Senior Software Engineer - LIMS Modernization

Role Description

CT LIMS is our most significant piece of custom-built enterprise software: a proprietary Laboratory Information Management System (LIMS) that runs production operations across multiple Onterris labs and carries a live, real-time Workday integration. It is a strategic asset despite its legacy codebase.

The team is doing the disciplined work to decide this system’s future: codebase archaeology, durable documentation and architecture readiness ahead of a modernization effort. The build starts fast. This is the engineer who helps make that build real.

You’ll bring modern engineering rigor (Spec-Driven, Test-First, AI-Augmented) to a system that has run for years on hard-won domain knowledge and a long-lived legacy codebase. You’ll reverse-engineer what exists, document it so any competent engineer can navigate it and help architect what comes next. One level down from owning the corporate transformation, you are the senior builder who turns specs and architecture decisions into working, tested software.

You’ll partner closely with the Staff Engineer, senior Labs developers, the cloud and landing-zone team, the platform architects and lab leadership. This is not pure archaeology and it is not a blank page. It is both at once.

The compensation range for this role is $200,000 - $210,000 USD, commensurate with experience, skills, and geographic location.

To thrive in this role, you'll be comfortable taking ownership of the following responsibilities:

• Build through Spec-Driven Development (SDD)
• Work “Blueprints Before Bricks”: the design is clarified in a Markdown specification before code is written.
• Author specifications and architecture-as-code in Markdown and Mermaid.js, committed to Git alongside the code.
• Help establish the templates and review habits that make spec-first development the default.
• Deliver test-first development (TDD)
• Build the automated test coverage that lets the team move fast with confidence.
• Hold the line on coverage standards, particularly for AI-generated code.
• Implement architectural guardrails that keep modular boundaries from eroding back into a monolith.
• Use AI as a force multiplier
• Use Cursor and Claude Code as primary instruments for codebase archaeology, documentation and prototyping.
• Contribute to the .cursorrules and prompt libraries that encode our architectural standards.
• Apply judgment about when AI accelerates (boilerplate, syntax, archaeology), when to collaborate (domain logic) and when to write manually (data integrity, edge cases).
• Reverse-engineer and document the legacy system
• Produce module-level documentation: purpose, inputs and outputs, dependencies, data models and known technical debt.
• Build data-flow diagrams for the sample lifecycle, Workday integration, billing and invoicing triggers, instrument interfaces and user authentication and authorization.
• Contribute to the integration inventory and technical-debt register, triaging components as Fix Now, Doc and Defer or Accept Risk.
• Contribute to architecture and cloud readiness
• Help shape CT LIMS placement within our Azure landing zone and environment tiers (production, non-production, sandbox).
• Contribute to high-availability and hybrid on-prem design, including the instrument-integration constraints that require a local network presence.
• Partner with the Staff Engineer, the cloud and landing-zone owner and the platform architects so the modernization aligns with adjacent Onterris platforms rather than duplicating them.
• Develop reference implementations and prototypes that de-risk the architecture choice while it is still being made.
• Help the team move from “ready to start” to “shipping” without a standing start if the modernization is approved.

Qualifications

• 7+ years of professional software engineering experience.
• Strong cloud-native engineering fundamentals (Azure preferred; AWS or GCP equivalent acceptable).
• Demonstrated practice with Spec-Driven and Test-Driven Development, clean architecture and domain-driven design.
• Hands-on experience with AI-assisted development tools (Cursor, Claude Code, GitHub Copilot or similar).
• Ability to read, reverse-engineer and reason about an unfamiliar or legacy codebase you did not write.
• Comfortable producing documentation and diagrams as code (Markdown, Mermaid.js) versioned in Git.
• Strong communication skills. You can explain the “why” to experienced engineers and partner effectively across teams.
• You respectfully challenge your peers, and welcome the opportunity when others challenge you.
• You are flexible, resilient and curious.
• You understand prior art but are compelled to iterate beyond it.

Requirements

• Experience reverse-engineering or maintaining systems written in Perl or another long-lived legacy language.
• Background in LIMS, scientific or other regulated and compliance-driven software (EPA reporting, chain-of-custody, lab accreditation).
• Experience with Oracle, and with evaluating database migrations (for example, toward PostgreSQL and or Snowflake).
• Familiarity with containerization (Podman or Docker) and hybrid on-prem and cloud deployment patterns.
• Exposure to enterprise integrations such as Workday.
• Familiarity with prompt engineering and AI workflow optimization.

Benefits

• Competitive salary range of $200,000 - $210,000 USD.
• Opportunity to work on impactful projects that protect the environment.
• Collaborative work environment with a focus on innovation.

Company Description

Onterris is a leading global environmental solutions company partnering with organizations to solve complex challenges where environmental pressures, regulatory expectations and operational risks intersect. Guided by our mission to advance the way of life without compromising the integrity of our environment, we believe environmental responsibility and human progress are fundamentally connected.

Our scientists, engineers, field teams and consultants apply systems thinking that unites science, data and practical expertise to deliver solutions that strengthen our clients’ resilience, mitigate risk and protect the air, water and soil that sustain communities, while uncovering responsible paths forward for planet and progress.

For more information, visit .

We are an equal opportunity employer and encourage applications from people of all backgrounds. We acknowledge that these experiences and perspectives help to enrich our teams and contribute to our ongoing success. We are committed to providing access and reasonable accommodation in our employment for all applicants.

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