[Hiring] Staff Software Engineer, Backend @Kantiv (formerly Joist AI)

Role Description

We are looking for a Principal Backend Engineer / Architect to lead the technical direction of our core backend systems and serve as a cornerstone for our engineering culture. Your goal is to act as a force multiplier—training, mentoring, and guiding our developers to elevate their skills while ensuring our platform remains resilient, performant, and ready to scale alongside our rapidly growing AI capabilities.

What you’ll do

• System Architecture: Design, build, and evolve scalable, resilient, and high-performing backend services and APIs that power our AI-driven platform.
• Technical Leadership & Mentorship: Act as an expert guide for the engineering team. Train and upskill developers through architectural whiteboarding, pair programming, and thoughtful, constructive code reviews.
• Hands-on Engineering: Lead by example by tackling the most complex technical challenges, writing clean, maintainable code, and setting the quality standard for the rest of the team.
• Engineering Excellence: Define and enforce organization-wide best practices for system design, database schemas, automated testing, and observability to ensure our systems are robust and production-ready.
• Cross-Functional Alignment: Partner closely with Product, Platform, and AI engineering teams to ensure architectural alignment, seamlessly bridging traditional web backends with cutting-edge machine learning workloads.

Qualifications

• 8+ years of experience in backend software engineering, with a proven track record of architectural leadership, system design, and technical team leadership.
• Backend & API Mastery: Deep expertise in designing distributed systems, modern APIs (REST, GraphQL), microservices or modular monoliths, and complex data models.
• Polyglot Proficiency: Strong programming skills in modern backend languages (such as Python, Go, or similar) with the architectural wisdom to choose the right tool and design pattern for the job.
• Mentorship Mindset: Demonstrated experience leading, training, and leveling up mid-level and junior engineers.
• Cloud & Infrastructure Fluency: Solid understanding of public cloud environments, containerization, and how to architect cost-effective systems that leverage cloud-native services.
• Database Expertise: Strong grasp of modern data storage and processing, including relational databases, caching layers, and asynchronous messaging/event queues.

Requirements

• Proven experience navigating the technical and organizational challenges of scaling a high-growth SaaS platform from early traction to enterprise scale.
• Experience architecting systems that seamlessly integrate and serve ML models, LLMs, or other computationally heavy, data-intensive workloads.
• Deep knowledge of event-driven architectures, distributed tracing, and complex asynchronous processing patterns.

Attributes

• Exceptional problem-solving skills.
• A pragmatic approach to technical debt.
• High emotional intelligence.
• Excellent written and verbal communication.

Education

• Bachelor's degree in Computer Science, Engineering, or a related field (or equivalent practical experience).

What to expect

We conduct a rigorous interview process based on integrity, talent, and drive. The entire interview process typically takes two weeks. Here's what to expect:

• A 30 minute Zoom meeting to talk about Kantiv, your background, and answer any questions about the role.
• 45-minute Python proficiency / agentic coding proficiency test. 2 problems. 1 to be coded by hand. Other using Gen AI.
• 60 min project, deep dive into the work they have done. A short presentation followed by a Q&A.
• 45 min interview on Gen AI / LLM fundamentals.
• 30 min culture fit.