Mid Frontend Developer Jobs in Princeton, NJ (NOW HIRING)

What Your Experience Will Be
You'll join Slang's Engineering team as a Software Engineer, contributing across our core product areas including telephony infrastructure, AI-powered conversation features, and application functionality. Your work will help restaurants automate customer interactions and improve service through natural conversation. You'll spend roughly 90% of your time developing backend services in Kotlin, with occasional contributions to React/TypeScript frontend features as needed. Your work will directly impact thousands of restaurant interactions daily, helping businesses streamline operations and deliver better customer experiences.
You'll report to the Engineering Manager, collaborating closely with product managers, conversation designers, and fellow engineers. The role requires attendance at key ceremonies including daily standups at 1:00 PM ET, bi-weekly cycle planning, and weekly Show & Tell sessions. As a software engineer, you'll use modern collaboration tools like Slack, GitHub, and video conferencing to stay connected with the team. Once ramped up, you'll have opportunities to mentor junior and other mid-level engineers through code reviews and pair programming sessions.
Why You Belong Here and How You Will Grow
Our engineering culture emphasizes pragmatic solutions, continuous learning, and collaborative problem-solving. We believe in domain-driven design, comprehensive testing, and building systems that gracefully handle the complexities of real-world restaurant operations. You'll work alongside engineers who are passionate about creating reliable, scalable conversational experiences and who regularly share knowledge through Show & Tell sessions and detailed technical documentation.
As a software engineer, you'll gain exposure to cutting-edge conversational AI technologies, telephony systems at scale, and modern cloud-native architectures. You'll deepen your expertise in Kotlin and functional programming while working with production systems handling real-time voice interactions. The cross-functional nature of the role will accelerate your growth toward senior engineering roles. You'll learn from experienced engineers while contributing your own perspectives to architectural decisions and technical standards.
What Success Looks Like

• Design and implement scalable Kotlin backend services following domain-driven design principles, with comprehensive error handling and testing
• Develop and maintain GraphQL APIs that efficiently serve both internal and external clients
• Create robust integrations with Twilio telephony services and Dialogflow conversational AI, handling edge cases and failure scenarios gracefully
• Design efficient Firestore data models that balance performance, cost, and maintainability
• Implement comprehensive observability including logging, metrics, tracing, and actionable alerting
• Deliver production-ready code with appropriate test coverage (unit, integration, and end-to-end tests)
• Participate actively in code reviews, providing constructive feedback and incorporating suggestions
• Document technical decisions, API contracts, and system architecture clearly
• Deploy containerized applications to Google Cloud Platform following cloud-native best practices
• Occasionally build or update React/TypeScript frontend components that provide intuitive interfaces for restaurant staff and customers
• Collaborate effectively with cross-functional teams to refine requirements and deliver features that meet business needs
• Contribute to technical design discussions and help establish coding standards and best practices

What You Will Bring

• 3-5 years of professional software development experience, primarily in backend systems
• Strong proficiency in at least one JVM language (Kotlin, Java, or Scala) with understanding of functional programming concepts
• Experience building and consuming RESTful or GraphQL APIs
• Familiarity with NoSQL databases and data modeling concepts
• Experience with containerization (Docker) and cloud platforms (AWS, GCP, or Azure)
• Strong understanding of software testing practices and test-driven development
• Excellent debugging and troubleshooting skills
• Basic familiarity with React and TypeScript (occasional frontend adjustments may be needed)
• Ability to work independently and manage time effectively in a remote/hybrid environment
• Strong written and verbal communication skills for remote/hybrid collaboration
• Willing and able to take a week on-call shift roughly every two months

Preferred

• Experience with Kotlin specifically and its idioms
• Familiarity with GraphQL schema design and implementation
• Experience with Google Cloud Platform services (Firestore, Cloud Functions, Pub/Sub)
• Knowledge of telephony systems (Twilio or similar) and webhook integrations
• Experience with conversational AI platforms (Dialogflow, Lex, or similar)
• Infrastructure as code experience with Terraform
• Understanding of event-driven architectures and distributed systems patterns
• Experience with observability tools and practices (structured logging, distributed tracing)
• Previous experience working in a fully remote or hybrid company
• Interest in restaurant/hospitality technology domain

How Work Affects My Life
This software engineering position offers the flexibility of remote/hybrid work with competitive hourly compensation commensurate with mid-level engineering market rates. You'll have the autonomy to structure your 40-hour work week while maintaining core collaboration hours with the team. The role provides an opportunity to work on meaningful technology that directly impacts small business owners and their customers, helping restaurants thrive through innovative conversational AI solutions.
Through this role, you'll gain valuable experience working with enterprise-grade systems and modern AI technologies, positioning you for future senior engineering opportunities. The exposure to production telephony systems, conversational AI, and scalable cloud architectures will expand your technical portfolio and worldview on how technology can transform traditional industries. You'll be part of building solutions that make restaurant operations more efficient and customer experiences more delightful, contributing to the digital transformation of the hospitality industry.
Deliverables:
This scope of work defines the responsibilities and deliverables for a software engineer supporting Slang's development. The engineer will focus primarily on implementing robust, scalable backend services in Kotlin while occasionally contributing to frontend features in TypeScript/React, all powering conversational solutions for full-service restaurants.
Software Development

