Senior Java Developer
First seen by Alion on Oct 23, 2026.
We’re looking for a Senior Back End Engineer to join a B2B SaaS platform powering 1M+ live websites for tens of thousands of businesses worldwide.
The product combines a large-scale distributed architecture with AI-powered tools for content generation, SEO, translations, image descriptions, and automated website updates. You’ll work on core services where performance, concurrency, reliability, and scalability are critical.
What you’ll do:
Build and scale core backend services with Java and Spring Boot.
Design distributed microservices and high-performance APIs.
Solve complex multithreading, concurrency, and performance challenges.
Work with relational and NoSQL databases and optimize data models.
Own features end-to-end, from requirements to production.
Use AI-powered development tools to improve engineering productivity.
Influence architecture and infrastructure decisions and mentor other engineers.
What we’re looking for:
5+ years of backend development experience.
Strong Java, Spring, and Spring Boot skills.
Deep understanding of multithreading, concurrency, and performance optimization.
Advanced, daily hands-on use of AI development tools such as Claude Code, Cursor, Codex, or similar, with practical experience integrating AI into real development workflows.
Ability to critically evaluate AI-generated code, make sound technical decisions, and maintain high engineering standards.
Experience with distributed systems, microservices, and API design.
Strong database and SQL skills.
Experience with unit and integration testing.
Ability to take ownership and work independently in a cross-functional team.
Strong communication skills and the ability to collaborate effectively in English.
Nice to have: TypeScript/React, Generative AI development tools, CI/CD, or experience in high-growth B2B SaaS.