Lead Ruby Developer - Onsite (Chicago, IL)

Job Title: Lead Ruby Developer Work Location: Chicago, IL Key Responsibilities &Required Technical Expertise: Strong Expertise with Ruby: Minimum 12 years of experience on Ruby Deep knowledge of Ruby MRI internals (GIL, memory model, object allocation) Ruby MRI garbage collector (mark & sweep, generational GC) Strong experience with Rails internals (ActiveRecord, Arel, middleware stack) Ability to optimize slow queries, N+1 issues, and memory leaks Experience with multi-threaded / concurre

Job Description : Strong Expertise with Ruby: Minimum 12 years of experience on Ruby Deep knowledge of Ruby MRI internals (GIL, memory model, object allocation) Ruby MRI garbage collector (mark & sweep, generational GC) Strong experience with Rails internals (ActiveRecord, Arel, middleware stack) Ability to optimize slow queries, N+1 issues, and memory leaks Experience with multi-threaded / concurrent Ruby (Puma, Sidekiq tuning) Ruby VM instruction set (YARV bytecode basics) Concurrent Ruby gem

A well-established technology organization is seeking a Ruby-focused contractor to support a time-sensitive modernization initiative. This role centers on upgrading a legacy USPS shipping integration to the latest REST-based USPS API v4. The engagement is fully remote, contract-based, and designed for an engineer who can work independently and deliver within a clearly defined scope. This project is ideal for a seasoned engineer who enjoys short-term, high-impact contract work without long-term o

We are seeking a skilled Software Engineer with strong Ruby on Rails experience to help design, build, and maintain secure, scalable applications that support critical healthcare services. This role will work closely with product, data, and clinical stakeholders to develop technology that improves patient outcomes, operational efficiency, and care delivery experiences. You'll contribute across the full development lifecycle - from architecture and design through implementation, testing, deployme