Senior Fullstack Engineer (Kotlin/React)

Kunai builds full-stack technology solutions for banks, credit and payment networks, infrastructure providers, and their customers. Together, we are changing the world’s relationship with financial services. At Kunai, we help our clients modernize, capitalize on emerging trends, and evolve their business for the coming decades by remaining tech-agnostic and human-centered.

Overview

We are seeking a Senior Fullstack Engineer to support the design and delivery of secure, scalable, enterprise-grade applications within a large financial services environment. This role will be instrumental in modernizing and enhancing cloud-native platforms that power critical banking systems.

The ideal candidate brings deep expertise in Kotlin and Spring Boot, strong frontend capabilities with React and TypeScript, and hands-on experience operating containerized applications in AWS. This position requires a strong understanding of system reliability, security best practices, and performance optimization within highly regulated, large-scale environments.

Key Responsibilities

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Design, develop, and maintain secure, high-performance backend services using Kotlin and Spring Boot within a microservices architecture.

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Build and enhance modern, responsive user interfaces using React and TypeScript, ensuring accessibility and maintainability.

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Develop and maintain RESTful APIs that meet enterprise standards for scalability, reliability, and security.

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Deploy, manage, and monitor containerized applications using Amazon ECS (Elastic Container Service).

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Leverage core AWS services to design resilient, fault-tolerant cloud infrastructure aligned with enterprise architecture standards.

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Design, implement, and optimize relational database solutions using PostgreSQL and/or MySQL, including complex query development and performance tuning.

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Follow structured Git-based workflows using GitHub, including feature branching, pull request reviews, and controlled release processes.

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Ensure adherence to secure coding standards, compliance requirements, and enterprise governance frameworks.

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Identify and resolve system performance issues across application, database, and infrastructure layers.

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Participate in architectural reviews and contribute to long-term platform modernization initiatives.

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Collaborate with cross-functional stakeholders including product, security, DevOps, and enterprise architecture teams.

Required Qualifications

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5+ years of experience in fullstack software engineering within complex, enterprise environments.

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Strong backend development experience using Kotlin.

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Proven expertise developing production-grade microservices using Spring Boot.

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Hands-on experience with AWS (Amazon Web Services) and cloud-hosted infrastructure.

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Experience deploying and managing containerized workloads using Amazon ECS.

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Strong frontend development experience with React and modern JavaScript.

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Proficiency in TypeScript to enhance scalability, maintainability, and type safety.

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Solid understanding of relational database design and advanced SQL (PostgreSQL or MySQL).

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Experience with Git-based version control and enterprise development workflows using GitHub.

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Strong understanding of object-oriented design principles, design patterns, and distributed systems.

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Experience working in regulated or compliance-driven environments is highly preferred.

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Excellent communication skills and ability to collaborate across large, matrixed organizations.

Our success over the past 20 years is rooted in our exceptional team, which thrives in a culture of collaboration, creativity, and continuous learning.

We are proud to offer our employees a range of benefits, including competitive compensation, professional development opportunities, and flexible work arrangements, all designed to help them thrive. As we continue to expand, we remain committed to cultivating an environment where people feel valued, have a voice, and are given the tools to grow—both personally and professionally—while pushing the boundaries of innovation in the fintech industry.

Minimum Degree Required:

• Bachelor’s Degree, in lieu of a degree, demonstrating in addition to the minimum years of experience required for the role, three years of specialized training and/or progressively responsible work experience in technology for each missing year of college is required