Senior Python Application Developer

Citi; New York (NY); On-site; USD 110,000 - 150,000; Full time

Job summary

Citi is seeking a Senior Python Application Developer to architect and deliver mission-critical enterprise applications. The ideal candidate has extensive experience in Python, application development, and systems architecture, focusing on innovation and technical leadership.

This role will involve mentoring engineering teams, ensuring robust execution of strategic initiatives, and overseeing the software development lifecycle. Strong expertise in scalable system design and proven leadership capabilities are essential.

Qualifications

• 8+ years of experience in application development and systems architecture.
• Expert in Python 3.x and experienced with asynchronous programming.
• Hands-on experience designing and securing APIs.

Responsibilities

• Architect and develop high-performance Python applications.
• Lead cross-functional engineering teams and enforce code quality standards.
• Mentor junior developers and contribute to the technical roadmap.

Skills

Python

Enterprise Application Development

SQL Optimization

AI/ML Frameworks

Agile Methodologies

Tools

Docker

Kubernetes

AWS

CI/CD Tools

Job description

Job Overview

Senior Python Application Developer We are seeking an exceptionally skilled and driven Lead Python Application Developer to architect, develop, and deliver mission‑critical enterprise applications within a high‑performance Python ecosystem. This role demands a seasoned technologist with a proven track record of technical leadership, deep expertise in scalable system design, and a passion for driving innovation through cutting‑edge Python development. The successful candidate will play a pivotal role in shaping our technical roadmap, mentoring engineering teams, and ensuring the robust, secure, and efficient execution of strategic initiatives.

Required Qualifications

I. Advanced Technical Leadership & Architectural Acumen

• 8+ years of progressive experience in application development and systems architecture, with a laser focus on Python‑centric solutions.
• Demonstrable expertise in end‑to‑end software development lifecycle (SDLC) leadership, from strategic planning and solution architecture to deployment and post‑production optimization.
• Proven capability to lead and inspire cross‑functional engineering teams, foster a culture of technical excellence, and enforce rigorous code quality standards through comprehensive code reviews and design critiques.
• Act as a Subject Matter Expert (SME) in advanced Python paradigms, including asynchronous programming (asyncio), concurrency, and parallel processing, alongside profound knowledge of modern frameworks such as FastAPI, Django REST Framework, and Flask.
• Mastery of enterprise‑grade software architecture patterns, including Microservices, Event‑Driven Architectures (Kafka, RabbitMQ), Domain‑Driven Design (DDD), and GraphQL.
• Deep understanding of Object‑Oriented Programming (OOP) and Functional Programming principles, applying them to construct highly modular, extensible, and maintainable codebases.

II. Core Technical Proficiency & Implementation Excellence

• Expert‑level proficiency in Python 3.x, with extensive experience in developing high‑throughput, low‑latency, and fault‑tolerant applications leveraging its comprehensive standard library and vibrant third‑party ecosystem.
• Comprehensive hands‑on experience with diverse database technologies, including advanced SQL optimization for relational databases (PostgreSQL, Oracle, SQL Server) and schema design for NoSQL solutions (MongoDB, Cassandra, Elasticsearch, Redis).
• Architectural and implementation expertise in designing, securing (OAuth2, JWT), and optimizing RESTful and gRPC APIs, focusing on idempotency, rate limiting, and robust error handling.
• Mandatory hands‑on experience with enterprise CI/CD pipelines (Jenkins, GitLab CI, GitHub Actions, Azure DevOps) to implement fully automated testing, build, and deployment strategies (GitOps principles).
• Extensive cloud platform experience (AWS, Azure, or GCP), encompassing infrastructure‑as‑code (Terraform, CloudFormation), serverless computing (AWS Lambda, Azure Functions), and a deep understanding of cloud‑native services.
• Proficient in containerization technologies (Docker) and advanced Kubernetes orchestration, including Helm, service meshes (Istio, Linkerd), and custom resource definitions (CRDs).
• Elite‑level troubleshooting, performance profiling, and optimization skills for distributed systems, leveraging tools like Prometheus, Grafana, Jaeger, and custom instrumentation.
• Advocate and implement advanced automated testing strategies (unit, integration, end‑to‑end, performance) using frameworks like Pytest, Hypothesis, and Selenium, embracing Test‑Driven Development (TDD) as a core practice.
• Robust understanding and practical application of secure coding principles, static/dynamic analysis tools, and best practices for mitigating common vulnerabilities (OWASP Top 10, data encryption, secrets management with Vault).
• Expertise in advanced Git workflows (Gitflow, Trunk‑Based Development), including sophisticated branching, merging strategies, and pull request automation.

III. Artificial Intelligence (AI) Integration & Development

• Demonstrated experience with AI/ML lifecycle, from data preprocessing and model training to deployment and monitoring, utilizing frameworks such as TensorFlow, PyTorch, Hugging Face, and scikit‑learn.
• Practical experience integrating and leveraging advanced AI development tools and platforms (GitHub Copilot, Devin, Windsurf, Antigravity) to enhance developer productivity and code quality.
• Hands‑on experience designing, developing, and deploying Agentic AI systems, including the creation of custom agents, defining specialized skills, and contributing to agentic frameworks for automating complex development and operational workflows.
• Strong understanding and practical application of Generative AI models (GPT, Gemini, Claude) for code generation, natural language processing (NLP) tasks, and intelligent automation within the software development pipeline.

IV. Methodology & Professional Skills

• Deep understanding and practical experience with Agile/Scrum/Kanban methodologies, fostering a collaborative, iterative, and results‑oriented development environment.
• Exceptional organizational skills, with the ability to dynamically re‑prioritize and meticulously manage multiple high‑stakes tasks in a fast‑paced, evolving technical landscape.
• Proven leadership in project management, including meticulous stakeholder communication, resource optimization, and cross‑functional team coordination.
• Superior written and verbal communication skills, capable of articulating complex technical concepts with clarity and precision to both technical and executive audiences.

Desirable Qualifications

• Polyglot Programming Proficiency: Experience with additional programming languages (Java, Go, Scala, Rust), particularly in the context of enterprise microservices or high‑performance computing.
• Big Data & Real‑time Analytics: Hands‑on experience with Big Data technologies (Apache Spark, Flink, Hadoop, Kafka Streams) and architecting real‑time data processing pipelines.
• Frontend Development Expertise: Proficiency in modern frontend frameworks (React.js, Angular, Vue.js) for full‑stack application delivery.
• Cloud & Industry Certifications: Relevant advanced cloud certifications (AWS Certified Solutions Architect – Professional, Azure Solutions Architect Expert, Google Cloud Professional Cloud Architect) or industry‑recognized certifications in specialized technical domains.
• Financial Domain Acumen: In‑depth understanding of financial services industry regulations, compliance standards, and specific domain knowledge relevant to capital markets, retail banking, or enterprise risk management.

EEO Statement

Citi is an equal opportunity employer, and qualified candidates will receive consideration without regard to their race, color, religion, sex, sexual orientation, gender identity, national origin, disability, status as a protected veteran, or any other characteristic protected by law. If you are a person with a disability and need a reasonable accommodation to use our search tools and/or apply for a career opportunity, review Citi’s Accessibility at Citi. View Citi’s EEO Policy Statement and the Know Your Rights poster.