Senior Software Engineer – System Modernization

Overview:

One Identity's OneLogin team is seeking Senior Software Engineers who operate with high ownership, strong technical judgment, and a bias for action. These roles are designed for engineers who identify and solve problems proactively - not just execute assigned work.

Senior Engineers at OneLogin are expected to operate as T-shaped engineers: deep in a primary domain while remaining capable across the stack (backend, APIs, cloud, and operations). You will play a key role in maintaining product velocity, improving system reliability, and reducing operational burden.

This is a hands-on role that includes on-call responsibilities and requires a strong commitment to modern engineering practices, including AI-augmented development. We are looking for engineers who take full ownership - design, build, test, deploy, and operate - rather than handing work off between silos.

In this role, you will execute and evolve an incremental modernization strategy (e.g., strangler fig), safely transitioning legacy systems into scalable services while maintaining reliability and system continuity.

Responsibilities:

Execute and evolve an incremental modernization strategy, safely transitioning legacy systems into well-bounded services while maintaining reliability and continuity

Decompose monolithic systems incrementally using patterns such as strangler fig

Manage coexistence between legacy and modern systems during transition

Design clear service boundaries, contracts, and data ownership models

Ensure backward compatibility and safe evolution of APIs and data during migration

Improve performance, scalability, and maintainability as part of modernization efforts

Identify and prioritize high-impact areas for migration based on risk and value

Ideal Experience:

Hands-on experience incrementally modernizing monolithic systems in production environments

Experience with migration patterns such as strangler fig, parallel run, or phased rollouts

Strong understanding of system decomposition, including service boundaries and data ownership

Experience maintaining backward compatibility and managing API/data contracts during system evolution

Experience working with legacy systems and evolving them under real-world constraints

Experience debugging and validating behavior across both legacy and newly extracted services

Ability to balance migration velocity with system stability and risk

Familiarity with observability practices to validate system behavior during migrations

Experience using AI tools to analyze legacy systems, understand behavior, or accelerate refactoring and migration efforts

Qualifications:

Software Development

4+ years of professional software engineering experience with ownership of production systems and operational improvements

Strong backend development experience (Ruby, Node.js, or similar)

Solid understanding of REST APIs, service contracts, distributed systems, and common software design patterns

Experience working across backend systems, APIs, and production environments

Quality & Testing

Hands-on experience with automated testing across unit, integration, and API layers

Strong ownership of code quality, including testing, debugging, and validation

AWS & Cloud-Native Experience

Experience building and operating cloud-native services in AWS

Familiarity with CI/CD practices and modern deployment workflows

Observability & Production Operations

Experience using observability tools (e.g. Datadog or equivalent) to monitor, troubleshoot, and resolve production issues

Familiarity with incident response and continuous reliability improvements

On-Call & Incident Response

Willingness to participate in a 24/7 on-call rotation and support production issue resolution

AI-Augmented Engineering

Experience with or strong interest in AI-assisted development tools (e.g. GitHub Copilot, ChatGPT, Cursor) and the ability to effectively evaluate AI-generated solutions

Company Description

One Identity enables organizations of all sizes to better secure, manage, monitor, protect, and analyze information and infrastructure to help fuel innovation and drive their businesses forward. With team members around the globe, we intend to continue to grow revenues and add value to customers.

When you join our team, you will have the opportunity to build and develop products at a scale few others can provide. Our product portfolio serves a large base of customers and we are addressing the strategic imperatives for enterprise businesses. Working with some of the most talented employees the industry has to offer, we provide enhanced career opportunities for team members to learn and grow in a rapidly changing environment.

Come join us. For more information, visit us on the web at One Identity Careers | Explore Opportunities with the OI Team

Job seekers should be aware of fraudulent job offers from online scammers and only apply to roles listed on quest.com/careers using our applicant system. Note: We do not use text messaging or third-party messaging apps like Telegram to communicate with applicants, so please exercise caution if you are approached in this way and only interact with people claiming to be Quest employees if they have an email address ending in @quest.com or @oneidentity.com