The Senior Growth Full-Stack Engineer will design and implement experiments to enhance user onboarding and engagement, focusing on rapid deployment and analysis of features.
The Opportunity
We’re looking for a Senior Growth Full-Stack Engineer to join our Activation team at Seamless.AI. This role sits at the intersection of engineering, product, and growth, helping us design, build, and run experiments that accelerate user onboarding, engagement, and activation. You’ll partner closely with growth product managers, designers, and analysts to rapidly ship and iterate on experiments that improve how new users discover value in Seamless.AI.
Responsibilities- Collaborate with growth, product, and data teams to design and implement A/B tests and growth experiments focused on user activation.
- Build, deploy, and maintain full-stack features and experiment infrastructure (frontend + backend).
- Implement and manage feature flagging systems to enable rapid testing and controlled rollouts.
- Work with GrowthBook (or similar experimentation platforms) to set up, track, and analyze experiments.
- Instrument and track user behavior in Amplitude and other analytics platforms to generate insights.
- Write clean, scalable, and maintainable code across the React frontend and Node.js backend.
- Monitor and evaluate experiment outcomes, providing actionable insights and recommendations.
- Balance speed of experimentation with engineering best practices, ensuring quality while moving quickly.
- The #1 goal of this position is to help Seamless.AI increase user activation, feature adoption, and time-to-value. These efforts will maximize customer retention & satisfaction.
Skillset
- 5+ years of experience as a full-stack engineer (startup or growth-focused environment preferred) with SaaS product.
- Strong proficiency in modern JavaScript/TypeScript (React.js, Node.js)
- Proficiency with modern database technologies (PostgreSQL, Vector DBs, OpenSearch, DynamoDB)
- Proficiency with Cloud architecture and scalability best practices, in particular AWS (Lambda, serverless, cloud-native services).
- Hands-on experience with A/B testing platforms (GrowthBook, Optimizely, LaunchDarkly, etc.).
- Familiarity with feature flag systems and controlled experiment rollout strategies.
- Experience with product analytics tools (Amplitude, Segment, Tableau).
- Ability to translate growth hypotheses into technical experiments quickly and iteratively.
- Strong data-driven mindset with the ability to evaluate experiment outcomes statistically.
- Comfortable working in fast-moving, cross-functional growth teams.
Preferred:
- Background in PLG, growth engineering, activation, or onboarding-focused roles.
- Experience with event-driven architecture and scalable systems.
- Familiarity with in-app education & onboarding tooling (e.g., Userflow).
- Familiarity with Pinecone and LLMs.
- Experience building SaaS applications in the B2B or productivity space.
- Bachelor’s degree in Computer Science, Engineering, or a related field (or equivalent practical experience).
- Proven experience delivering full-stack features and experiment infrastructure in a fast-paced environment.
- Demonstrated ability to collaborate across engineering, product, and growth teams.
- Strong problem-solving and analytical skills with a data-first approach.
Since 2015, Seamless.AI has helped sales teams maximize revenue with the world’s first real-time B2B search engine. As one of Ohio’s fastest-growing companies, we’ve earned top industry accolades, including G2’s 2025 Best Software Products (#1 Highest Satisfaction Product), Purpose Jobs’ 2024 Best Places to Work, and LinkedIn’s Top 50 Tech Startups (2020, 2022, 2023). We are committed to a diverse, inclusive workplace and do not discriminate based on race, religion, gender, sexual orientation, age, or other protected statuses. Visa sponsorship is not available; applicants must be authorized to work in the U.S.
Top Skills
Amplitude
AWS
DynamoDB
Growthbook
JavaScript
Launchdarkly
Node.js
Opensearch
Optimizely
Pinecone
Postgres
React
Segment
Tableau
Typescript
Userflow
Similar Jobs
.png)
eCommerce • Fintech • Hardware • Payments • Software • Financial Services
As an SMB Account Manager for Square, you will assist food and beverage clients in utilizing Square's tools, growing their business, and achieving their goals. You will manage a multi-million dollar client base, address customer needs, and collaborate with various teams for optimal service.
eCommerce • Fintech • Hardware • Payments • Software • Financial Services
As a Customer Success Advocate, you will assist Square sellers through phone and email, providing product knowledge and support while handling inquiries and escalations. You'll identify customer needs and improve their experience, requiring adaptability to the evolving product ecosystem.
eCommerce • Fintech • Hardware • Payments • Software • Financial Services
The Staff Product Designer will focus on creating impactful product experiences for sellers, improving engagement and retention through high-craft design on mobile and web platforms.
Top Skills:
AndroidInteraction DesigniOSMobile Applications
What you need to know about the Boston Tech Scene
Boston is a powerhouse for technology innovation thanks to world-class research universities like MIT and Harvard and a robust pipeline of venture capital investment. Host to the first telephone call and one of the first general-purpose computers ever put into use, Boston is now a hub for biotechnology, robotics and artificial intelligence — though it’s also home to several B2B software giants. So it’s no surprise that the city consistently ranks among the greatest startup ecosystems in the world.
Key Facts About Boston Tech
- Number of Tech Workers: 269,000; 9.4% of overall workforce (2024 CompTIA survey)
- Major Tech Employers: Thermo Fisher Scientific, Toast, Klaviyo, HubSpot, DraftKings
- Key Industries: Artificial intelligence, biotechnology, robotics, software, aerospace
- Funding Landscape: $15.7 billion in venture capital funding in 2024 (Pitchbook)
- Notable Investors: Summit Partners, Volition Capital, Bain Capital Ventures, MassVentures, Highland Capital Partners
- Research Centers and Universities: MIT, Harvard University, Boston College, Tufts University, Boston University, Northeastern University, Smithsonian Astrophysical Observatory, National Bureau of Economic Research, Broad Institute, Lowell Center for Space Science & Technology, National Emerging Infectious Diseases Laboratories
