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Senior Fullstack Engineer

Justt

Justt

Software Engineering
Copenhagen, Denmark · Tel Aviv-Yafo, Israel · Ezor Tel Aviv, Israel
Posted on Dec 3, 2025

Senior Fullstack Engineer

  • Engineering & Data
  • Justt TLV

Description

Justt helps many of the world’s largest and most recognizable brands turn chargebacks from a constant headache into a managed, predictable part of doing business. Our AI-driven platform powers chargeback operations at scale, automating disputes end to end, recovering revenue that would otherwise be lost, and removing a major operational burden from finance, risk, and operations teams across multiple regions and verticals.

We’re a global company with teams across markets, and disciplines, working closely with leading players in the payments ecosystem. Our culture is built on clear thinking, collaboration, and a strong sense of ownership. At Justt, you’ll partner with product, engineering, data, success and go-to-market teams to build technology that sits at the core of modern payments, and has a direct, measurable impact on the bottom line for some of the biggest companies in the world.

What you'll be doing:

  • Own features end-to-end in our chargeback automation platform - from AI-powered evidence generation to real-time merchant-facing insights
  • Take features from concept to production - plan, build, deploy, and monitor your code in production
  • Master our tech stack (Node.js, Next.js, SQL/NoSQL, K8S, AWS) while building features across our 200+ microservices architecture
  • Handle high-stakes data at scale - process thousands of chargebacks daily, ensure data accuracy, and maintain system reliability
  • Be part of a strong engineering culture - work closely with engineers, product, QA, and DevOps to ship features that move the needle

Requirements

  • 5+ years of hands-on experience in full stack software development
  • Strong experience with Node.js and React (experience with Nest.js or Next.js is an advantage)
  • Experience with both SQL & NoSQL databases (MongoDB, PostgreSQL, Redis, or similar)
  • Hands-on experience implementing RESTful APIs and working with asynchronous execution environments
  • Familiarity with microservices architecture and containerization (Docker/Kubernetes)
  • Experience with cloud platforms (AWS preferred)
  • Experience with event-driven systems - Advantage
  • Experience with Monorepo - Advantage
  • Prior experience in a high-scale, production system - Advantage
  • Excellent team player with strong communication skills
  • Bachelor's degree in Computer Science, Software Engineering, or a related field
  • Drive to promote quality and continuous improvement