Senior Full-Stack Engineer (with AI agents experience)

N-iX; Town of Poland (NY); Hybrid; USD 100,000 - 180,000; Full time

Benefits offered by this job

Flexible working format

Competitive salary

Career growth

Education reimbursement

Tech talks & trainings

Team events

Job summary

N-iX, a global software development partner, seeks a Senior Full-Stack Engineer to work across Kotlin backend and React/TypeScript frontend. You will balance front-end and back-end depth and move between layers to unblock delivery in a fast-paced fintech environment.

You'll collaborate in AWS-based infra, contribute to AI-native delivery practices, and embed in client squads as an individual contributor. Flexible remote/office options and strong career growth await.

Qualifications

• Must have Kotlin backend and React/TypeScript frontend experience.
• Experience applying AI-native delivery practices across the CDLC.
• Clear leaning toward frontend or backend depth with ability to move across stack layers.
• Experience with AWS.
• Evidence of building/operating tooling (agent & harness).

Responsibilities

• Deliver across the Kotlin backend and React/TypeScript frontend.
• Move fluidly between stack layers to unblock delivery.
• Apply AI-native delivery practices across the CDLC.
• Multiply output and quality of the squad and share patterns widely.
• Embed directly into a client squad as an hands-on Individual Contributor.

Skills

Kotlin (backend)

React/TypeScript (frontend)

AI-native delivery

Frontend/backend depth

AWS

Tooling & harnessing

Tools

PostgreSQL

Job description

N-iX is a global software development service company that helps businesses across the globe create next-generation software products. Founded in 2002, we unite 2,400+ tech-savvy professionals across 40+ countries, working on impactful projects for industry leaders and Fortune 500 companies. Our expertise spans cloud, data, AI/ML, embedded software, IoT, and more, driving digital transformation across finance, manufacturing, telecom, healthcare, and other industries. Join N-iX and become part of a team where your ideas make a real impact.

About the Client

Our client is a fast-growing European fintech company in the business spend management space — corporate cards and related financial products — serving SME and mid-sized business customers across the EU and UK, in a regulated environment with GDPR compliance obligations. Engineering is organized into cross-functional squads, with platform/enabling teams providing shared tooling horizontally. The client already runs an AI-native engineering practice: Claude Code and GitHub Copilot are used daily, supported by a growing library of shared, versioned Skills embedded in key repositories, enabling an end-to-end flow from ticket to implementation, testing and PR in several codebases. AI tool/connector rollout follows an approved-list and pilot process. The client is AWS-first overall; for data platform and analytics workloads it also runs GCP, with BigQuery as the primary data warehouse. Day-to-day coordination is Slack-first, with Linear for ticket tracking, GitHub for code/PR review, and Notion as the knowledge base.

About the Role

We're looking for a Senior Full-Stack Engineer working across the Kotlin backend and React/TypeScript frontend, with a clear leaning toward either front-end or back-end depth and the ability to move fluidly between layers to unblock delivery.

Key Responsibilities

• Deliver across the Kotlin backend and React/TypeScript frontend
• Move fluidly between stack layers to unblock delivery
• Apply AI-native delivery practices across the CDLC
• Multiply the output and quality of the squad you join, and share patterns/practice beyond your immediate team so adoption compounds across the organisation
• Embed directly into a client squad as a hands-on Individual Contributor (not a coaching/managerial role).

Must-Have Skills

• Kotlin (backend) and React/TypeScript (frontend)
• AI-native delivery practices applied across the CDLC
• A clear leaning toward front-end or back-end depth, with the ability to move fluidly across stack layers
• Experience with AWS
• Agent & harness engineering fluency, with concrete evidence of building/operating this kind of tooling, not just using it.

Nice-to-Have Skills

• PostgreSQL

We offer*

• Flexible working format - remote, office-based or flexible
• A competitive salary and good compensation package
• Personalized career growth
• Professional development tools (mentorship program, tech talks and trainings, centers of excellence, and more)
• Active tech communities with regular knowledge sharing
• Education reimbursement
• Memorable anniversary presents
• Corporate events and team buildings
• Other location-specific benefits
• not applicable for freelancers