Senior Python Engineer / Lead Developer (Agentic/llm systems)
Position Overview
We're seeking an exceptional Senior Python Engineer to take technical leadership of a complex, production-grade codebase. This role involves architecting and developing sophisticated systems that combine AI/LLM integration, code analysis, and security tooling. You'll be responsible for architectural decisions, feature development, team mentorship, and maintaining the highest standards of code quality.
Location : Remote
Experience Level: Senior (5+ years)
Commitment : Full-time
Core Responsibilities
- Technical Leadership
- Make critical decisions about system architecture, design patterns, and technology choices
- Establish and enforce coding standards, review practices, and quality benchmarks
- Define and prioritize technical initiatives aligned with product goals
- Lead architectural discussions and drive consensus on complex technical decisions
- Ensure system performance and scalability for production workloads
Feature Development
- Design and implement core system components using modular, extensible architectures
- Build and maintain integrations with external APIs and services (LLM providers, databases, etc.)
- Develop analysis engines and processing pipelines for complex data workflows
- Implement testing frameworks and validation systems
- Optimize critical code paths and system bottlenecks
Team Collaboration & Mentorship
- Review pull requests and provide constructive technical feedback
- Mentor junior and mid-level engineers in best practices and technical growth
- Maintain comprehensive technical documentation and architectural diagrams
- Conduct technical presentations and knowledge transfer sessions
- Collaborate across functions with stakeholders and team members
Technical Innovation
- Stay current with advances in Python ecosystem, AI/ML technologies, and relevant domains
- Evaluate and integrate new libraries, frameworks, and tools
- Research and prototype solutions to complex technical challenges
- Contribute to technical strategy and long-term planning
Required Technical Skills
- Python Expertise (Required)
- 5+ years of professional Python development with advanced proficiency in:
- Async/await patterns and concurrent programming
- Type hints and Pydantic for data validation
- Decorators, metaclasses, and advanced language features
- Modern package management (uv, pip, poetry)
- Testing frameworks (pytest, mocks, fixtures, test-driven development)
- Software Architecture: Experience designing modular, plugin-based systems with clean abstractions
- API Design: Creating intuitive interfaces and maintainable code structures
- Performance: Profiling, optimization, and handling large-scale data processing
- Version Control: Git workflows, code review practices, and collaborative development
- LLM & AI Integration (Preferred)
- LLM APIs: Hands-on experience with OpenAI, Anthropic, or similar providers including:
- Function/tool calling and structured outputs
- Prompt engineering and optimization
- Session management and conversation state
- Token tracking and cost optimization
- RAG Systems (Nice to have): Experience with vector databases (ChromaDB, Pinecone, Weaviate), embeddings, semantic search, LlamaIndex or LangChain
- AI/ML Concepts: Understanding of temperature, sampling, context windows, and model behavior
- Code Analysis & Parsing
- AST & Static Analysis: Experience with abstract syntax trees, code parsing, and program analysis
- Pattern Matching: Regex, semantic search, and code query techniques
- Control Flow: Understanding of call graphs, data flow, and execution path analysis
- Smart Contracts (Preferred) - Solidity and/or Rust: Ability to read and understand smart contract code
- Blockchain Fundamentals: Knowledge of EVM, transactions, gas mechanics, and contract execution patterns
- Security Awareness: Familiarity with common vulnerability patterns (reentrancy, access control, etc.)
- Tooling: Experience with Foundry, Hardhat, Anchor, or similar development frameworks
Additional Skills
- CLI Development: Building command-line tools (Typer, Click, argparse)
- Web Frameworks (Nice to have): Flask, FastAPI for APIs and web interfaces
- DevOps Basics: CI/CD, Docker, GitHub Actions
- Data Storage: Working with JSON, databases, and caching systems
- Software Development Best Practices
- Clean Code: SOLID principles, design patterns, and writing maintainable, extensible code
- Documentation: Clear technical documentation, architecture decision records (ADRs), and API documentation
- Testing Strategy: Comprehensive testing approaches including unit, integration, and end-to-end tests
- Code Review: Effective review practices with constructive, actionable feedback
- Agile Development: Experience with iterative development and continuous improvement
- Security Mindset: Awareness of common security vulnerabilities and defensive programming practices
Preferred Qualifications
- 5+ years of professional Python development
- 2+ years in a technical leadership or senior engineering role
- Experience building AI/LLM-powered applications in production
- Background in security, static analysis, or developer tools
- Experience with smart contracts (Solidity, Rust) or blockchain technologies (strong plus)
- Active open-source contributions (strong plus)
Technical Accomplishments
- Built and deployed production systems with complex workflows
- Designed and implemented modular, plugin-based architectures
- Experience with large-scale data processing or analysis systems
- Technical writing, blog posts, or conference presentations (plus)
- Company
- Cyfrin
- Location
- United Kingdom, UK
- Posted
- Company
- Cyfrin
- Location
- United Kingdom, UK
- Posted