Backend Engineer, LLM Applications - Newton, MA

Kelly Services; Newton (MA); Hybrid; USD 127,000 - 220,000; Full time

Benefits offered by this job

Medical Insurance

Dental Benefits

Vision Benefits

Flexible Paid Time Off

401(k)

Parental Leave

Life Insurance

Disability Coverage

Hybrid work schedule

Job summary

Kelly Services is hiring a Backend Engineer, LLM Applications to join a venture-backed startup building AI-powered customer experiences. You will design and develop services, APIs, and infrastructure that support large language model applications used by customers at scale.

This role focuses on production-grade backend systems, integrating LLM capabilities into customer-facing products, and shaping the technical foundation of a rapidly growing company.

Qualifications

• 4+ years of backend software engineering experience.
• Strong programming experience with Python, Go, Java, or similar languages.
• Experience building and maintaining APIs, microservices, and distributed systems.
• Hands-on experience deploying machine learning or LLM-powered applications into production environments.
• Experience designing scalable, reliable backend architectures.
• Understanding of cloud infrastructure and modern software development practices.
• Experience monitoring and supporting production applications.
• Strong communication and collaboration skills.

Responsibilities

• Design and develop backend services powering AI-enabled applications.
• Build APIs and microservices that support LLM workflows and customer experiences.
• Integrate large language models into scalable production systems.
• Develop tooling to evaluate, monitor, and improve AI application performance.
• Partner with product and engineering teams to design new features and capabilities.
• Improve system reliability, scalability, and observability.
• Troubleshoot issues across backend services, model integrations, and supporting infrastructure.
• Own solutions from architecture and development through deployment and optimization.
• Contribute to technical decisions that influence the future direction of the platform.

Skills

Backend engineering

Python

Go

Java

APIs & microservices

LLM in production

Distributed systems

Cloud infrastructure

Observability

Collaboration

Tools

Docker

Kubernetes

Job description

$127000 - $220000

Job DescriptionA venture-backed technology startup is building the next generation of AI-powered customer experiences and is looking for a Backend Engineer, LLM Applications to join its growing engineering team.

This role is ideal for a software engineer who enjoys building production systems at the intersection of backend engineering and generative AI. You will design and develop the services, APIs, and infrastructure that support large language model applications used by real customers at scale.

Unlike many AI-focused positions centered on experimentation or research, this role is highly focused on software engineering. You'll work on production-grade backend systems, integrate LLM capabilities into customer-facing products, and help shape the technical foundation of a rapidly growing startup.

Location: Newton, MA

Schedule: Hybrid, 3 days onsite per week

Salary: $127,000 - $220,000 Base Salary

Required Skills & Experience

• 4+ years of backend software engineering experience

• Strong programming experience with Python, Go, Java, or similar languages

• Experience building and maintaining APIs, microservices, and distributed systems

• Hands-on experience deploying machine learning or LLM-powered applications into production environments

• Experience designing scalable, reliable backend architectures

• Understanding of cloud infrastructure and modern software development practices

• Experience monitoring and supporting production applications

• Strong communication and collaboration skills

Desired Skills & Experience

• Experience working with Generative AI products or platforms

• Familiarity with LLM evaluation, observability, and monitoring practices

• Experience with retrieval-augmented generation (RAG), AI agents, or orchestration frameworks

• Knowledge of containerization and cloud-native technologies

• Experience in startup or high-growth environments

• Passion for building customer-facing AI products

What You Will Be Doing Daily Responsibilities

• Design and develop backend services powering AI-enabled applications

• Build APIs and microservices that support LLM workflows and customer experiences

• Integrate large language models into scalable production systems

• Develop tooling to evaluate, monitor, and improve AI application performance

• Partner with product and engineering teams to design new features and capabilities

• Improve system reliability, scalability, and observability

• Troubleshoot issues across backend services, model integrations, and supporting infrastructure

• Own solutions from architecture and development through deployment and optimization

• Contribute to technical decisions that influence the future direction of the platform

The Offer

• Competitive base salary up to $220,000

• Annual performance-based bonus opportunity

• Hybrid work environment with 3 days onsite per week in Newton, MA

• Opportunity to join a well-funded startup building cutting-edge AI products

• High-impact role with significant ownership and visibility

• Collaborative engineering culture with direct access to leadership

• Strong growth potential as the organization scales

You will receive the following benefits

• Medical Insurance

• Dental Benefits

• Vision Benefits

• Flexible Paid Time Off

• 401(k)

• Parental Leave

• Life Insurance

• Disability Coverage

Applicants must be currently authorized to work in the US on a full-time basis now and in the future.