(Senior) Backend Engineer (Golang) - Balance Management

Flo Health

500M+ downloads. 80M+ monthly users. A decade of building – and we’re still accelerating. Flo is the world’s #1 health & fitness app worldwide on a mission to build a better future for female health. Backed by a $200M investment led by General Atlantic, we became the first product of our kind to reach a $1B valuation in 2024 – and we’re not slowing down. With 7M paid subscribers and the highest-rated experience in the App Store’s health category, we’ve spent 10 years earning trust at scale. Now, we’re building the next generation of digital health – AI-powered, privacy-first, clinically backed – to help our users know their body better. The job Build systems that power the #1 Health App for Women We’re not a startup guessing what might work anymore, we’re operating at serious scale. Flo is used by 1 in 4 women aged 18–44 in the US. And we just hit our biggest month ever with 8.6M installs and a 2.8M MAU jump. The engineering behind that? Complex, distributed, secure and yours to help shape. At Flo, backend engineering is core product work. We build: * Data-driven health insights that genuinely change lives * Distributed systems that stay fast, available and scalable under massive real-time demand * Privacy-first features like Anonymous Mode -  recognised in TIME’s Best Inventions * Tooling and platforms that help Flo’s teams move faster, with fewer bottlenecks We’re tech-agnostic when hiring for backend. If you’ve built and run distributed systems and want to work in Scala (or already do), great. We’ll support your ramp-up. What matters most: you can solve problems, own outcomes, and keep learning. Your Experience You’ll thrive here if you: * Have 7+ years’ experience building distributed backend systems * Know what it takes to make systems fast, reliable and secure and when to prioritise each * Are fluent in Java, Scala, Python or similar (and curious enough to learn Scala with us) * Get DevOps, databases (SQL and NoSQL) and love designing APIs that just work * Have a strong handle on writing clean, documented, version-controlled code * Take ownership, show initiative and don’t wait to be told * Are product-minded and always thinking about the end-user impact Bonus if you’ve worked with: * Stream processing * Public cloud infrastructure (AWS, GCP etc.) What’s in it for you? You’ll join a senior engineering team that moves fast, thinks big and builds tech used by millions daily. You’ll work on meaningful problems with real impact - in health, privacy and scale. This isn’t just code for the sake of code. This is building the future of personalised health. #LI-Hybrid #LI-LM12 Salary Range - gross per month (ranges may vary based on skills and experience) €6.500—€10.000 EUR How we work We’re a mission-led, product-driven team. We move fast, stay focused and take ownership – from brief to build to impact. Debate is encouraged. Decisions are shared. We care about craft, ship with purpose, and always raise the bar. You’ll be working with people who take their work seriously, not themselves. It takes commitment, resilience, and the drive to keep going when things get tough. Because better health outcomes are worth it.  What you'll get We support impact with meaningful reward. Here’s what that looks like: * Competitive salary and annual reviews * Opportunity to participate in Flo’s performance incentive scheme * Paid holiday, sick leave, and female health leave * Enhanced parental leave and pay for maternity, paternity, same-sex and adoptive parents * Accelerated professional growth through world-changing work and learning support * In-person collaboration and work in a hybrid model, with 3 days per week spent in the office * 5-week fully paid sabbatical at 5-year Floversary * Flo Premium for friends & family, plus more health, pension and wellbeing perks Diversity, equity and inclusion Our strength is in our differences. At Flo, hiring is based on merit, skill and what you bring to the role – nothing else. We’re proud to be an equal opportunity employer, and we welcome applicants from all backgrounds, communities and identities. Read our privacy notice for job applicants.

