Staff Software Engineer

Who you are

• 8+ years of professional software development experience
• 6+ years of hands-on experience with Java
• 3+ years of experience with TypeScript
• 3+ years of experience with React (or React Native), including modern architectures and tooling in the React ecosystem (Hooks, Components, Context, state management)
• Excellent written and verbal communication skills, with experience in cross-functional collaboration — especially translating between marketing goals and engineering tradeoffs
• Proven experience building high-quality, high-performance web and mobile UIs to spec — including responsive, SEO-conscious, conversion-optimized pages
• Proficient in Java frameworks and tools used at Flex, including Spring (core/web/boot), Gradle, JUnit, and JVM (memory/performance tuning, GC)
• Experience with service-oriented architecture, REST APIs, webhooks, message queues, event-driven design, and scalable architectures
• Experience with AWS (EKS, Aurora RDS, Elasticache, DynamoDB) and containerization tools
• Comfort integrating and debugging third-party APIs and SDKs where you don't control the contract, including rate limits, partial failures, and reconciliation
• Experience on a growth, marketing engineering, or MarTech team
• Hands-on experience with platforms such as Braze, Singular/AppsFlyer/Branch, Google Tag Manager, Amplitude, LaunchDarkly, or the Meta/Google/TikTok/Apple ad and conversion APIs
• Familiarity with attribution, identity resolution, and conversion tracking, and the privacy constraints they operate under (consent management, state privacy laws, platform tracking restrictions)
• Experience with A/B testing and experimentation frameworks, web performance optimization, and headless/CMS content tooling
• Experience with big data platforms and tooling, including Snowflake
• Proficient in CI/CD systems (preferably GitHub Actions), git, and automation; observability tools such as DataDog; and Infrastructure as Code using CDK or Terraform
• Skilled at elevating team standards through best practices and mentoring junior engineers

What the job involves

• Flex is looking for a Staff Software Engineer to join our MarTech (Marketing Technology) team
• This role involves spearheading the implementation of the platforms, services, and customer-facing web experiences that power how Flex finds, wins, and keeps customers
• MarTech is the connective layer between our ad platforms, website, messaging systems, analytics, and product data
• We turn marketing spend into a measurable, repeatable growth engine, and give marketing the ability to launch, test, and personalize campaigns without hand-built engineering each time
• It's a team with a broad surface area, owning growth engineering end to end across Lifecycle Marketing (email & SMS), Performance Marketing (paid acquisition), Brand (social and every getflex.com property), and Product Marketing
• Here are some of the projects and systems in MarTech you'll have opportunities to work on:
• Incentive platform — event-driven credit assignment for referrals, affiliates, and campaigns
• Attribution and measurement — conversion APIs, identity resolution, and spend/event pipelines behind our acquisition cost reporting
• Customer-facing web — the full getflex.com surface area and paid-acquisition landing pages
• Lifecycle messaging — campaign orchestration, audience syncs, and event-driven notifications
• What you'll do:
• Build and own full-stack marketing services and web experiences that drive customer acquisition and retention
• Design and develop 24/7 high-scale APIs, event-driven services, and data pipelines. Our stack runs on AWS: Java and Spring Boot for the existing backend code base; TypeScript and React for web
• Build measurement into everything we ship, and integrate third-party ad, analytics, and messaging platforms behind durable abstractions
• Work closely with marketing, data, product, design, and engineering peers to launch features and experiments across web and mobile

The application process

• Mandatory Flex-sponsored New Hire Onboarding (Mon-Wed of your first week) in person at our NYC headquarters

Benefits

• Medical, Dental & Vision: Your healthcare will be available from Day 1— giving you immediate peace of mind — with best in class coverage and options.
• Parental Leave: Step away with paid time off to focus on family and life’s newest chapter.
• NYC HQ: Collaborate in our lively New York headquarters, with new office space on the way!
• 401(k) Retirement Savings: Plan ahead with our 401(k) program to grow your future. And starting early 2026, employees will be eligible for a company match!
• Flex Giving: ‍Flex Giving empowers employees to support local nonprofits advancing housing stability in the communities we call home.
• Employee Assistance Fund: ‍Confidential financial support to teammates facing unexpected hardships or emergencies.
• Hybrid Work Policy: Work flexibly from home, with in-person collaboration and events that matter.
• Unlimited PTO + Holidays: Take the time you need— whether that’s a vacation, recharge, or simply a long weekend
• Free Flex Subscription: As a Flex employee, you'll have full access to our services without charge.
• GrubHub Credit: Enjoy meal credits while in the office, so you’re fueled for the workday ahead.