Senior Backend Engineer (Kotlin) for ML-Powered APIs

NTT DATA Europe & Latam; Emilia-Romagna; On-site; EUR 85,000 - 110,000; Full time

Job summary

NTT DATA Europe & Latam seeks a Senior Backend Software Engineer to design, build, and operate backend services for an internal platform enabling personalised customer experiences using decisioning and ML. Focus on Kotlin, APIs, PostgreSQL, cloud technologies, streaming, and distributed data processing.

The role emphasizes architecture, mentoring, client-facing delivery, and collaboration with frontend and data teams to deliver end-to-end backend capabilities.

Qualifications

• 6/8+ years of experience in software engineering.
• Strong backend development experience with Kotlin and Ktor, Java, or another modern JVM language.
• Experience designing, delivering, and maintaining production APIs and distributed services.
• Strong relational database and SQL capability, including data modelling, schema evolution, and query or performance considerations.
• Experience with asynchronous programming, concurrency, event streaming, or resilient integration patterns.
• Experience developing and operating cloud-native applications using containers, managed services, identity, networking, observability, and infrastructure-as-code such as Terraform.
• Evidence of automated testing and responsibility for software quality.
• Evidence of independently owning substantial backend work and making sound trade-offs between delivery, maintainability, reliability, and performance.
• Designing stable service interfaces and integration contracts for use by frontend, data, or downstream systems.
• Experience contributing to design decisions, code reviews, technical documentation, troubleshooting, and the development of other engineers.

Responsibilities

• Design, build, maintain, and operate backend services and REST APIs using Kotlin and Ktor.
• Own backend-led work from discovery and domain design through implementation, automated testing, deployment, observability, production support, and iteration.
• Model and manage data in PostgreSQL, including schema design, queries, performance tuning, and database migrations.
• Use Terraform to define, provision, and manage cloud infrastructure as code.
• Build event-driven and batch data-processing workflows.
• Collaborate with data scientists and adjacent teams on reliable integrations with internal services, data platforms, and machine-learning systems.
• Improve service resilience, security, logging, metrics, tracing, and operational tooling.
• Use unit, property-based, integration, contract, behaviour-driven, and end-to-end testing where appropriate.
• Contribute to technical design, code reviews, documentation, and the maintainability of a large codebase.
• Design stable interfaces and integration contracts that enable frontend, data, and downstream teams to deliver end-to-end capabilities.
• Work directly with client stakeholders and delivery partners as requirements evolve, explaining technical trade-offs and adapting backend scope without compromising reliability, maintainability, or operational quality.

Skills

Backend development

API design

Distributed systems

SQL proficiency

Testing

Cloud-native apps

Kotlin experience

Client-facing delivery

Education

BSc/MSc in Computer Science

Tools

Ktor

Java

Terraform

Kafka

Spark

PostgreSQL

GitLab CI/CD

OpenTelemetry

Job description

NTT DATA Europe & Latam seeks a Senior Backend Software Engineer to design, build, and operate backend services for an internal platform enabling personalised customer experiences using decisioning and ML. Focus on Kotlin, APIs, PostgreSQL, cloud technologies, streaming, and distributed data processing.

The role emphasizes architecture, mentoring, client-facing delivery, and collaboration with frontend and data teams to deliver end-to-end backend capabilities.