Backend Engineer — AI-Driven Payments Platform (Hybrid)

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

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.