Engineer III Full Stack Backend Mostly

Engineer III, Full-stack - Mostly Backend

Location:

Columbus

Reports To:

EVP Engineering

Onsetto is building a white label, AI powered platform that simplifies and accelerates commercial bank account switching. We help financial institutions win more business, grow deposits, and establish primacy by automating complex AR, AP, and payroll transitions with bank grade reliability.

Because we automate mission critical financial workflows for banks, our backend systems must be secure, scalable, and architected for long term growth.

We are seeking a senior backend engineer to take ownership of core platform services, support the Banker Portal, maintain and improve our LLM driven workflows, and reduce dependency on senior leadership for day to day technical execution.

This role requires strong architectural judgment, hands on coding ability, and the ability to build production grade systems that support financial institutions.

• Design, build, and maintain scalable backend systems using Python and Django
• Own core services, APIs, and SDK development
• Lead database schema design and performance optimization
• Improve system reliability and long term maintainability

• Build and maintain backend services supporting banker facing workflows
• Ensure secure handling of financial and customer data
• Collaborate with frontend engineers on API contracts and system integration

• Maintain and improve LLM driven workflows and automation pipelines
• Optimize data processing and prompt orchestration logic
• Ensure AI powered features are reliable, auditable, and production ready

• Identify and resolve bottlenecks in database and service layers
• Improve background job processing and task orchestration
• Design systems that scale with growing bank adoption

• Take ownership of complex technical initiatives
• Reduce workload burden on senior engineers and leadership
• Mentor junior engineers where appropriate
• Contribute to architectural decision making and code review standards

• 5 plus years of backend engineering experience
• Strong proficiency in Python and Django
• Experience designing and building RESTful APIs
• Solid database design experience with relational databases
• Experience building production systems that handle sensitive data
• Experience and ability to program with React / Typescript as needed

• Experience integrating AI or LLM based systems into production applications
• Familiarity with React based frontend integration
• Experience in financial services or regulated environments
• Exposure to AWS infrastructure and cloud architecture

• Core backend systems are stable, scalable, and well documented
• Reduced technical dependency on founders for implementation details
• Clean API design supporting banker workflows
• Improved performance and reliability across services

You will play a critical role in building the technical backbone of a banking infrastructure platform. Your work will directly support financial institutions in growing deposits and strengthening client relationships, while shaping the long-term architecture of the company.