dataset pipeline design.Proficiency in evaluating LLMs with

quantitative metrics and human evals .Desire to work in a fast-paced startup, taking ownership of projects e2e and bias towards shipping.(Preferred) Contributions to open-source ML libraries or published research in applied ML/LLM fine-tuning.Our Stack

ou will have a lot of freedom and agency to chose and work with the technologies you love.

Our tech stack includes:Infra and monitoring:

AWS (ECS, RDS, Elasticache, Lambda etc.), Cloudflare, Tinybird, Modal, Dagster, Langsmith, Datadog, Sentry, Incident.ioLanguages and Frameworks : Typescript (Node.js), Python, NestJS, React, Svelte,Other day-to-day Tools:

Postman, Notion, Slack, Jira, Github and moreBenefits

25 days holiday + 1 additional day holiday per year of tenureParticipation in the company\''s employee share options planPrivate health insurance (including dental and optical)Health, fitness and gift card discounts£1,000 for your home office set up + £500/year top-upPaid lunch in the officeAnnual team offsite to sunny spots (last ones were in Spain and Portugal )Join one of Europe\''s fastest-growing startupsWork with a veteran team of ex-employees of Google, Microsoft, Oracle, Coinbase, JP Morgan and moreCycle2Work and Electric Cars schemeHybrid work set up - typically 2d in the officeReady to help us change the game for SaaS integrations? Get in touch and let\''s chat!We believe diversity drives innovation. We encourage individuals from all backgrounds to apply. As an equal-opportunity employer, we celebrate diversity and are committed to creating an inclusive environment for all ..... full job details .....