Senior Full Stack Engineer
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Before you apply
Salary$175k – $225k
LocationNew York City
Also inBrooklyn, NY - 3 days/week in office (Mondays required + 2 flexible days)
Work modehybrid
Typefull-time
SenioritySenior
Experience5+ yrs
DepartmentFonzi
EquityIncluded
Company size11–50 people
PostedSep 5, 2025 · 1y ago
Verified live13h ago
May no longer be actively hiring
Posted by the company on Sep 5, 2025
At a glanceSummarised by Seekless from the posting.
Strong TypeScript expertise
Full-stack proficiency with Node.js, React, and Next.js
Backend focus: stronger and more passionate about backend development
PostgreSQL experience with ability to write efficient queries and design schemas
Experience building and deploying serverless applications
AI integration experience: integrated LLMs and AI models into production applications
Minimum 5 years experience with proven success in fast-paced, ambiguous environments
Product mindset: deep understanding of user experience and how engineering decisions impact business outcomes
Speed with intentionality: ability to ship fast while being deliberate about technical debt trade-offs
Experience with AI prompting and working alongside AI coding assistants
Knowledge of CI/CD pipelines and deployment automation
Experience with cloud platforms (GCP preferred)
Background in marketplace or recruiting technology
Experience working directly with non-technical teams
Skills
TypeScript
Node.js
React
Next.js
PostgreSQL
GCP
Senior Full Stack Engineer
About Fonzi AI
We’re a well-funded, fast-growing startup revolutionizing hiring through AI. Recently launched, we’ve already attracted thousands of top engineers to our platform. Our vision is to build an AI-powered recruiting marketplace that will connect millions of candidates and companies, where AI recruiters learn what you do, what you’re interested in, and match you to perfect opportunities automatically.
The Role
We’re seeking a Senior Full Stack Engineer who can own projects end-to-end and ship fast without sacrificing code quality. This is a backend-leaning full-stack role where you’ll build the core platform that powers our AI-driven marketplace. You’ll work directly with our technical lead to architect and implement features that directly impact how thousands of candidates and companies connect.
This isn’t just another engineering role - you’ll be a true product engineer who understands that every line of code impacts real users. You’ll collaborate closely with our recruiting and marketing teams, translating business needs into technical solutions while maintaining the delicate balance between speed and scalability that defines successful startups.
What You’ll Do
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Drive complete feature development end-to-end, from initial design through production deployment
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Build robust backend systems using TypeScript and Node.js while creating intuitive frontend experiences with React and Next.js
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Integrate AI capabilities into applications
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Work alongside AI models to accelerate development while maintaining code quality
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Balance rapid delivery with long-term architectural considerations
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Collaborate directly with recruiting and marketing teams to understand and solve their technical challenges
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Ship code fast while maintaining awareness of long-term architectural implications
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Shape product direction when requirements are still forming - you’ll help define the ‘what’ not just build the ‘how’"
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Communicate technical concepts clearly to non-technical stakeholders
Required Experience
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Strong TypeScript expertise: This is our primary language and you’ll use it daily
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Full-stack proficiency: Solid experience with Node.js, React, and Next.js
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Backend focus: While full-stack, you should be stronger and more passionate about backend development
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Database skills: PostgreSQL experience with ability to write efficient queries and design schemas
•
Serverless architecture: Experience building and deploying serverless applications
•
AI integration experience: You’ve integrated LLMs and AI models into production applications
•
Startup DNA: Minimum 5 years experience with proven success in fast-paced, ambiguous environments
•
Product mindset: Deep understanding of user experience and how engineering decisions impact business outcomes
•
Speed with intentionality: Ability to ship fast while being deliberate about technical debt trade-offs
Preferred Experience
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Experience with AI prompting and working alongside AI coding assistants
•
Knowledge of CI/CD pipelines and deployment automation
•
Experience with cloud platforms (GCP preferred)
•
Background in marketplace or recruiting technology
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Experience working directly with non-technical teams
What Makes You Successful Here
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Extreme ownership: You take projects and run with them without constant oversight
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Communication excellence: You can explain complex technical concepts to anyone
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Adaptability: Thrive in a dynamic environment where priorities evolve based on business needs
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Business acumen: You understand how your code impacts revenue and user experience
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Self-directed: Thrives in minimal structure with loose sprint cycles
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Speed-focused: Default to shipping and iterating rather than perfecting
What Makes This Special
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High impact: Your code directly shapes how thousands of people find their next opportunity
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Technical autonomy: Own entire features and make architectural decisions that matter
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Cross-functional exposure: Work directly with recruiting, marketing, and leadership teams
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AI at the edges: Build with cutting-edge AI tools while focusing on solid engineering fundamentals
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Growth trajectory: Join early enough to influence technical direction as we scale
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No red tape: Streamlined decision-making and flat organizational structure
Location
Brooklyn, NY - 3 days/week in office (Mondays required + 2 flexible days)
Compensation
$175,000 - $225,000 base salary + meaningful equity
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