Senior Software Engineer - Java

Sinch

Madrid, Spain

Description

About the Role

As a Senior Backend Engineer, you will be a key player in developing and scaling the Contacts and Inbox services within the SaaS Engage Platform at Sinch. You will be part of a cross-functional, autonomous team that sets its own goals and is responsible for every stage of the software development lifecycle – from design to deployment and maintenance.

Your focus will be on building high-impact, scalable, and distributed backend services, ensuring reliability, performance, and extensibility. The code you develop will power critical messaging and engagement functionalities across different product lines.

What You’ll Do

Work across the entire development lifecycle, from planning, design, and implementation to deployment, monitoring, and maintenance.
Design highly available, distributed, and event-driven microservices using Java.
Optimize and fine-tune performance in high-throughput, real-time messaging systems.
Implement and enhance APIs, messaging pipelines, and data models for seamless user interactions.
Work with non-relational databases like MongoDB, ensuring efficient data storage and retrieval.
Collaborate closely with frontend engineers, product managers, and other stakeholders to define product requirements and deliver high-quality features.
Ensure scalability, security, and observability of services while following best practices in software development.
Participate in code reviews, mentoring, and technical discussions to elevate the engineering culture.
Take full ownership of your code - you build it, you run it.

Requirements

What We Look For

6-8 years of backend development experience, with strong expertise in Java.
Solid understanding of microservices architecture and distributed systems.
Hands-on experience with non-relational databases (MongoDB preferred).
Familiarity with event-driven architectures and message queues like Kafka.
Strong problem-solving and architectural decision-making skills.
Experience designing RESTful APIs and working with cloud-native applications.
Ability to write clean, testable, and maintainable code with a focus on performance and reliability.
Comfortable working in an autonomous, fast-paced, and multicultural team environment.
Fluency in English (both written and spoken).