Staff Frontend Engineer

ZenRows

REMOTE | FULL-TIME Born in Bilbao, growing everywhere. ZenRows is one of Europe's fastest-growing startups, and we've been fully remote since day one. We build the infrastructure that lets thousands of companies, in e-commerce, finance, real estate, and AI, extract data from the web reliably and at scale. Our stack isn't a CRUD app. We orchestrate thousands of CPU cores, handle hundreds of millions of requests per day, push terabytes of outbound traffic monthly, and simulate human behavior to stay ahead of the most advanced anti-bot systems on the market. The engineering problems here are real, and your work will be visible in production within weeks. THE ROLE You will own critical infrastructure components that ingest, enrich, and route billions of data points — ensuring performance, reliability, and horizontal scalability. Your work will directly impact throughput, customer SLAs, billing accuracy, and platform reliability. As our Staff Software Engineer, you'll operate at the intersection of deep system design, hands-on implementation, and technical leadership. You’ll collaborate with other engineers to design fault-tolerant, observable, and cost-efficient systems that support our distributed workloads. We’re a remote-first company with a fast-paced, high-impact culture. In this role, you’ll work closely with our CEO, Aurken, and our Director of Engineering, Alina. WHAT YOU'LL WORK ON SCRAPING PLATFORM RELIABILITY & SCALE * Own the availability and success rate of the scraping API — the core product metric * Drive architectural improvements that increase throughput and reduce failure rates across diverse target sites * Design systems that degrade gracefully, self-heal, and adapt to shifting detection patterns without human intervention DISTRIBUTED JOB EXECUTION * Design and evolve the async execution architecture that processes millions of concurrent tasks across nodes and regions * Build robust retry strategies, idempotency, dynamic routing, rate limiting, and prioritization * Own scheduling infrastructure for recurring, event-driven, and user-triggered workflows RELIABILITY & OBSERVABILITY * Define and enforce SLAs for both the scraping API and job processing systems * Build alerting and dashboards for failure modes, success rate regressions, throughput anomalies, and retry storms * Lead incident response and post-mortems; participate in on-call responsibilities for the systems you own TECHNICAL LEADERSHIP * Contribute meaningfully to architecture decisions — not just implementation * Raise the bar in design reviews and engineering standards across the team * Mentor peers and drive adoption of sound distributed systems practices WHAT WE'RE LOOKING FOR REQUIRED * 10+ years of backend engineering experience, with meaningful time spent building and operating high-throughput, high-availability distributed systems * Strong fundamentals in concurrency, fault tolerance, consistency models, and systems design * Hands-on experience with queueing and messaging systems (SQS, Kafka, RabbitMQ, Pub/Sub, BullMQ, or similar) * Comfortable operating at scale — tens of millions of requests or events per day, across multiple nodes or regions * Solid production instincts: you think about retries, deduplication, backpressure, and observability before writing the first line * Clean, maintainable code in Go (or a comparable backend language) * Experience with distributed tracing, metrics, and logging (OpenTelemetry, Prometheus, Grafana, or equivalent) * Clear communicator — you can drive a technical debate and explain complex tradeoffs to non-engineers alike BONUS * Experience with browser automation at scale (Playwright, Puppeteer, or similar) * Familiarity with proxy infrastructure, TLS fingerprinting, or HTTP-level anti-bot patterns * You've designed or operated a workflow engine, job scheduler, or orchestration system * You have a war story from a system that broke badly in production — and clear lessons learned from it * Multi-cloud deployment experience WHAT MAKES THIS DIFFERENT * Full ownership. You'll own systems end-to-end — design, deployment, and operations. No handoffs to an ops team, no waiting for someone else to ship your work * Direct impact. The systems you build directly affect customer SLAs, billing accuracy, and the core product success rate. You'll feel it * No layers. You'll work closely with our CEO and Director of Engineering — both technically deep — without three layers of management in between * No methodology theater. We skip the ceremony and give you a horizontal view of the problem. You decide where you can have the most impact WHY YOU WILL LOVE WORKING HERE… * Our people crave ownership and opportunity over everything else. We offer responsibility and scope to do things in your role that you can only dream of in similar roles in larger companies. * We have a CEO who values world-class talent over everything else. Trust and respect are earned, and with them come reward and recognition like nowhere else. * In a world where it feels like everyone is being called back to being in an office, we operate a truly 100% remote approach that allows you to work from anywhere you choose. Forget Agile, Scrum, Lean... or whatever development methodology is trendy this week. We give you a horizontal view that enables you to identify where you think you can contribute the most. We have fun! The above may sound like we are all about work, but we put a lot of focus on ensuring our culture is one that our people enjoy, which lets you build lasting friendships and grow both personally and professionally.

