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Senior Software Engineer

Barcelona💼 Full-time🗓 2026-04-20 → 2026-09-23

Core

Design, develop, and maintain backend services and API integrations for the eSim product offering in the FinTech/telecom sector.

Role type

Senior Software Engineer (Backend)

Builds

eSim product features and core platform services for telecom operators and end-users

Domain

FinTech / Telecommunications

Deliverable

production ML models | product features

Required skills

Spring Boot, Java, Kotlin, REST APIs, SQL, distributed systems, asynchronous/event-driven patterns, CI/CD, Git, AWS

Preferred skills

Telecommunications protocols (Gx/Gy/DIAMETER, SMPP), OAuth2/OIDC, OpenAPI/Swagger, MariaDB, JPA/Hibernate, Docker, Kubernetes, GoLang, Python, Perl, GCP

Technologies

Spring Boot, Java, Kotlin, AWS, MariaDB, Docker, Kubernetes, GoLang, Python, Perl, GCP

Responsibilities

Design and develop Spring Boot services; Build and support API integrations across telecom systems; Work with asynchronous/event-driven flows; Improve reliability, performance, and observability of backend services; Collaborate with product and engineering teams to ship features

Seniority

Senior, hands-on IC

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