Senior Software Engineer

Mambu Payments (formerly Numeral); Barcelona; Presencial; EUR 90.000 - 130.000; Jornada completa

Descripción de la vacante

Mambu Payments (formerly Numeral) is hiring Senior Backend Software Engineers to help build the next generation of bank connectivity and payment automation products with a focus on security, stability and performance.

You will own architectural decisions for high-impact projects, collaborate with Product Managers and DevOps, mentor engineers, and contribute to a fast-paced, evolving product in a cloud-native SaaS environment.

Formación

• 5+ years of professional software engineering experience, with significant hands-on Golang.
• Background in fintech, banking, or payments with regulatory understanding.
• Proven track record designing and owning complex distributed backend systems.
• Deep experience with relational databases and SQL in high-concurrency environments.
• Strong API design skills focusing on security, versioning and documentation.
• Mentor engineers and elevate engineering standards.
• Autonomous, proactive and able to resolve ambiguous technical problems.
• Curious, business-minded and product-oriented.

Responsabilidades

• Develop bank connectivity and payment automation products with focus on security, stability, and performance.
• Own architectural decisions for complex, high-impact projects and drive technical direction.
• Collaborate with Product Managers and DevOps to maintain a fast-paced, iterative delivery process.
• Apply security by design to public and internal APIs.
• Solve architectural and technical challenges to reduce complexity while creating value for customers and users.
• Mentor junior and mid-level engineers through code reviews, pair programming, and technical guidance.
• Define and execute Numeral's technical roadmap to improve team velocity and control technical debt.
• Act as a technical reference and escalation point for critical incidents and high-stakes production issues.

Conocimientos

Golang

Backend engineering

Distributed systems

Relational databases

SQL

APIs design

Security by design

Mentoring

Autonomy

Fintech/payments domain

Herramientas

GitLab CI

Kubernetes

AWS

Kafka

Descripción del empleo

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