Senior Back-end Developer

About Lemon.io Lemon.io is a profitable, growing talent marketplace that connects vetted senior engineers with companies that need them. We’ve been in business for 10 years, have 60 people across Ukraine, Europe, Canada, and the US, and process over $16M in annual GMV. We compress the traditional 2–5 week hiring timeline down to 24–48 hours through a curated, pre-vetted supply of developers. Hiring is still broken. Recruiters spend weeks building candidate pipelines on traditional platforms, burning energy on unqualified leads. We’re building the product that changes that. Giving recruiters qualified, vetted candidates within 24 hours without the grind. This is a pivotal moment: we’re transitioning from a services-driven marketplace to a technology-driven platform. We need an engineering leader who can drive that transformation. The Role You will own engineering at Lemon.io . You’ll lead a growing team of engineers, make critical architecture and prioritization decisions, and be directly accountable for the speed and quality of what we ship. This is not a management-layer role. You’ll be hands-on, deeply involved in product decisions, and working side by side with the founder. What You’ll Do: Own the technical roadmap and make sure every engineering effort maps directly to business impact. No features for features’ sake. Lead and grow an engineering team that ships fast, iterates constantly, and treats complexity as a cost. Tackle the hard, multi-layered problem: automated vetting, intelligent matching at scale, demand-side bottlenecks. And figure out where the real leverage is. Make hard prioritization calls. Decide what we build, what we skip, and what we kill. Work directly with the founder and product team to define what success looks like before writing a single line of code. Build the engineering culture: high ownership, high speed, low bureaucracy. Who You Are: Product-minded, business-first Obsessed with simplicity First principles thinker Fast. Bias toward…

Veröffentlicht 26 Oct 2026

We're looking for experienced software engineers to build AI coding tasks from a codebase they know well. US$1,000 per task, and you can do as many tasks as you want. You turn a real change from a repository you know into a task that today's best AI coding models struggle with: hard for the models, but fair for a skilled engineer. Your tasks are used to measure and train AI coding models. Remote, any location. US$1,000 per task that passes review. Minimum of one task a week, about 10 hours a week. How it works Apply. Complete a short screener interview and upload your resume. Propose. Once you're selected, pick a change from a repository you know and submit a short proposal. We approve it or suggest a better candidate. Build. In our platform, set up the repository as it was before the change, then write the brief, the correct solution and the grading checks. Stress-test. Try lazy, incorrect and shortcut solutions and make sure your checks catch them. Model testing. Run your task against leading AI models until strong models often fail but a skilled engineer can clearly solve it. Review. A reviewer checks your task and you revise it. Most tasks take more than one round. Next task. Once your task is accepted, start another. Requirements 2+ years of professional software engineering Code merged into a public open-source repository, ideally one you know well. A private codebase you own may also qualify (not employer or client code) Strong in at least one of Python, TypeScript, Go, Rust, Java or C++ Solid with Docker, Linux, Git and automated testing Regular use of an AI coding tool Experience writing tests, rubrics or evaluation criteria, ideally for AI models You can explain a change clearly and concisely, in your own words At least 10 hours a week, starting now A secure personal or work computer (no public or shared machines) Nice to have Deep expertise in one area, such as databases, compilers, distributed systems, security or infrastructure Experience building agen…

$1000 per task

Veröffentlicht 17 Oct 2026

Who Should Apply We are looking for developers from all technical backgrounds and language specializations. If you write clean code and understand software design, you are a fit: Software Engineers & Computer Scientists specializing in algorithms, data structures, or system design. Full-Stack & Web Developers working with modern front-end or back-end frameworks (JavaScript, TypeScript, React, Node.js, Python, PHP, Ruby, etc.). Backend & Systems Developers experienced in languages such as C++, Java, Go, Rust, or Python. DevOps & Database Engineers familiar with API design, SQL/NoSQL databases, or scripting. Role & Responsibilities As an AI Code Trainer , you will evaluate model-generated code, author reference solutions, and stress-test AI reasoning across various engineering domains. Code Auditing & Quality Analysis: Critique AI-generated solutions for logic, performance, security vulnerabilities, syntax, and coding best practices. Gold-Standard Solutions: Write clean, production-grade reference code and clear technical explanations for complex programming prompts. Test Design: Build unit tests and edge-case scenarios to evaluate model accuracy and expose edge-case failures. Technical Feedback: Write structured explanations detailing why an AI solution succeeds, fails, or produces bugs. Requirements Software Engineering Proficiency: Strong core fundamentals in at least one major programming language or web stack (e.g., Python, JavaScript/TypeScript, Java, C++, Go, C#, Rust, PHP). Debugging & Code Review: Ability to quickly analyze third-party code, catch subtle logical errors, and evaluate efficiency. Technical Communication: Clear written English to explain technical concepts and code review rationales effectively. Eligible Locations: Resident of USA, UK, Canada, Australia, New Zealand, India, Pakistan, or Philippines . Why Join Us? $50–$125/hr commensurate with your technical domain expertise and task complexity. Weekly Guaranteed Payouts directly to your choice …

$45-$120/Hour

Veröffentlicht 5 Oct 2026