Job Title: Senior Fullstack Engineer

Company Name: Kunai

Job Url: https://wellfound.com/jobs/3941021-senior-fullstack-engineer-kotlin-react

Job Description: 
Kunai
Actively Hiring
Digital product agency working with Fortune 500 companies & unicorn startups for 20+ years
B2B
Growth Stage
Growing fast
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Senior Fullstack Engineer (Kotlin/React)
$50k – $200k
|
Remote (
United States
)
|Full Time
Posted: today• Recruiter recently active
Hires remotely in
United States
Visa Sponsorship
Not Available

Relocation
Not Allowed
About the job
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
Design, develop, and maintain secure, high-performance backend services using Kotlin and Spring Boot within a microservices architecture.
Build and enhance modern, responsive user interfaces using React and TypeScript, ensuring accessibility and maintainability.
Develop and maintain RESTful APIs that meet enterprise standards for scalability, reliability, and security.
Deploy, manage, and monitor containerized applications using Amazon ECS (Elastic Container Service).
Leverage core AWS services to design resilient, fault-tolerant cloud infrastructure aligned with enterprise architecture standards.
Design, implement, and optimize relational database solutions using PostgreSQL and/or MySQL, including complex query development and performance tuning.
Follow structured Git-based workflows using GitHub, including feature branching, pull request reviews, and controlled release processes.
Ensure adherence to secure coding standards, compliance requirements, and enterprise governance frameworks.
Identify and resolve system performance issues across application, database, and infrastructure layers.
Participate in architectural reviews and contribute to long-term platform modernization initiatives.
Collaborate with cross-functional stakeholders including product, security, DevOps, and enterprise architecture teams.
Required Qualifications
5+ years of experience in fullstack software engineering within complex, enterprise environments.
Strong backend development experience using Kotlin.
Proven expertise developing production-grade microservices using Spring Boot.
Hands-on experience with AWS (Amazon Web Services) and cloud-hosted infrastructure.
Experience deploying and managing containerized workloads using Amazon ECS.
Strong frontend development experience with React and modern JavaScript.
Proficiency in TypeScript to enhance scalability, maintainability, and type safety.
Solid understanding of relational database design and advanced SQL (PostgreSQL or MySQL).
Experience with Git-based version control and enterprise development workflows using GitHub.
Strong understanding of object-oriented design principles, design patterns, and distributed systems.
Experience working in regulated or compliance-driven environments is highly preferred.
Excellent communication skills and ability to collaborate across large, matrixed organizations.