Join the fintech revolution with Mambu, the leading SaaS cloud banking platform. We're on a mission to make banking better for a billion people. We're engineering the future of financial services with AI at its core. At Mambu, AI isn't a feature — it's how we're rebuilding banking from the ground up. If you're ready to apply cutting-edge technology to problems that affect millions of people, your next chapter starts here. Learn more here .

We are hiring

Senior Backend Software Engineers across all teams. As a Senior Backend Software Engineer, you will be responsible for:

Developing bank connectivity and payment automation products, features, and capabilities, with a focus on security, stability, and performance

Owning architectural decisions for complex, high-impact projects and driving technical direction across teams

Collaborating with Product Managers and DevOps Software Engineers to maintain a fast-paced, iterative, and continuously improved product development and delivery process

Applying security by design principles to public and internal APIs

Solving architectural and technical challenges to reduce complexity while creating value for customers and users

Mentoring and upskilling junior and mid-level engineers through code reviews, pair programming, and technical guidance

Defining and executing Numeral's technical roadmap to improve team velocity and control technical debt





Acting as a technical reference and escalation point for critical incidents and high-stakes production issues.

5+ years of professional software engineering experience, with significant hands‑on experience in Golang

Background in fintech, banking, or payments (SEPA, Swift, Ebics…), with an understanding of the regulatory and operational constraints of the industry

Proven track record designing and owning complex, distributed backend systems in production

Deep experience with relational databases and SQL, including high-concurrency environments, transaction management, and isolation levels at scale

Strong understanding of the challenges of running a high-volume SaaS platform at scale, with a track record of producing quality, maintainable, well-documented code that respects best practices

Advanced API design skills, with a strong focus on security, versioning, and documentation

Demonstrated ability to mentor engineers and elevate team-wide engineering standards

You are curious, interested in business understanding and product oriented

You are highly autonomous, proactive, and comfortable driving ambiguous technical problems to resolution

Nice-to-have skills

DevOps appetite - you have been in involved in implementing / using CI using Gitlab and Kubernetes

Cloud hosting with AWS and experience with EC2, S3, EKS, RDS…

Familiar with Kafka or similar message broker middlewares

📌 Senior Software Engineer (Madrid)
🏢 Mambu Payments (formerly Numeral)
📍 Madrid