Senior Software Engineer

Company: ZealTech

Location: Newark, CA

Posted on: June 16

Job Title: Senior Software Engineer TypeScript to Java

(Full-Time - W2 only)

(H1B transfer ok)

Location: Client location - Newark, CA (Hybrid)

Duration: 612 months (with potential extension/full-time)

Experience Level: 1015 Years

Start Date: ASAP

About the Role

Were looking for a hands-on, senior-level engineer with a proven track record of large-scale, complex system migrationsspecifically from NestJS/TypeScript to Java. Youll play a mission-critical role in helping us re-architect and rebuild a key part of our platform, ensuring performance, maintainability, and scalability as we shift our backend foundation.

This is not a hand-holding role. We want someone who:

• Owns the outcomes, not just the code.
• Can hit the ground running with minimal onboarding
• Thrives in ambiguous, high-impact environments.

Key Responsibilities

• Lead the end-to-end migration from a NestJS/TypeScript backend to a Java-based architecture.
• Translate business-critical features from the old system into clean, performant, scalable Java code.
• Collaborate closely with product managers, engineers, and DevOps to ensure a smooth transition with minimal disruption.
• Define and execute migration strategy, tooling, automation, and phased rollout plans.
• Work directly with SQL databases to map, migrate, and optimize schema and queries as needed for the new Java-based system.
• Ensure backwards compatibility (where needed) and guide system integration testing.
• Identify architectural improvements and technical debt, and build long-term foundations during the migration.

Required Experience

• 1015 years of backend engineering experience, with at least 2 large-scale system migrations completed.
• Deep hands-on expertise in Java (Spring Boot preferred) and TypeScript/NestJS.
• Strong SQL database experienceyou can read, write, refactor, and optimize complex queries and schemas (PostgreSQL or MySQL preferred).
• Excellent understanding of backend architecture, REST APIs, data modeling, and cloud-native systems.
• Experience designing for performance, reliability, and maintainability at scale.
• Ability to work independently, take end-to-end ownership, and communicate clearly across teams.

Nice to Have

• Experience with microservices, message queues, and distributed systems.
• Familiarity with CI/CD pipelines, observability tooling, and containerized deployments (Docker, Kubernetes).
• Experience working with ORMs in both TypeScript and Java environments (TypeORM, Hibernate, etc.).
• Prior exposure to high-availability or regulated system environments.