Sumup

At SumUp, the Global Bank tribe builds the core infrastructure and services that give merchants a digital business account, helping millions of small businesses manage their banking needs easily and reliably. The Transfers Gateway squad connects SumUp’s internal systems to external financial networks across the EU and the UK. We build and run the services that move money through payment schemes every day. The team owns end‑to‑end scheme integrations and operates production services that process real money at scale. You’ll help modernise existing systems while balancing reliability, correctness, and change, making architectural decisions that directly affect uptime and merchant experience across multiple markets. Our tech stack includes Go, AWS, Kafka, PostgreSQL, and Kubernetes, supported by a strong observability toolchain with Prometheus, Grafana, and Honeycomb. We also actively use AI‑assisted development tools such as Cursor, GitHub Copilot, and others. SumUp’s engineering culture is built around ownership. We follow a “build it, run it, improve it” model, with strong observability and a focus on learning. Engineers have clear scope and autonomy, with decisions documented, reviewed, and made collaboratively. The Vilnius team is a core part of the Global Bank domain. We own production systems, shape technical direction, and work closely with colleagues across SumUp’s global offices on critical merchant banking capabilities. Join our Vilnius Team today (Vilnius office). What You’ll Do * Own high availability money movement production services end‑to‑end, including delivery, observability, maintenance, and operational support. * Lead small‑to‑mid sized initiatives and take responsibility for significant parts of larger team’s domain projects. * Lead architectural and design decisions, including system design, data modelling, and API boundaries. * Improve service reliability and quality through testing, monitoring, alerting, and continuous improvement of delivery pipelines. * Operate the systems you build by participating in on‑call rotations, incident response, and post‑incident reviews. * Apply a backend and systems perspective during refinement, identifying risks, dependencies, and technical trade‑offs early. * Collaborate closely with Product, QA, and engineers across teams to deliver end‑to‑end transfer and banking capabilities. You’ll be great for this role if you * Have previously led the implementation of backend services in a modern environment and supported them in production. * Have experience defining technical approaches for loosely defined problems and driving them to completion. * Are comfortable working with cloud‑based systems, containerized workloads, and automated delivery pipelines. * Have strong experience writing and maintaining automated tests and upholding high code quality standards. * Understand system architecture, data modelling, and API design, and can apply these principles pragmatically. * Think beyond individual components and understand how backend decisions impact the overall product and user experience. * Communicate clearly and work effectively with engineers, product managers, and other stakeholders. Any of the following would be considered a plus * Experience working on banking, payments, or other regulated financial systems. * Prior ownership of systems with high operational load, including incident handling and reliability improvements. * Proven use of AI‑assisted or parallelised AI tooling to improve engineering productivity. Why you should join SumUp 🌎 We’re a truly global team of 3200+ skilled professionals from 92+ countries, spread across 4 continents. Join the team from our Vilnius office. 🌈 Commitment to Diversity and Inclusion: be part of a workplace that values and promotes diversity, fostering an inclusive environment where everyone's perspectives are respected and embraced. 🚀 Enrolment onto our Virtual Stock Option programme: you will own a stake in SumUp’s future success 🏖️ Time off: 25 days of paid leave, plus special holidays 🏥 Peace of mind: health insurance through Gjensidige and life & accidental coverage from Ergo 💪 Stay active: gym membership allowance to help you keep fit on your terms 📚Career growth and learning opportunities: We invest in your development through regular training, mentorship programs, SumUp University cohort and a yearly learning budget (2,000 EUR) 💡We take learning and experimentation seriously with Hack Days every second Friday, and entire global Hack Weeks. 🌴 Break4me: 1-month sabbatical after 3 years of service 🔗 Referral Bonus: earn additional rewards by referring talented individuals to join the SumUp team.   Compensation: From senior level in Lithuania is 4,366  to 7,280 Euro Gross p/m + 2000 EUR annual learning budget + Virtual Stock Options. Offer may vary based on skills and experience   About SumUp At SumUp, we’re on a mission to empower small businesses around the world with simple, affordable tools to help them start, run, and grow. More than 4 million merchants across 37 markets trust us as their financial partner — and we’re just getting started. We’re a global team of 3,000+ people from over 90 nationalities, united by curiosity, collaboration, and care. Our core values and culture shape everything we do, fostering inclusion, learning, and belonging. SumUp is proud to be an Equal Employment Opportunity employer, committed to building a safe, respectful, and diverse workplace where everyone can thrive. 👉 Explore more about our culture on our careers site, or follow us on LinkedIn and Instagram. SumUp is proud to be an Equal Employment Opportunity employer, actively seeking and embracing diversity in our workforce. We don't make hiring or employment decisions based on race, colour, religion or religious belief, ethnic or national origin, nationality, sex, gender, gender identity, sexual orientation, disability, age or any other basis protected by applicable laws or prohibited by company policy. Our commitment extends beyond recruitment to creating a safe and respectful workplace where harassment of any form is strictly prohibited. Job Application Tip We recognise that candidates feel they need to meet 100% of the job criteria in order to apply for a job. Please note that this is only a guide. If you don’t tick every box, it’s ok too because it means you have room to learn and develop your career at SumUp.

Nexos

Join the AI revolution. We’re building an all-in-one AI platform to help teams do their best work and automate every routine task you can think of. We’re looking for problem-solvers to turn powerful AI into an easy, no-code tool for teams everywhere.