Backend Mid Developer

Frekuent; Barcelona; Hybrid; EUR 60,000 - 90,000; Full time

Benefits offered by this job

Hybrid work model (office 3 days)

Meal vouchers

Private health insurance

English classes

Professional development

22–23 days of paid time off

Team events & teambuilding

Job summary

Frekuent is seeking a backend engineer to own features end-to-end, from architecture to release, within a senior product engineering team. You will co-create AI-powered workflows and integrations, collaborating with Product and Data teams to ship high-quality code rapidly.

You will participate in architectural discussions, review code, and help design scalable, reliable systems for a modern payment and loyalty platform.

Qualifications

• 3+ years building backend systems in production.
• Experience in product companies, not just agencies.
• Contributed to a product's 0→1 journey: conception, build, ship, measure impact.
• Comfortable in fast, data-driven agile teams.
• Azure experience is a strong plus.
• Fluent in Spanish and English.
• A degree in CS/CE or equivalent; we care about shipped work.
• Experience integrating LLM APIs, RAG, or vector DBs.
• Prompt engineering or AI agent frameworks experience.
• Opinions on MLOps and able to defend them.
• Experience with payments/fintech infra is a plus.

Responsibilities

• Own features end-to-end: architecture, implementation, release, and metrics.
• Use AI-assisted development as a default workflow to ship quality code fast.
• Design and integrate AI-powered features with Product and Data teams.
• Engage in real code review and architectural sparring with peers.
• Hunt down gnarly bugs and turn learnings into reusable libraries.
• Spot scaling and reliability issues before they affect users.

Skills

Backend development

Product sense in 0→1 journey

Agile teamwork

AI/LLM feature design

Prompt engineering

MLOps mindset

Payments/fintech familiarity

Fluent in Spanish and English

Education

Bachelors in CS/CE or equivalent

Tools

Azure

LLM APIs

RAG pipelines

Vector databases

Job description

Get to know us:

Started in 2016, Frekuent is now the all-in-one payment and loyalty platform for unattended environments — 500+ clients, 100M+ transactions a year, 2.5M+ users across Spain, France, Italy, Portugal, and Singapore. We turn one-time buyers into lifetime clients with cashless, contactless, effortless payments: less friction, more reasons to come back.

2026 has been our biggest year yet — we've hyperscaled from 40 to 100+ people, with more hires on the way, and closed a €6M funding round to fuel what's next.

And we're just getting started — our goal is to become the default payment and loyalty layer behind every unattended transaction, everywhere.

Curious? Check us out at www.frekuent.com.

Why this role exists:

At Frekuent, we don't build backend systems for their own sake — we build the engine behind products people actually use. You'll join a lean, senior product engineering team where ideas move from a Slack thread to production in days, not quarters, and where every tool at your disposal — including the AI ones we build with daily — is treated as leverage, not overhead.

If you've outgrown "ticket-taking" backend work and want to be in the room when a feature gets conceived, not just when it gets assigned to you, this is that room.

What you'll actually do:

• Own features end-to-end: architecture, implementation, release, and the metrics that tell you whether it worked.
• Use AI-assisted development as a default part of your workflow — we optimize for shipping quality code fast, not typing it manually.
• Help design and integrate AI-powered features into our product — from LLM-backed workflows to smarter automation — alongside our Product and Data teams.
• Do real code review and architectural sparring with people who'll push back on your ideas (and will expect you to push back on theirs).
• Hunt down gnarly bugs and turn what you learn into reusable libraries, not tribal knowledge.
• Spot scaling and reliability problems before they page anyone at 2am.

What you bring:

• 3+ years building backend systems in production — ideally inside a product company, not only an agency or feature factory.
• You've been in the room for a product's 0→1 journey at least once: conception, build, ship, measure impact.
• Comfortable in agile teams that move fast and change scope when the data tells them to.
• Working knowledge of cloud infrastructure — Azure experience is a strong plus.
• Fluent in Spanish and English.
• A degree in Computer Science, Computer Engineering, or equivalent hands-on experience — we care more about what you've shipped than the paper.
• Have hands-on experience integrating LLM APIs, building RAG pipelines, or working with vector databases.
• Have experimented with prompt engineering or AI agent frameworks in a real product context.
• Have opinions about MLOps and can defend them.
• Have built or scaled payments or fintech infrastructure (a plus, not a requirement).

How we work:

• Fast, autonomous, low-bureaucracy — you'll manage your own priorities more than someone will manage you.
• We measure output, not hours in a chair.
• Resilience matters here — not "never taking no for an answer," but the steadiness to keep improving a system after the first two attempts didn't work.

What’s In It For You

A hybrid model that works – Enjoy the energy of our office 3 days a week and the flexibility of working remotely the other 2.

Flexible schedule – because we trust you to own your time and your outcomes.

Meal vouchers – Enjoy a monthly support of meal vouchers to make your workdays tastier.

Health & wellness – private health insurance and discounted gym memberships to keep both body and mind in top shape.

Learning & development – English classes and role-specific training, because your growth is part of our journey.

23 days of paid time off – plus local holidays, because great ideas need space to rest.

A dynamic, fast-growing environment – where each day is unique and every idea counts.

A collaborative mindset – surrounded by people who genuinely enjoy building together.

Regular afterwork & teambuilding events – activities to relax, connect, and strengthen team bonds.

If you're ready to jump into an exciting environment and make a real difference, this is the place for you.

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