Senior Back-End Software Engineer, Infra New

**About Us** ------------ Circle is building the world’s leading all\-in\-one platform for online communities. We make it possible for creators, coaches, educators, and businesses to bring together their audience with engaging discussions, live streams, events, chat, courses, and payments — all in one place, all under their own brand. We’re proud to be a fully remote company of around 200 (and growing!) team members from 30\+ countries around the world. We seek exceptional individuals around the world, set them up to do the best work of their lives, and in turn, create a meaningful impact in their own lives. We don't track hours, but we do manage for high expectations very closely. We collaborate across time zones, are highly async, and like to document a lot. Twice a year, we bring the whole company together in beautiful places around the world for our company offsites. So far, we’ve hosted offsites in Turkey, Portugal, Mexico, Thailand, Colombia, Italy, Ireland, and more, with still more to come! **About the role** ------------------ We're scaling quickly, and the foundation that supports our product needs to scale with it. We're hiring a Senior Back\-End Software Engineer to join our Infra team and take ownership of our Rails stack — keeping it modern, efficient, and built to last. You'll help shape internal tooling, reduce third\-party dependencies, and ensure our infrastructure is ready for the next stage of growth. **What you'll be doing** ------------------------ * Maintain and modernize our Rails stack, including dependency upgrades, performance optimization and security enhancement * Build internal tools, SDKs, and libraries to improve developer experience and infrastructure scalability * Partner with your front\-end counter\-parts and SREs to support observability, performance, and reliability initiatives * Identify opportunities to build in\-house systems that reduce reliance on costly third\-party services * Contribute to architectural decisions that improve the performance, security and cost\-efficiency of our platform **What you'll need to be successful** ------------------------------------- * Strong alignment with our values * You are proficient in English (spoken, written, and reading) at a CEFR Level C2 / ILR Level 5 * Deep expertise with **Ruby on Rails**, with an emphasis on infrastructure and architectural improvements * Solid experience working with **MySQL and/or Postgres** * A strong track record of improving performance, scalability, and system reliability * 5\+ years of experience in a back\-end engineering role, ideally focused on infrastructure or platform systems * Comfortable working autonomously in a fast\-paced, fully remote environment **Bonus points** ---------------- * You’ve helped scale an early\-stage product to 1M\+ monthly active users. * Experience with front\-end technologies (especially React) * You’ve built internal tooling or SDKs for use across engineering teams * Experience red