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Senior AI Product Engineer

Remote, Barcelona·Full-time·Added yesterday (last checked 6 Nov)

Oyster HR

15 open roles

Our summary

Work mode
Remote (Barcelona)
Contract
Full-time
Experience
Senior level

Visa options

  • The ad doesn’t mention sponsorship

    Not a refusal, but not a yes. Worth asking in your first message.

  • May fit the digital nomad visa

    A remote job for a company outside Spain: you apply yourself, no sponsor needed. It asks for about €2,849 a month in remote income.

More jobs that may fit the digital nomad visa

Skills

Requirements

What we're looking for

  • Senior-level engineering judgment and a track record of independently leading complex production work from design through operation and improvement.

  • Hands-on experience shipping LLM-powered product capabilities to production, with clear personal responsibility for implementation and delivery decisions.

  • Real depth in at least some of the following: retrieval/RAG and indexing, evaluation datasets and experiments, LLM-as-judge, or agents and tool calling.

  • The ability to tell model, retrieval, tooling and application failures apart, and to validate improvements with evidence.

  • Strong fundamentals in coding, debugging, testing, API integration and system design, plus willingness to work in Ruby/Rails and React.

  • Sound judgment about sensitive data, access control, model limitations and operational risk.

  • Clear communication of trade-offs, effective async collaboration with product and engineering partners, and practical mentoring.

Nice to have

  • Production experience with Ruby on Rails, especially integrating AI capabilities into an established backend.

  • Full-stack delivery of conversational or assistant experiences.

  • Slack or in-app assistant integrations with clear user and permission context.

  • Operating retrieval pipelines, agent tools, evaluation infrastructure, or model routing and cost controls at production scale.

  • Helping multiple teams adopt reusable AI patterns while balancing shared foundations against local needs.

Pay & benefits

What you'll get

  • Paid time off: Enjoy 40 days off per year (including holidays and vacation), or more if required by your country.

  • Mental health support: Access Plumm, our mental well-being service.

  • Wellbeing allowance: Each month, receive a wellbeing allowance in your ThanksBen wallet to spend on a wide range of options.

  • Flexible parental leave: All new parents are eligible for at least three months' paid leave, with job protection for up to 12 months or as required locally.

  • WFH stipend: Receive a stipend for your laptop and home office equipment to get you set up quickly.

The role

The best jobs have always clustered in a handful of the world's wealthiest cities. But talent is everywhere. Oyster set out to close that gap - building a global employment platform that lets companies hire, pay, and care for brilliant people anywhere.

We're proof that a high-performing culture doesn't need an office. Distributed across 60+ countries since 2020, we've built something the industry keeps noticing:

Two of those rankings measured our business impact from the outside. One measured how our own people feel about working here. They landed in the same place ~ because at Oyster, culture and performance aren't separate conversations. They're the same one.

And we're just getting started. If you want to do the best work of your career alongside people who care as much as you do, we'd love for you to apply.

Oyster AI is our assistant for customers and team members, and we want it to be genuinely useful: accurate, fast, reliable and safe with the data it touches. In this role you'll own complex improvements to it end to end, from defining the problem and designing the solution through evaluation, rollout and learning from production.

Your work will span agent capabilities and tools, knowledge retrieval, answer quality and infrastructure, with real trade-offs between model quality, latency, reliability and cost. This is a hands-on product engineering role, not a research-only or prompt-only position. You'll also help other product teams build AI features well by sharing patterns, pairing with them and improving the reusable foundations they rely on.

Our backend is Ruby on Rails and our frontend is React. Strong AI engineers from other stacks are very welcome, and Rails experience is a bonus, not a prerequisite.

What you'll do

  • End-to-end AI improvements. Connect user needs to architecture, implementation, evaluation and safe rollout for complex Oyster AI work.

  • Reliable agents and tools. Design clear tool contracts, robust error handling and bounded execution, with appropriate human control over consequential actions.

  • Better knowledge access. Choose retrieval, embedding, indexing and freshness strategies that improve answers while respecting data access boundaries throughout retrieval and generation.

  • Evaluation you can trust. Build evaluation loops with representative datasets, experiments, regression checks and, where useful, automated judges calibrated against human judgment.

  • Root-cause fixes in production. Diagnose failures across prompts, retrieval, tools, models and infrastructure, fix the underlying cause and verify the fix with evidence.

  • Explicit trade-offs. Choose models and system designs deliberately, and document decisions and rollout criteria.

  • AI capability across teams. Support other product teams through technical guidance, code review, pairing and mentoring, so they can deliver AI features independently.

How you'll work

  • Thoughtful remote culture. You'll join a fully remote, async-friendly team that values documentation and clear decision-making.

  • Work from anywhere: Oyster has no borders or HQ. As long as work is timely, your team is supported, and you're authorized to work where you live, you can work from anywhere.

About Oyster HR

Oyster HR is a global employment platform that enables companies to hire, pay, and manage employees and contractors in over 180 countries without setting up local entities. The company provides a comprehensive suite of HR tools, including global payroll, benefits, and compliance management, positioning itself as a leader in the HR tech space. Oyster HR was founded in 2019 and has grown rapidly, serving a diverse range of clients from startups to large enterprises.

Industry
HR Tech
Founded
2019
Employees
500–1,000
Headquarters
San Francisco, USA

Good to know if you are moving

  • Oyster HR is a remote-first company, offering flexibility to work from anywhere, which is ideal for international professionals.
  • The company has a strong focus on diversity and inclusion, with a global team representing many nationalities.
  • Oyster HR provides opportunities to work on cutting-edge HR technology that impacts global employment.
  • The company offers competitive benefits and supports professional development, making it attractive for career growth.
  • While the global HQ is in San Francisco, Oyster HR operates with a distributed workforce, so Spain-based roles are likely remote-friendly.

In their own words

About the company & team

  • Real AI in production. You'll ship to real users, and success is measured by evaluations and user outcomes, not plausible-looking demos.

  • Ownership of hard problems. You'll work across agents, retrieval, evaluation and infrastructure, where engineering judgment matters at every layer.

  • Multiplier impact. Your patterns and mentoring will shape how AI is built across multiple product teams.

  • Stack-agnostic hiring. We hire for AI engineering depth, and you'll have room to grow into Rails and React.

Our values guide the work we do, the decisions we make, and the culture that makes Oyster what it is. We make it happen-progress is our default setting. We drive change, we build and give trust, and we move as one united team.

Our mission is to create a more equal world of work: helping companies everywhere hire, pay, and care for talent anywhere. Everything we do ladders up to our mission. We embrace asynchronous, collaborative work and share how we operate in the Oyster Public HQ so other global teams can learn from us.

Additional information

With diverse locations, cultures, and needs, we created How YOU Work; a program supporting your whole human experience at Oyster:

We embrace diverse perspectives and intentionally build our product and company with an inclusive, global mindset. We encourage you to apply, even if you don't meet every criterion, and are committed to a trust-based, thriving environment.

Oyster is committed to ensuring equal opportunity of employment for qualified persons with disabilities and actively fosters an inclusive work environment. If you require reasonable accommodations throughout the recruiting process, please email jobs@oysterhr.com with the subject line: Interview Accommodations.

Our available positions are on our careers page. Our team will only contact you from an @oysterhr.com email, and we will never ask for money as part of an interview process or job offer. If you receive a suspicious email about Oyster jobs or are directed to a site other than www.oysterhr.com/careers, please report it via our Compliance and Ethics Helpline.

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