Senior Software Engineer - LIMS Modernization

LE002 Onterris Payroll, LLC; Little Rock (AR); On-site; USD 200,000 - 210,000; Full time

Job summary

Onterris is seeking a senior software engineer to modernize CTLIMS, our Laboratory Information Management System, connecting to Workday in real time. You will lead spec-first development, write Markdown specs and architecture-as-code, and advance test-driven delivery across cloud and hybrid environments.

You will mentor teams, document legacy modules, and build data-flow diagrams while shaping the Azure landing zone.

Qualifications

• 7+ years of professional software engineering experience.
• Strong cloud-native engineering fundamentals (Azure preferred; AWS or GCP 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, ClaudeCode, GitHubCopilot, or similar).
• Ability to read, reverse-engineer, and reason about an unfamiliar or legacy codebase.
• Comfortable producing documentation and diagrams as code (Markdown, Mermaid.js) versioned in Git.
• Strong communication skills; can explain the “why” to experienced engineers and partner effectively across teams.

Responsibilities

• Build through Spec-Driven Development; author Markdown specifications and architecture-as-code with Mermaid.js, commit to Git.
• Establish spec-first development templates and review habits.
• Deliver test-first development (TDD); build automated test coverage to enable fast, confident releases.
• Maintain coverage standards, especially for AI-generated code.
• Implement architectural guardrails to keep modular boundaries and prevent monolith erosion.
• Use AI tools (Cursor, ClaudeCode) for codebase archaeology, documentation and prototyping; contribute to .cursorrules and prompt libraries.
• Reverse-engineer and document legacy system modules: purpose, inputs, outputs, dependencies, data models, and technical debt.
• Create data-flow diagrams for sample lifecycles, Workday integration, billing triggers, instrument interfaces, and authentication/authorization.
• Contribute to integration inventory and technical-debt register, triaging components as Fix Now, Doc, Defer, or Accept Risk.
• Shape CTLIMS placement within our Azure landing zone and environment tiers (production, non-production, sandbox); support high-availability and hybrid on-prem design.
• Work with Staff Engineer, cloud landing-zone owner, and platform architects to align modernization with existing Onterris platforms.
• Develop reference implementations and prototypes to de-risk architecture choices.
• Help the team move from “ready to start” to shipping without a standing start, assuming modernization is approved.

Skills

Cloud-native engineering

Spec-Driven Development

Test-Driven Development

AI-assisted development tools

Legacy system understanding

Documentation as code

Cross-team communication

Tools

Azure

Git

Mermaid.js

Podman

Docker

Workday integration

Job description

At Onterris, we build careers grounded in purpose, responsibility and real‑world impact. This role is focused on modernizing our proprietary Laboratory Information Management System (CTLIMS), a strategic asset that supports production operations across multiple labs and links to Workday in real time.

Compensation

$200,000–$210,000USD, commensurate with experience, skills, and geographic location.

Responsibilities

• Build through Spec‑Driven Development (SDD); author Markdown specifications and architecture‑as‑code with Mermaid.js, commit to Git.
• Establish spec‑first development templates and review habits.
• Deliver test‑first development (TDD); build automated test coverage to enable fast, confident releases.
• Maintain coverage standards, especially for AI‑generated code.
• Implement architectural guardrails to keep modular boundaries and prevent monolith erosion.
• Use AI tools (Cursor, ClaudeCode) for codebase archaeology, documentation and prototyping; contribute to .cursorrules and prompt libraries.
• Reverse‑engineer and document legacy system modules: purpose, inputs, outputs, dependencies, data models, and technical debt.
• Create data‑flow diagrams for sample lifecycles, Workday integration, billing triggers, instrument interfaces, and authentication/authorization.
• Contribute to integration inventory and technical‑debt register, triaging components as Fix Now, Doc, Defer, or Accept Risk.
• Shape CTLIMS placement within our Azure landing zone and environment tiers (production, non‑production, sandbox); support high‑availability and hybrid on‑prem design.
• Work with Staff Engineer, cloud landing‑zone owner, and platform architects to align modernization with existing Onterris platforms.
• Develop reference implementations and prototypes to de‑risk architecture choices.
• Help the team move from “ready to start” to shipping without a standing start, assuming modernization is approved.

Qualifications

• 7+ years of professional software engineering experience.
• Strong cloud‑native engineering fundamentals (Azure preferred; AWS or GCP 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, ClaudeCode, GitHubCopilot, or similar).
• Ability to read, reverse‑engineer, and reason about an unfamiliar or legacy codebase.
• Comfortable producing documentation and diagrams as code (Markdown, Mermaid.js) versioned in Git.
• Strong communication skills; can explain the “why” to experienced engineers and partner effectively across teams.
• Respectfully challenge peers and welcome challenges from others.
• Flexible, resilient, and curious; iterate beyond prior art.
• Preferred: Experience reverse‑engineering or maintaining systems written in Perl or another long‑lived legacy language.
• Preferred: Background in LIMS, scientific or regulated software (EPA reporting, chain‑of‑custody, lab accreditation).
• Preferred: Experience with Oracle, and evaluating database migrations (e.g., toward PostgreSQL or Snowflake).
• Preferred: Familiarity with containerization (Podman or Docker) and hybrid on‑prem/cloud deployment patterns.
• Preferred: Exposure to enterprise integrations such as Workday.
• Preferred: Familiarity with prompt engineering and AI workflow optimization.

EEO Statement

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. For U.S. residents, click here to learn more.