S3 CONNECTIONS LLC
Job Title: Senior Python/React Web Developer
Location: New York City, NY – Onsite, 5 Days/Week
Client: Confidential (Jefferies Project)
Visa Status: Any Working Visa Accepted (3rd-party candidates allowed)
Submission: Super Urgent – Please Submit via GH
Client Feedback Note:
"Candidates must have strong React.js experience. Previous submissions lacked depth in front-end skills."
Role Description:
We are looking for a Senior Full-Stack Web Developer with strong backend experience in Python 3.7 and solid expertise in React.js (v14+) to join the Internal Data Marketplace project at Jefferies. This is a highly visible, hands-on development role, best suited for candidates who can work onsite full-time in NYC and contribute to robust, production-grade engineering systems with clear, scalable code.
Core Responsibilities:
Develop and maintain scalable web applications using Python 3.7+ and web frameworks like Flask or Django
Design and implement RESTful APIs and integrate with backend SQL (PostgreSQL/MySQL) and NoSQL (Snowflake preferred) data stores
Build intuitive and performant front-end interfaces using React.js (v14+), HTML5, CSS3, and JavaScript
Apply object-oriented design patterns and use SQLAlchemy or similar for ORM
Deploy containerized applications using Docker and manage CI/CD pipelines in AWS Cloud environments
Write unit tests and ensure application reliability using Python testing frameworks
Work in an Agile/SCRUM team structure and communicate clearly with cross-functional teams
Required Skills:
7–10 years of professional web development experience
Strong Python 3.x development skills with Flask or Django
Deep React.js expertise – must have experience with version 14+
Experience connecting web applications to SQL and NoSQL databases
Solid understanding of Python OOP, multithreading, and data structures (e.g., Pandas)
Proficient in Git, Bitbucket, VS Code, or Anaconda environments
Familiarity with CI/CD, Docker, and AWS deployment
Experience using Agile methodologies and tools like JIRA
Nice-to-Haves:
Experience with DuckDB or Apache Arrow
Application-level caching strategies (Redis/Memcached)
Kubernetes or Helm deployment experience
Client Feedback Note:
"Candidates must have strong React.js experience. Previous submissions lacked depth in front-end skills."
Role Description:
We are looking for a Senior Full-Stack Web Developer with strong backend experience in Python 3.7 and solid expertise in React.js (v14+) to join the Internal Data Marketplace project at Jefferies. This is a highly visible, hands-on development role, best suited for candidates who can work onsite full-time in NYC and contribute to robust, production-grade engineering systems with clear, scalable code.
Core Responsibilities:
Develop and maintain scalable web applications using Python 3.7+ and web frameworks like Flask or Django
Design and implement RESTful APIs and integrate with backend SQL (PostgreSQL/MySQL) and NoSQL (Snowflake preferred) data stores
Build intuitive and performant front-end interfaces using React.js (v14+), HTML5, CSS3, and JavaScript
Apply object-oriented design patterns and use SQLAlchemy or similar for ORM
Deploy containerized applications using Docker and manage CI/CD pipelines in AWS Cloud environments
Write unit tests and ensure application reliability using Python testing frameworks
Work in an Agile/SCRUM team structure and communicate clearly with cross-functional teams
Required Skills:
7–10 years of professional web development experience
Strong Python 3.x development skills with Flask or Django
Deep React.js expertise – must have experience with version 14+
Experience connecting web applications to SQL and NoSQL databases
Solid understanding of Python OOP, multithreading, and data structures (e.g., Pandas)
Proficient in Git, Bitbucket, VS Code, or Anaconda environments
Familiarity with CI/CD, Docker, and AWS deployment
Experience using Agile methodologies and tools like JIRA
Nice-to-Haves:
Experience with DuckDB or Apache Arrow
Application-level caching strategies (Redis/Memcached)
Kubernetes or Helm deployment experience