Middle Full-Stack Engineer

OpenKrill; United States; On-site; USD 67,000 - 101,000; Full time

Benefits offered by this job

Paid time off

Private health insurance

FitPass

Learning resources

Team events

Culture of trust

Job summary

Openkrill is seeking a Middle Full-Stack Engineer to join the AI & Automation Engineering team. You will work on the Internal Operational Platform, a growing product that automates workflows across multiple departments.

The role emphasizes backend and integration with an established tech stack, collaborating with engineers and business stakeholders in a fast-evolving product environment. The position involves building RESTful services, database design with PostgreSQL, and front-end work using

Qualifications

• Proven experience building full-stack apps with Java/Spring Boot and React/TypeScript.
• Strong backend and data integration capabilities (PostgreSQL, APIs, data schemas).
• Experience with OpenAPI-driven development and API clients.

Responsibilities

• Build and maintain full-stack applications using Java/Spring Boot and React/TypeScript.
• Develop new functionality for the Internal Operational Platform and support existing apps as the platform expands.
• Refactor prototype logic into clean backend services and typed APIs.

Skills

Java

Spring Boot

REST APIs

PostgreSQL

Maven

Liquibase

Spring Security

OpenAPI

React

TypeScript

TanStack Query

BigQuery

Tools

Liquibase

Job description

We are looking for a Middle Full-Stack Engineer to join our AI & Automation Engineering team and work on our Internal Operational Platform — a growing product designed to automate workflows across multiple departments at AI Digital.The platform is being developed as a central place where teams can access tools supporting their internal processes. The team is currently expanding its functionality, supporting existing applications, and gradually bringing more workflows from different departments onto the platform.This is a hands-on full-stack engineering role with a strong backend and integration focus, within an established engineering stack and in close collaboration with engineers and business stakeholders as the platform continues to evolve.

Responsibilities

• Build and maintain full-stack applications using Java/Spring Boot and React/TypeScript.
• Develop new functionality for our Internal Operational Platform and support existing applications as the platform continues to expand.
• Transform AI-generated and vibe-coded MVPs into reliable, production-ready applications while preserving the original product intent.
• Refactor prototype logic into clean backend services, typed APIs, PostgreSQL schemas, and maintainable frontend workflows.
• Design and implement PostgreSQL schemas and manage database migrations with Liquibase.
• Develop REST APIs following an OpenAPI contract-first approach and work with typed frontend API clients.
• Integrate applications with BigQuery and support reliable data publishing and integration flows.
• Implement and maintain backend observability using Spring Boot Actuator, Prometheus metrics, and structured logging.
• Contribute to application quality through testing, monitoring, maintenance, and production support.
• Collaborate with business stakeholders and other engineers to translate real workflows into practical technical solutions.
• Backend: Solid experience with Java, Spring Boot, REST APIs, PostgreSQL, Maven, Liquibase, Spring Security, and OpenAPI-based development.
• Front-end: Practical experience with React and TypeScript, API-driven interfaces, and server-state management such as TanStack Query.
• Data & Integration: Experience with BigQuery or another data warehouse and integrating applications with external APIs and data sources.
• Production Engineering: Good understanding of authentication, persistence, logging, monitoring, testing, and maintainability.
• AI-Assisted Development: Hands‑on experience with tools such as Cursor, Claude/Anthropic, OpenAI, Replit AI, or similar, including reviewing and improving AI-generated code.
• Comfortable collaborating with both engineers and business stakeholders in an evolving product environment.
• English level B2 or higher.
• Strong verbal and written communication skills.

What We Offer

• 31 days of paid time off: 21 days of annual leave + 10 days of sick leave, because your health and work-life balance matter.
• Private health insurance and FitPass: supporting your well-being both inside and outside of work.
• Growth-focused environment: access to learning resources and clear pathways for growth.
• Fun team events: virtual cooking classes, yoga sessions, team quizzes and more.
• A culture of trust: we cut the red tape — results over rules always. Open talk, ownership, and getting things done together.

Hiring Flow

• Screening Interview (45 minutes): initial conversation with a recruiter.
• Technical Interview (up to 120 minutes): A deep dive into your functional expertise, problem-solving approach, and practical skills relevant to the role.
• Final Interview (Up to 60 minutes): Meet with the Team Lead for an in-depth discussion of your experience and skills.
• Offer: if successful, you’ll receive an offer to join our team.

Location & Eligibility

This role is open to applicants from Serbia.Please note that we’re unable to consider applications from outside these locations.Thanks for your understanding!