Senior MERN Stack Developer (Backend Focus)

Position: Senior MERN Stack Developer (Backend Focus)
Location: Livingston NJ (Hybrid 3 Days Onsite)
Job Type: Long-Term Contract

STAFFXPERT LLC is seeking a Senior MERN Stack Developer (Backend Focus) on behalf of our client in Livingston NJ to join a growing fintech engineering team. This role is ideal for a highly experienced backend-focused engineer with deep expertise in building scalable APIs cloud-native applications and serverless backend systems.

The ideal candidate will bring strong experience with MongoDB RESTful API development and AWS serverless technologies. You will play a key role in designing and maintaining high-performance backend services that support large-scale integrations and mission-critical business operations. Exposure to Python-based development and emerging Generative AI initiatives is highly preferred.

• Design develop and maintain scalable high-performance RESTful APIs for enterprise-grade integrations.

• Build secure reliable and efficient backend services using and Python.

• Develop and support cloud-native applications leveraging AWS serverless architecture including:

  • AWS Lambda

  • AWS Step Functions for workflow orchestration and service coordination

• Contribute to a platform enabling self-service API capabilities for a broad ecosystem of external consumers.

• Deliver end-to-end backend features independently in a fast-paced agile environment.

• Collaborate cross-functionally with engineering teams to drive technical excellence and knowledge sharing.

• Support platform enhancements and integrations related to Generative AI initiatives.

• Participate in architecture discussions code reviews and backend optimization efforts.

• 7 years of backend software development experience.

• Strong hands-on expertise in and MongoDB.

• Extensive experience designing and building RESTful APIs.

• Proficiency in Python with strong understanding of Object-Oriented Programming (OOP) concepts.

• Experience working with both SQL and NoSQL databases.

• Strong experience with the MERN Stack with a clear emphasis on backend-heavy development.

• Hands-on expertise with AWS Lambda and serverless application architecture.

• Ability to work independently and succeed in a high-velocity engineering environment.

• Excellent communication collaboration and problem-solving skills.

• Bachelors degree in Computer Science Engineering or a related technical field.

• Experience supporting or integrating Generative AI solutions.

• Prior experience in fintech or high-scale transactional systems is a plus.

• Familiarity with scalable distributed systems and API platform engineering.