Top Tech Jobs & Startup Jobs in Denver & Boulder, CO

Research and prototype transformer-based and graph-based foundation models using customer, transaction, and merchant data. The intern will design and train models, run rigorous experiments, evaluate results, and develop working prototypes. Responsibilities include collaborating with Product, Engineering, Analytics, and Applied Science teams to improve customer experience, operational efficiency, and business outcomes.

Software Engineering Interns will collaborate with engineering and cross-functional teams on real-world projects, contribute to key engineering initiatives, build technical and professional skills, and present their work at the end of the program. Interns receive mentorship, workshops, and career development support while working full-time in the New York City office for eight weeks.

Lead a hands-on site reliability engineering team while writing production code and building automation, observability, incident-response tooling, and safe deployment practices. Own service reliability standards, alerting, dashboards, runbooks, rollback safety, incident command, remediation, and sustainable on-call coverage. Partner with engineering teams to improve reliability across high-availability financial services supporting millions of customers.

Builds production-ready design and interface components in code, bridging design and engineering across React Native, React, and mobile and web platforms. Uses AI coding tools such as Cursor, Claude Code, and v0 at high production velocity. Defines design-to-code workflows, design tokens, component architecture, and improved handoff practices while collaborating closely with designers and engineers in a fast-moving environment.

Leads treasury analytics and strategy by building cash forecasting, balance sheet, capital, ALM, liquidity, interest rate, FX risk, stress testing, and scenario models. Develops treasury data infrastructure, reporting, controls, reconciliations, and capital adequacy processes. Partners with finance, accounting, FP&A, operations, legal, risk, and compliance teams to improve cash utilization, funding strategies, regulatory compliance, and long-term capital efficiency. Incorporates AI and scalable data tools into treasury operations.

As a Forward Deployed Engineer, you will develop AI agents and automation workflows, collaborate with teams, and ensure secure, reliable solutions integrating with various systems.

Designs and owns shared test automation frameworks and scalable test execution infrastructure across web, mobile, and backend services. Builds tooling for test environments, test data, parallel execution, flaky-test detection, and infrastructure monitoring. Partners with engineering teams to improve test coverage and quality practices, reduces feedback-loop friction, and documents testing best practices. The role requires strong automation architecture, cloud-native infrastructure, cross-stack testing, and collaborative influence.

Build and maintain resilient backend services and APIs for fraud detection, identity verification, and transaction monitoring. Integrate third-party risk/compliance platforms, partner with product and engineering teams, contribute to architecture decisions, and produce documentation to ensure secure, reliable systems at scale.

Design and productionize machine learning, deep learning, LLM, personalization, recommendation, search, and retrieval systems. Collaborate with product, engineering, and analytics teams to deploy AI solutions that improve customer experiences, business growth, and operational efficiency. The role requires driving projects from ideation through deployment and delivering measurable business impact in a fast-moving fintech environment.

Develops partnership-led product expansion strategy, evaluates build-versus-partner opportunities, conducts market and partner analysis, presents recommendations to leadership, represents OnePay externally, and leads partner selection and commercial contract negotiations through execution.