Senior Software Engineer

Proxima•New York City, NY

5d•Hybrid

About The Position

Proxima is the data and AI platform powering the next generation of ecommerce growth. Built on the industry's largest 1st party ecommerce network — 100M+ consumer profiles, 500M+ ecom transactions, and $60B+ in transaction volume across 2,200+ brands — Proxima enables brands to reach, understand, and convert customers with precision and performance. Our data is deterministic (real names, emails, and addresses from actual orders, not inferred from sessions), granular (full SKU-level receipt data), and point-in-time (timestamped history that enables recency scoring and ML without look-ahead bias). Headquartered in New York, we're a team of operators, builders, and ecommerce veterans solving the hardest problems in modern customer acquisition. About the Role We're looking for a Senior Full Stack Engineer to help build the AI-driven products at the core of our platform. You'll work directly with our proprietary dataset, real-time, anonymized cross-brand transaction data, to build tools that help independent brands find their best customers and help consumers discover brands they'll love. This is a true full stack role: from custom AI agents and backend orchestration to clean, responsive UIs. If you thrive in fast-moving environments and are energized by pushing the limits of AI-assisted development, we'd love to talk.

Requirements

6+ years of professional software development experience
Proven track record in startup environments — you've shipped fast and worn multiple hats
Strong proficiency in TypeScript, Python, and React
Experience writing production-grade CSS
Solid working knowledge of SQL and relational database design
Demonstrated experience building or integrating AI-powered applications
Daily use of AI-assisted coding tools (Cursor, GitHub Copilot, Claude Code, etc.) — this is a requirement, not a nice-to-have
Comfortable owning projects independently in high-velocity environments
Bachelor's degree or higher in Computer Science, Engineering, or a related field

Nice To Haves

Experience with AI agent frameworks, orchestration tools, or embeddings
Background in data engineering (ETL, dbt, Airflow, etc.)
Familiarity with cloud platforms (AWS, GCP, Azure) and containerization (Docker, Kubernetes)

Responsibilities

Build, maintain, and scale full stack applications using TypeScript and React.
Develop end-to-end features across AI agent interfaces, orchestration layers, and developer-facing tools
Write and style responsive UIs using CSS/SCSS
Design, build, and document backend services and APIs
Query and manage relational databases using SQL
Collaborate cross-functionally to ship high-impact features quickly
Own projects from architecture to deployment in an agile, high-velocity environment
Stay current on modern AI development practices and tooling

Benefits

Competitive base salary and meaningful equity
Comprehensive medical, dental, and vision coverage
HSA and FSA options
401(k)
12 weeks of fully paid parental leave
Unlimited PTO
Summer Fridays from July 4th through Labor Day
Mental health and wellness support through Talkspace, Health Advocate, and One Medical
Commuter benefits
$1,000 annual learning & development stipend
Quarterly team events, both in and out of the office