We’re hiring

4 Backend Engineers (Mid, Senior, and Staff levels)

to join a high-impact

API Platform team

building scalable, self-serve infrastructure used by both customers and internal product teams.

This is a rare opportunity to join a

fast-growing fintech environment

where the API is a

top business priority

and sits at the core of the company’s platform modernisation strategy.

Location Madrid (Hybrid:

4 days in office / 1 day remote )

Salary €40K – €90K + bonus + benefits (depending on experience level: Mid / Senior / Staff)

About the team You’ll join an

API Platform team

focused on: Building a

modern, scalable API surface

used by external clients and internal teams Creating

self-service capabilities , including instant API credential provisioning Launching and expanding a

new API sandbox environment for clients Improving

performance, observability, reliability, and developer experience Building foundations for

AI-driven workflows via API integrations (MCP / agentic interfaces) Supporting platform modernization and service decomposition at scale

The API is evolving into a

product in itself , with strong visibility across engineering and the business.

️ Tech environment You don’t need to know everything, but experience in similar ecosystems is key: Backend:

Python, Django, REST APIs Data:

PostgreSQL, Redis Infrastructure:

AWS, Docker, Kubernetes, Terraform Identity / access: IAM concepts (Keycloak or similar is a plus) Strong engineering fundamentals: system design, OOP + functional design,



clean architecture CI/CD, observability, monitoring, and production ownership mindset

What you’ll do Depending on your level, you will: Design and build scalable backend services and APIs Own services end-to-end (“you build it, you run it”) Contribute to architecture decisions via RFC process Improve platform reliability, latency, and developer experience Mentor more junior engineers (Senior+ levels) Help shape a modern platform used at general scale

What we’re looking for Strong software engineering fundamentals (algorithms, design patterns, architecture) Experience building

production-grade distributed systems Comfortable working in

cloud-native environments Strong communication skills in English (international teams) Ownership mindset and ability to thrive in ambiguity Fintech experience is

highly valuable

Growth & impact First 3–6 months: contribute to building new platform components from scratch 12 months: ownership of a key platform area + influence across teams Clear performance framework and quarterly career development reviews High visibility role in a

strategic engineering initiative

About E-Frontiers We are a

specialist tech recruitment partner

working with leading product companies and fintech organisations across Europe. We focus on connecting strong engineering talent with

high-impact roles where they can grow and build meaningful products .

If you’re interested or know someone who could be a fit, feel free to reach out directly or send your CV.

📌 Backend / API Engineers (Mid to Staff level) – Fintech Platform (Madrid / Hybrid)
🏢 E-Frontiers
📍 Madrid