Senior Backend Engineer

Job Description: Backend Engineer

Location: Remote

Company: ONEngine.ai

Reports To: Backend Lead Engineer

Salary: Competitive, commensurate with experience

Position Overview

We are seeking an accomplished Senior Backend Engineer to drive the development of our enterprise-grade, multi-tenant SaaS platform. You will be responsible for designing and implementing complex backend features, contributing to architectural decisions, and ensuring code quality and scalability across the platform. Working collaboratively with product, frontend, and infrastructure teams, you will serve as a technical expert and mentor to other developers while championing best practices in modern serverless backend development.

Key Responsibilities

• Design and develop sophisticated backend features using Node.js 20+ and TypeScript with advanced patterns and performance optimization
• Build and maintain scalable multi-tenant backend architectures with proper tenant isolation, data security, and compliance measures
• Architect modular, maintainable services following SOLID principles and enterprise design patterns
• Design and implement complex database schemas and queries using Prisma ORM and PostgreSQL, ensuring optimal performance
• Design and implement RESTful APIs consumed by React frontends, ensuring data integrity, security, and exceptional developer experience
• Build serverless applications using AWS Lambda, API Gateway, SQS, EventBridge, and other AWS services
• Implement authentication and authorization flows (JWT, OAuth) with proper security measures
• Implement audit logging systems and compliance requirements for enterprise clients
• Perform advanced debugging, write comprehensive tests, and optimize application performance
• Mentor junior and mid-level engineers through code reviews, pair programming, and knowledge sharing
• Participate in architectural discussions and provide technical recommendations to the Lead Engineer and CTO
• Collaborate cross-functionally to translate complex requirements into elegant, scalable technical solutions
• Contribute to migration efforts from legacy Java systems to modern Node.js/TypeScript architecture
• Stay current with backend technology trends and evaluate new tools and frameworks for team adoption

Ideal Candidate Profile

Education: Bachelor's or Master's degree in Computer Science, Engineering, or related field

Experience: - 4-6 years of professional backend development experience with strong focus on Node.js and TypeScript

- 2+ years building production APIs with TypeScript and Node.js

- 2+ years hands-on experience with AWS Lambda and serverless architecture (Lambda, API Gateway, SQS, EventBridge)

- 2+ years building/operating multi-tenant SaaS systems with tenant isolation

- Proven track record of delivering complex features in enterprise or multi-tenant applications - Experience working in agile environments with cross-functional teams

- Demonstrated ability to mentor developers and contribute to technical leadership

Skills: - Expert-level proficiency in TypeScript and Node.js, including advanced patterns and performance optimization

- Strong hands-on experience with AWS Lambda and serverless technologies (API Gateway, SQS, EventBridge)

- Deep understanding of multi-tenant SaaS architecture including tenant isolation, data security, and scalability

- Advanced knowledge of PostgreSQL including complex queries, optimization, and schema design

- Extensive experience with Prisma ORM or similar ORMs for database interactions

- Strong experience designing scalable, well-documented RESTful APIs

- Solid experience with authentication flows (OAuth, JWT) and security best practices

- Experience with Express or similar Node.js frameworks

- Working knowledge of S3 and document/file management systems

- Strong testing methodology including unit, integration, and end-to-end testing

- Experience with CI/CD pipelines and backend deployment strategies

- Familiarity with message queues and event-driven architectures

- Experience with audit logging and compliance requirements is a plus

- React/frontend experience for full stack collaboration is a plus

- Experience with AI/ML API integrations is a plus

- Field service management or B2B SaaS background is a plus

- AWS certifications are a plus

- Excellent problem solving, communication, and collaboration skills

- Passion for code quality, performance, and system reliability

Tech Stack

TypeScript, Node.js 20+, AWS Lambda, API Gateway, SQS, EventBridge, PostgreSQL, Prisma ORM, Express, S3, React (frontend team

Job Types: Full-time, Permanent

Benefits:

• Work from home

Please note that ONEngine is currently unable to provide visa sponsorship for this position. Candidates must be authorized to work in Ireland without sponsorship now or in the future.

Pay: €55,000.00-€85,000.00 per year

Benefits:

• Work from home

Application question(s):

• Are you an Irish citizen?

Experience:

• TypeScript: 1 year (preferred)
• Node.js: 1 year (preferred)
• AWS Lambda: 1 year (preferred)
• PostgreSQL: 1 year (preferred)
• Prisma ORM: 1 year (preferred)
• Express: 1 year (preferred)
• S3: 1 year (preferred)
• Eventbridge: 1 year (preferred)

Work Location: Hybrid remote in Dublin, County Dublin