Senior Full Stack Developer

Location: Justt TLV (IL)

Description

Justt is on a tear. We are reshaping a multi billion dollar problem with AI, our customer base is growing fast, and the momentum is real. Every quarter we are taking on bigger merchants, harder problems, and more interesting technical surface area. This is the moment to join a company that is past the "will it work" stage and squarely in the "how big can we go" stage.

You will work with sharp, ambitious people who care about what they ship. The product has clear customer impact, the roadmap is full, and your work will move metrics that matter to the business. If you are looking for a place where ownership is real, the pace is high, and your fingerprints will be all over the next chapter of the company, this is it.

What You Will Own

• Build and own complex integrations with merchants, processors, and third party APIs end to end
• Design and maintain the data pipelines that ingest and normalize customer data into Justt's schema
• Improve reliability and observability across our integrations to reduce reactive load
• Partner with Solutions Engineering on technical scoping for new customers
• Mentor developers and help shape the technical direction of the Integrations team

How You Work

We value engineers who:

• Take ownership end to end, from scoping through production support, without waiting for permission
• Communicate trade offs clearly, especially when timelines, scope, and technical reality are in tension
• Treat customer impact as a first class signal, not an afterthought
• Build systems that other people can run, debug, and extend
• Use AI tools as a force multiplier for drafting, synthesis, and triage, while still investing in deep system understanding

Requirements

• 5 to 8 years of full stack engineering experience, with a strong backend bias
• Deep experience with Node.js (TypeScript preferred) in production environments
• Solid React experience for building internal tools and customer facing surfaces
• Hands on experience with AWS (Lambda, ECS or EKS, S3, SQS or EventBridge, RDS or DynamoDB)
• Practical experience building scrapers or browser automation with Playwright, Puppeteer, or Selenium
• Strong fundamentals in API design (REST and webhook patterns), authentication, and error handling
• Track record of building observable systems with structured logging, metrics, and tracing
• Experience integrating with third party APIs at production quality, including rate limits, retries, idempotency, and reconciliation
• Clear written and verbal English, including the ability to translate technical risk into business language for non engineering partners

Nice to have

• Experience in payments, fintech, fraud, chargebacks, or any domain with high data sensitivity and regulatory pressure
• Experience working closely with Solutions Engineering, customer success, or other customer facing functions
• Experience with queue based and event driven architectures