Senior Backend / AI Applications Engineer

Mobi.AI • Somerville, MA

2d • Hybrid

About The Position

Mobi.AI partners with leading travel brands to create AI experiences for travel discovery and booking. The Senior Backend / AI Applications Engineer will join a collaborative, fast-paced team to design and build reliable backend services and AI-driven applications powering Mobi’s travel AI products. This hands-on role has end-to-end ownership of production services, from clarifying customer needs and making architecture trade-offs through implementation, deployment, monitoring, and ongoing reliability. The engineer will work closely with product, design, and engineering colleagues to build APIs, integrations, and agent workflows for customers and travelers.

The role requires strong proficiency in AI-assisted software development. The engineer will use AI coding assistants and agents throughout the software development lifecycle, thoughtfully guide and evaluate their output, and remain accountable for the resulting design, code, tests, and production behavior. Mobi seeks someone curious about new AI-enabled ways of working and willing to share them.

Requirements

• Bachelor’s degree in Computer Science, Engineering, or a related field, or equivalent practical experience.
• Strong Python skills and a track record of independently owning production backend services, explaining architecture trade-offs, and turning ambiguous requirements into reliable, maintainable systems.
• Experience writing automated Python tests (such as pytest), API and integration tests, and browser-based end-to-end tests where the product requires them.
• Proficiency with backend APIs and RESTful services.
• Experience with AWS compute and storage services, such as Lambda and DynamoDB.
• Demonstrated ability to use AI coding assistants and agents to build and improve software, evidenced by professional work or substantial projects.
• Ability to direct AI tools through changes across multiple files in an existing codebase, including implementation, test generation, debugging, and refactoring.
• Strong judgment in evaluating AI-generated solutions: able to explain code, verify its behavior, identify errors, and recognize when independent investigation or a different approach is needed.
• Strong problem-solving skills and a collaborative mindset.
• Understanding of MCP and agent frameworks.

Responsibilities

• Develop, test, and maintain MCP services and agent applications that connect Mobi’s travel AI products to customer and partner systems.
• Build and operate Python APIs, integrations, and AWS infrastructure with clear contracts, authentication, retries, idempotency, observability, and actionable error handling.
• Collaborate with cross-functional teams to define, design, and ship new features.
• Use AI coding assistants and agents throughout the development lifecycle to accelerate delivery while maintaining standards for correctness, accessibility, performance, and maintainability.
• Optimize applications for speed, scalability, and performance.
• Review code to troubleshoot, debug, and resolve issues; implement best practices for code quality, testing, and maintainability.
• Build automated unit, integration, contract, and end-to-end tests to verify software correctness and service reliability.
• Develop scenario-based agent evaluations for tool selection, grounding, task completion, failure handling, and regressions, with explicit expected outcomes and checks for nondeterministic behavior.
• Stay current with trends, tools, and emerging technologies in computer science and artificial intelligence.

Benefits

• Competitive base salary and annual bonus.
• Comprehensive medical, dental, and vision insurance for the employee and family, mostly covered by the company.
• Company-paid disability and life insurance.
• Optional pet insurance and identity theft protection.
• Paid parental leave for all types of parents and families.
• Equity ownership in the company.
• 401(k) plan.
• Unlimited paid time off, plus a $1,000 bonus for taking five consecutive days off.
• Flexibility to work anywhere in the world for one month a year.
• Tuition reimbursement.
• Cell phone and transportation reimbursement.
• Daily lunch from local restaurants.
• Office amenities including a full kitchen, massage chairs, and live plants.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior