Senior GenAI Developer

21Tech; Greater London; Hybrid; GBP 37,000 - 64,000; Full time

Job summary

A leading SaaS company based in the San Francisco Bay Area is looking for a Senior GenAI Developer to work on full-stack GenAI applications. This role involves developing end-to-end features, integrating ML models, and creating user interfaces to enhance business planning workflows. Applicants should have substantial software engineering experience and expertise in AI/ML technologies, particularly in Python and front-end development with React. This position offers the potential for remote work, providing a great opportunity to shape transformative AI capabilities.

Qualifications

• 4+ years of software engineering experience, with 2+ years focused on ML/AI systems.
• Strong programming skills in Python, with ML frameworks experience.
• Experience in deploying LLM-powered applications in production.

Responsibilities

• Develop end-to-end GenAI features, including backend API services.
• Integrate and optimize LLMs for business planning use cases.
• Build conversational interfaces and agentic workflows.

Skills

Software engineering

Machine Learning (ML)

Python

React

TypeScript

RESTful API design

ML frameworks (PyTorch, TensorFlow)

Prompt engineering

Containerization (Docker)

Kubernetes

Education

Bachelor's degree in Computer Science or related field

Tools

Docker

Kubernetes

Job description

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Senior GenAI Developer
Location: On-site in London; open to remote work from Romania or Poland
6-Month Contract | $82.07/hr USD

Our client, a leading SaaS company headquartered in the San Francisco Bay Area, is seeking a Senior GenAI Developer who can work across the full stack of GenAI applications-from model integration and prompt engineering to building intuitive user interfaces. You'll build production-ready AI features that empower business users to leverage the power of GenAI within their planning workflows, requiring both deep ML knowledge and strong software engineering skills.

Key Responsibilities

• Develop end-to-end GenAI features, including backend API services, model integration, model monitoring, evaluations, and deployments.
• Integrate and optimize LLMs for specific use cases in business planning, including prompt engineering and RAG implementations.
• Build conversational interfaces and agentic workflows that make complex planning tasks accessible through natural language.
• Implement evaluation frameworks to measure and improve GenAI feature quality, including accuracy, latency, and user satisfaction metrics.
• Design and develop APIs that expose AI capabilities to Client's platform and third-party integrations.
• Optimize model inference pipelines for performance, cost, and scalability in production environments.
• Implement monitoring, logging, and observability for GenAI systems to track usage, errors, and model behavior.
• Collaborate with data scientists to productionize ML models and forecasting algorithms.
• Write comprehensive tests, including unit tests, integration tests, and prompt regression suites.
• Participate in code reviews, technical design discussions, and knowledge-sharing sessions.
• Stay current with GenAI research and tools, evaluating new models and techniques for potential adoption.

Required Qualifications

• 4+ years of software engineering experience, with 2+ years focused on ML/AI systems.
• Strong programming skills in Python, including experience with ML frameworks (PyTorch, TensorFlow, Transformers).
• Experience building and deploying LLM-powered applications in production.
• Proficiency in front-end development with React, TypeScript, and modern web technologies.
• Understanding of RESTful API design, microservices architecture, and cloud infrastructure.
• Experience with prompt engineering and RAG systems.
• Strong foundation in ML fundamentals, including NLP, time-series analysis, or recommender systems.
• Familiarity with containerization (Docker), orchestration (Kubernetes), and CI/CD pipelines.
• Excellent problem-solving skills and attention to detail.
• Bachelor's degree in Computer Science, Machine Learning, or a related field.

Preferred Qualifications

• Experience with GenAI frameworks (LangChain, LlamaIndex, Haystack, or similar).
• Knowledge of vector databases (Pinecone, Weaviate, Qdrant) and embedding models.
• Experience with model serving frameworks (vLLM, TensorRT, Ray).
• Background in forecasting, planning, or analytics applications.
• Familiarity with Client or similar enterprise planning platforms.
• Experience with A/B testing and experimentation frameworks for AI features.
• Contributions to open-source ML projects or research publications.
• Experience with model observability tools (LangSmith, W&B, MLflow).

What Makes This Role Exciting

• Lead a greenfield team building transformative AI capabilities from the ground up.
• Work on cutting-edge conversational and agentic AI technologies.
• Build user-facing AI features that directly impact how businesses plan and make decisions.
• Experiment with the latest GenAI models and techniques.
• Collaborate with talented engineers, data scientists, and product designers.
• Solve unique challenges at the intersection of AI and enterprise software.
• Grow your skills in both ML engineering and full-stack development.