Lunar

About Us: Lunar is a stealth technology company building a new type of software platform for health systems. We are on a mission to revolutionize healthcare with cutting-edge, AI-powered software designed to help every hospital deliver world-class care for their patients. Our platform is already the core backbone of health systems today, transforming clinical and operational workflows at scale with the world’s first AI-native hospital information system. This next-generation platform is a fundamental rebuild of the information infrastructure that runs health systems. All of it – from doctors, nurses, pharmacists, lab technicians, coders, billers, supply chain, and even patients – Lunar’s software powers everything, soup-to-nuts. We believe that this mission is the moon landing of healthcare – something so consequential and ambitious that most people believe it to be impossible. Backed by Silicon Valley’s preeminent venture capital firms, we believe in the power of a high performance team of seasoned professionals operating at the peak of their abilities. We value people who are driven, curious, have sound judgement, and care about doing the best work of their careers. We build rich, reactive interfaces in TypeScript and React, talking to our backend over GraphQL - where the UI updates the instant the underlying clinical data changes. On the backend, we've embraced Elixir for its fault tolerance, concurrency, and scalability - essential for handling real-time patient data in mission-critical settings like Emergency Departments, ICUs, and Operating Rooms. We are looking for a Staff Frontend Engineer who's excited to tackle some of the hardest interface and interaction problems in healthcare - and do it with a small, fast-moving, and deeply mission-driven team. If you care about crafting clean, robust, intuitive interfaces and want to rebuild from scratch the software that clinicians rely on every day, we'd love to talk. Here are some deep technical problems you may tackle in your first 6 months: * Build a clinical design system from scratch: Design and ship a component library and design system that brings consistency, speed, and polish to every screen a clinician touches. * Push hospital workflows into the modern age: Rethink and rewire how clinicians move through the software - and turn confusing, click-heavy workflows into fast, keyboard-driven, intuitive experiences that clinicians love, not tolerate. * Render real-time clinical data, instantly: Build interfaces that reflect live patient data - vitals, orders, labs, alerts - the moment it changes, with no lag, in environments like the ED, ICU, and OR where a half-second matters. Architect the data layer, caching, and subscription patterns over GraphQL that make that possible. * Make interfaces that never fail under pressure: Engineer for accessibility, resilience, and performance so the UI holds up in high-stakes, high-stress settings - including degraded networks and edge cases that would break an ordinary web app. * Turn complexity into clarity: Take dense clinical and operational data and shape it into clear, glanceable, decision-ready interfaces for doctors, nurses, pharmacists, and administrators. * Define the frontend from first principles: Set the patterns, state management, and rendering architecture - balancing developer velocity against the reliability bar of mission-critical software. Your Experience:  * Minimum of 10 years of professional software engineering experience, with deep focus on frontend. * Expertise across the frontend stack including TypeScript, JavaScript, React, HTML, CSS, browser internals, rendering performance, state management and building real-time, reactive UIs against GraphQL APIs * Comfortable adopting new tools as needed (we use Elixir/Erlang, Phoenix, Postgres and AWS in the backend). * Experience with client-side data loading and management: caching, freshness, ownership, and how to optimize push updates * Understanding of the browser rendering cycle, how and when the DOM decides what to repaint, and the instinct to profile and optimize for a responsive, data-dense interface. * Well-versed in modern React patterns and functional programming principles, including advanced use of custom hooks to build performant, maintainable, and reusable component architectures at scale. * Deep fluency with async control flow in JavaScript (Promises, async/await) and a track record of diagnosing race conditions, ordering issues, and unhandled rejections in real-time systems. * Strong ability to work in a fast-paced, collaborative, and innovative team environment. * Exceptional problem-solving skills, with a track record of tackling challenging engineering problems. * Intellectually curious with a growth mindset - able to tackle novel challenges through applying strong fundamentals and first principles thinking. * Familiarity with open-source technology and a desire to explore and experiment with new solutions. * Experience building 0-1 with a strong product sense. * Excellent communication skills and the ability to articulate technical decisions, trade-offs, and best practices. * A passion for making a meaningful impact in the healthcare industry through software innovation is a plus. Hospitals are some of the most complex, under-served environments in all of tech. We're bringing the best of modern software practices to an industry that's been left behind - and building tools that clinicians love, not tolerate. If you're an engineer who wants to work on meaningful problems with real-world impact, this is your chance. At Lunar, we know our greatest strength is the diverse blend of backgrounds, experiences, and ideas that our team members contribute. We’re passionate about healthcare, but we are also passionate about creating an inclusive workplace where every unique talent and perspective is not just respected, but celebrated. We thrive on embracing differences and are fully committed to fostering a fair, supportive, and dynamic environment where everyone has the opportunity to shine. All applicants will be considered for employment regardless of race, color, religion, sex, sexual orientation, gender identity, national origin, veteran or disability status.

PPRO

At PPRO, our mission is to simplify access to local payment methods and our vision is to enable the sale of goods and services to anyone in the world using their preferred way to pay. We empower partners such as Ant Group, PayPal and Stripe to access new markets, connect with more customers, and accelerate their growth. Our strength lies in our diverse global team with 50+ nationalities and 10+ international locations- all united around one goal – to deliver the best possible products and services to our partners and customers. While our company mission is to keep innovating global commerce, our internal mission is to #chooseaction, #beopen, #thinkcustomer, #gofurther and #wintogether The Purpose: At PPRO, our Frontend Platform team is transforming how our products are built and shipped - unlocking a frictionless, scalable path to millions of customers worldwide. We own the end-to-end frontend architecture that powers dozens of dynamic brands and products across Latin America and Europe, through a modern micro frontend ecosystem using Module Federation. Staff Software Engineers drive PPRO's most significant decisions, leaving a lasting impact on our technical strategies, system landscape, and culture. Operating within a cross-functional team, you will solve complex technical problems, lead architectural choices, and mentor fellow engineers while coding alongside them. Ultimately, you'll build the foundations of our micro frontend platform, shaping how independent teams ship UI at scale without stepping on each other's toes.