Senior Engineer, Legacy Systems Modernization

TrueML; Ciudad de México; On-site; MXN 600,000 - 1,000,000; Full time

Job summary

TrueML is seeking a senior software engineer to work on mature, business-critical systems and shape their evolution. You will design, build, and maintain internal tools within legacy platforms and contribute to architectural decisions.

You will mentor engineers, collaborate with stakeholders, and ensure reliability, performance, and maintainability across the codebase while moving legacy systems toward modern standards.

Qualifications

• 5+ years of professional software engineering experience building and shipping production software.
• Experience with software architecture, including designing systems and making sound technical trade-offs.
• Comfort working in and improving legacy codebases.
• Strong programming fundamentals and the ability to learn new languages and tools quickly.
• Experience with Scala and/or Python.
• Experience building services or APIs used by other engineers or internal teams.
• Strong communication skills and confidence working on high-visibility projects.

Responsibilities

• Design, build, and maintain internal tools and services, primarily within legacy systems.
• Contribute to architectural decisions, including how to incrementally modernize and improve existing platforms.
• Deliver on high-revenue projects where reliability, correctness, and performance are essential.
• Collaborate with stakeholders across engineering and the business to understand needs and communicate progress.
• Improve the maintainability, testing, and observability of existing codebases.
• Write clear technical documentation and share knowledge with the team.
• Participate in code reviews, mentor less-experienced engineers, and help raise the engineering bar.

Skills

Software architecture

Legacy codebases

Scala

Python

APIs/services

Communication

High-visibility projects

Tools

CI/CD pipelines

AWS/GCP

Containers

Job description

TrueML is seeking a senior software engineer to work on mature, business-critical systems and shape their evolution. You will design, build, and maintain internal tools within legacy platforms and contribute to architectural decisions.

You will mentor engineers, collaborate with stakeholders, and ensure reliability, performance, and maintainability across the codebase while moving legacy systems toward modern standards.