Senior Backend Engineer (Tech Lead)

O projekcie:
On behalf of Sunbit, SD Solutions is looking for a talented Backend Engineer.

As a Backend Engineer, you will design, develop, and maintain robust server-side systems that power our financial technology products. You will focus on building scalable, secure, and high-performance backend services, handling critical data processing, API development, and integration with various systems. Working closely with frontend engineers, product managers, and other stakeholders, you will contribute to delivering reliable solutions that enhance user experience and support key business objectives in a fast-paced fintech environment.


SD Solutions is a staffing company operating globally. Contact us to get more details about the benefits we offer.


About the company:


Sunbit, builds financial technology for real life. Our technology eases the stress of paying for life’s expenses by giving people more options on how and when they pay. Founded in 2016, NDA, FinTech offers a next-generation, no-fee credit card that can be managed through a powerful mobile app, as well as a point-of-sale payment option available at more than 25,000 service locations, including auto dealership service centers, optical practices, dentist offices, veterinary clinics, and specialty healthcare services

Wymagania:
Requirements:
- 7+ years of professional experience as a Backend Engineer (or similar role) building scalable server-side applications.- Strong proficiency in at least one modern backend language such as Java or Kotlin.- Solid experience with microservices architecture and distributed systems.- Experience in domain ownership - a must.- Hands-on experience with relational databases (e.g., MySQL, PostgreSQL) and non-relational databases (e.g., MongoDB, DynamoDB).- Experience with AI tools and a strong interest in continuously exploring and applying them in everyday work are highly valued.- Familiarity with message queue / streaming technologies such as Kafka, RabbitMQ, SQS, or similar.- Good understanding of cloud platforms (preferably AWS or similar), including services for compute, storage, and networking.- Experience building secure, high-performance APIs and handling sensitive data (especially valuable in fintech).- Strong problem-solving skills, attention to detail, and ability to work effectively in a fast-paced, collaborative environment.- Excellent communication skills and fluency in English.- B.Sc. in Computer Science or equivalent practical experience.
Preferred Experience:

- Expertise in Spring Framework (Spring Boot).- Experience with fintech or payment processing systems, compliance requirements (e.g., PCI DSS), or secure transaction handling.- Familiarity with containerization (Docker) and orchestration (Kubernetes).- Knowledge of CI/CD pipelines and infrastructure as code.- Exposure to modern development tools and practices (e.g., Git, automated testing, observability tools).

Codzienne zadania:
- Design and implement scalable backend architecture, services, and APIs for core financial products and features.
-   Develop high-quality, maintainable server-side code with a strong emphasis on performance, reliability, and security.
-   Build and maintain RESTful APIs (and potentially GraphQL) to support mobile and web applications.
-   Manage databases (relational and non-relational), optimize queries, and ensure data integrity and consistency.  Collaborate with cross-functional teams (frontend, product, QA, DevOps) to translate business requirements into technical solutions.
-   Participate in code reviews, write unit/integration tests, and contribute to improving engineering practices.
-   Monitor system performance, troubleshoot production issues, and participate in on-call rotations as needed.
-   Contribute to continuous improvement by refactoring legacy code, adopting best practices, and staying current with relevant technologies.