Staff Software Engineer, Flex
Martech
$170-250k
Salary dependent on location + equity
Flexible rent payment application
Be an early applicant
Flexible rent payment application
501-1000 employees
Be an early applicant
$170-250k
Salary dependent on location + equity
501-1000 employees
Company mission
To help people pay for the things that matter most.
Role
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
Desirable
- 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
- 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
Our take
Many people struggle to pay their rent every month, with a variety of bills hitting their bank accounts simultaneously. Whilst many of these people earn enough money to cover their bills, the inflexible nature of monthly bills can make the all-in-one payment a harder obstacle.
Flex provides a mobile application for the flexible payment of rent, allowing users to pay their landlords through flexible payment plans, reschedule payments when necessary, and protect their funds through Overdraft Protection. The company achieves this by partnering with estate agents and paying their resident's bills upfront, taking on the challenges that landlords would normally have due to late payments.
Flex has experienced extremely rapid growth since its founding which has caused some issues, as it struggled to keep up with the surge in new customers. Having made improvements to its product and scaled its customer service team, it is set to continue providing a service that has come to be highly valued by both tenants and landlords.
Freddie
Company Specialist at Welcome to the Jungle
Insights
10% employee growth in 12 months
Company
Funding (last 2 of 5 rounds)
Feb 2022
$160m
SERIES C
Apr 2021
$46.6m
SERIES B
Total funding: $225.1m
Company 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.
Company HQ
Midtown Manhattan, New York, NY
Leadership
Shragie Lichtenstein
(Co-Founder & CEO)Prior to co-founding Flex in 2019, Shragie co-founded Boundless Reality. They graduated from Yeshiva University in 2015 with a Bachelor's Degree in Finance.
YeTong Shao
(Co-Founder)Prior to co-founding Flex in 2019, YeTong co-founded Boundless Reality alongside Shragie. They graduated from the University of Chicago with a Bachelor's Degree in Mathematic & Economics.
Share this job
View 31 more jobs at Flex