• Design and implement backend services using Kotlin and the JVM ecosystem (primary focus)
• Develop GraphQL queries and mutations for client-server communication
• Contribute to React frontend components and features as needed
• Create modular, testable code following domain-driven design principles
• Implement proper error handling, logging, and graceful degradation patterns
• Write comprehensive unit and integration tests across the stack

Data Modeling and Storage

• Design and implement Firestore data models that optimize for performance and maintainability
• Create efficient data access patterns and queries
• Implement data migration scripts and schema evolution strategies
• Ensure data consistency and integrity across distributed systems
• Design GraphQL schemas that effectively represent domain models

Telephony and AI Integrations

• Develop and maintain integrations with Twilio for voice and messaging capabilities
• Implement Dialogflow conversational flows and webhook handlers
• Create fault-tolerant communication between telephony providers and internal services
• Handle edge cases and error scenarios in telephony workflows
• Implement retry logic and circuit breaker patterns for external service calls

Frontend Development (as needed)

• Implement React components using TypeScript
• Integrate frontend with GraphQL APIs
• Ensure responsive and accessible UI implementations
• Write unit tests for React components
• Collaborate with product team on user experience improvements

Cloud Services Integration

• Develop containerized applications using Docker
• Deploy and manage services on Google Cloud Platform
• Ensure services follow cloud-native best practices for scalability and resilience
• Integrate with GCP services (Cloud Functions, Pub/Sub, etc.) as required
• Provision new infrastructure using Terraform as needed under the guidance of platform engineering

Observability and Monitoring

• Implement comprehensive logging, metrics, and tracing
• Create dashboards and alerts for service health monitoring
• Develop diagnostic tools to aid in troubleshooting production issues
• Ensure all services provide actionable insights into their behavior and performance

Deliverables
Code and Documentation

• Production-ready Kotlin backend code following established coding standards
• TypeScript/React frontend code when assigned frontend tasks
• GraphQL schema documentation and query examples
• Technical design documents for new features and architectural changes
• Contribute to code reviews for team members' pull requests and submit your code for code reviews

Testing and Quality Assurance

• Automated test suites with adequate code coverage for backend services
• Frontend component tests for any UI work delivered
• Integration tests for all external service dependencies
• Bug fixes and issue resolution within agreed SLAs

Collaboration and Communication
Team Integration

• Participate in daily standups and bi-weekly cycle planning sessions
• Collaborate with Platform & Data pods on shared initiatives
• Provide technical input during architecture discussions
• Share knowledge and progress on work during weekly Show & Tell sessions
• After ramping up, mentor junior/mid-level engineers through code reviews and pair programming sessions

Stakeholder Communication

• Provide regular status updates on assigned tasks
• Communicate technical trade-offs and implementation options
• Document technical decisions and their rationale
• Participate in cross-functional meetings as needed

Technical Standards
Code Quality

• Follow Kotlin idioms and best practices for backend development
• Use TypeScript effectively with proper type safety for frontend work
• Use dependency injection and maintain loose coupling
• Write self-documenting code with meaningful variable and function names
• Maintain consistent code formatting using agreed-upon linters

Compensation & Location
Compensation for this role is location-based and benchmarked against local market data aligned to the employee's primary work location. Total compensation includes a mix of cash and equity and may vary by location, role level, and experience. Our range is therefore wide and not meant as a negotiation range.
Our Vision
Calling a business shouldn't feel like a robot-hostage situation, where you're forced to listen to horrible music and can't reach a human, while enduring a soulless voice uttering "I'm sorry I didn't quite get that" on repeat for eternity. (shudder) That's why we started Slang AI We use the latest AI and audio wizardry to make transacting via voice so enjoyable it's more human than human. By 2030, we will save businesses and consumers 1 billion minutes of precious time while transforming voice channels into the preferred mode of communication (it's faster and easier than text).
We have backgrounds building product at companies like Spotify, Buzzfeed, the New York Times, and OpenTable -shipping experiences that have reached hundreds of millions of users. Now, we're using our backgrounds to start a new culture, one that puts product and human-centered design above all else while fostering constant learning and growth. Sound like something you'd like to be part of? Get on board.
Our Engineering Values
How we work matters as much as what we build. Four values guide the engineering team at Slang:

• Start Less, Finish More - Focus is a choice. We ruthlessly prioritize, ask "why" before committing, and say no early so we ship meaningful work instead of accumulating half-finished efforts.
• Teamwork & Collaboration - Great engineering doesn't happen in isolation. We share knowledge and load, assume best intentions, and work with each other, not just alongside each other.
• Alignment & Communication - We move fast because we're aligned. We give feedback directly, speak up early, commit fully once a decision is made, and operate with low ego - caring more about the right outcome than being right.
• Quality & Craft - Shortcuts compound. We test before we ship, manage tech debt deliberately, and right-size solutions - not out of perfectionism, but out of respect for the people who