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 integral 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