5 backend engineer jobs found

Overview Models write backend code that passes the happy-path test and falls over on everything else: the race condition under load, the N+1 that melts the database, the API contract that breaks every client the day you change it. Someone has to reason about the system, not just the snippet, and that someone is you. As a Backend Engineer you'll stress-test how models design services, data models, and APIs, expose where their reasoning breaks under real load, and write the answers a strong backend engineer would stand behind. What you’ll actually do Probe backend reasoning across service design, data modeling, and API contracts, and see where the model's design falls apart. Find the failures that matter : race conditions, N+1 queries, bad indexes, and breaking changes hiding in a clean-looking diff. Write the correct design when the model falls short, with the scaling and consistency trade-offs made explicit. Roles this fits Common backgrounds:...

Software Engineer – Ruby (AI Training) About The Role What if your Ruby expertise could directly influence how AI writes and understands backend code for developers around the world? We're looking for experienced Ruby Software Engineers to work on real-world software systems that power data-driven and AI-supported workflows — reviewing, building, and evaluating production-grade code that helps train the next generation of AI models. This is a fully remote, flexible contract role. Work asynchronously on your own schedule, take on as many hours as suits you, and make a tangible impact on how AI reasons about software engineering. Organization: Alignerr Type: Hourly Contract / Task-Based Location: Remote Commitment: 10–40 hours/week What You'll Do Develop and maintain backend services and APIs using Ruby and Ruby-based frameworks Review and analyze existing codebases for correctness, performance, and maintainability...

Systems Programmer — AI Data Pipelines About The Role What if your mastery of Rust could directly shape the infrastructure powering the world's most advanced AI systems? We're looking for a senior Rust engineer to design and build the high-performance data pipelines, annotation tooling, and evaluation systems that leading AI labs depend on to train and improve their models. This is a fully remote contract role working on real production systems — not toy projects. You'll be embedded alongside world-class data, research, and engineering teams, solving hard systems problems that have a direct impact on the trajectory of AI development. Organization: Alignerr Type: Hourly Contract Location: Remote Commitment: 20–40 hours/week What You'll Do Design, build, and optimize high-performance systems in Rust supporting large-scale AI data pipelines and evaluation workflows Develop full-stack tooling and backend services for data...

Backend Developer — AI Data Services About The Role What if your C# expertise could directly shape the infrastructure powering the next generation of AI? We're looking for a Senior C# Full-Stack Engineer to build and optimize the data pipelines, annotation tooling, and evaluation systems that leading AI labs depend on to train and improve their models. This is a fully remote contract role with meaningful, high-impact work — the kind where your code doesn't just sit in a backlog, it actively influences how AI systems learn and behave at scale. Organization: Alignerr Type: Hourly Contract Location: Remote Commitment: 20–40 hours/week What You'll Do Design, build, and optimize high-performance C# systems supporting AI data pipelines and evaluation workflows Develop full-stack tooling and backend services for large-scale data annotation, validation, and quality control Improve reliability, performance, and safety across...

Forward Deployed AI Engineer Location:  London, United Kingdom. Contract:  Freelance, with the possibility of future full-time employment. About the job: AI is forcing engineers to evolve like never before. The role is increasingly defined by deciding what a system should do and which specs and evals to write, then handing execution to agents and carefully checking what comes back. The best engineers we know still understand every layer underneath and are eager to spend more time thinking about how and why the solutions they build get used. That’s who we want to work with at Calibr, a startup founded by  Peter Wood  and  Marlene Leiss , and part of The Apprentify Group, one of the UK’s leading AI and tech training providers. We build tailored AI solutions for companies going through AI transformation, then help their teams build the skills to run, extend and own those systems themselves. As a Forward Deployed AI Engineer,...