Rust Engineer - Trading Systems

Keyrock

SENIOR DATA ENGINEER ABOUT KEYROCK Since our beginnings in 2017, we've grown to be a leading change-maker in the digital asset space, renowned for our partnerships and innovation. Today, we partner with over 250 team members around the world. Our diverse team hails from 42 nationalities, with backgrounds ranging from self-taught DeFi natives to PhDs. Predominantly remote, we have hubs in London, Brussels, and Singapore, and host regular online and offline hangouts to keep the crew tight. We are trading on more than 80 trading venues, and working with a wide array of asset issuers. As a well-established market maker, our distinctive expertise led us to expand rapidly. Today, our services span market making, options trading, high-frequency trading, OTC, and DeFi trading desks. But we’re more than a service provider. We’re an initiator. We're pioneers in adopting the Rust Development language for our algorithmic trading, and champions of its use in the industry. We support the growth of Web3 startups through our Accelerator Program. We upgrade ecosystems by injecting liquidity into promising DeFi, RWA, and NFT protocols. And we push the industry's progress with our research and governance initiatives. At Keyrock, we're not just envisioning the future of digital assets. We're actively building it. ABOUT THE TEAM AND WHY THE ROLE EXISTS The Central Data Team (CDT) is only a few months old, but data has been Keyrock's lifeblood since day one. We're now building the Keyrock Data Platform to give Keyrockers, and the AI agents working alongside them, the data and context they need to act fast and autonomously within agreed boundaries and aligned with our shared goals. Doing that means taking data from across the company and making sense of it in real time for all the functions that depend on it: trading desks, wealth and asset management, product, risk, finance, compliance, and research to name a few. You'd be one of the early hires in CDT and we expect you to contribute to most of the bigger decisions and build work. The standards we settle on and the way the team ends up working are still open. WHAT YOU’LL DO * Build streaming and batch pipelines that ingest, normalise, and distribute market, trading, and portfolio data, resilient to feed and exchange failures. * Build the self-serve tooling (SDKs, patterns, templates, AI agents) so other teams publish, consume, and build on data products without waiting on us. * Own data contracts and schema evolution. Keep schema changes from turning into multi-team coordination events. * Design the lakehouse and time-series layer around consumer query patterns. * Build and evolve the Data Governance and Data Quality Framework: stale-feed detection, schema validation, range checks, idempotent writes, lineage, ownership, self-healing. * Build the derived analytics the business runs on: cross-exchange spreads, VWAP at depth, order book microstructure for the desks; portfolio views, exposure, performance for wealth and asset management. * Make observability, cost, and performance first-class from day one. * Treat infrastructure as code (Docker, Terraform, CI/CD) alongside our Central Infrastructure Team. * Work in the open: write things down, partner closely with Architecture, Infrastructure, Platform, and the rest of the teams. WHAT WE’RE LOOKING FOR Tools matter less to us than how you think about problems. That said, here's the shape of the person we have in mind. Engineering Craft * 8+ years of building production data systems that other people rely on. * Strong proficiency in Python and SQL: not just being able to write a query, but being able to reason about what the engine is doing with it. * Code that's easy for someone else to read, test, and delete later. * Strong understanding of data modelling for both streaming and analytical workloads. * Efficiency, quality, idempotency, and observability are taken seriously by default. Systems Design * You've designed and operated streaming systems on Kafka, Redpanda, MSK, or Kinesis, and you have opinions about partitioning, consumer groups, offsets, and schema registries. * You've used a time-series store in production (ClickHouse ideally; TimescaleDB, QuestDB, or similar are fine too) and can talk about table design as a function of query patterns. * You've worked with a lakehouse architecture and reason about table layout, partitioning, and compaction as design choices that shape query performance and storage cost. * You build for self-healing and idempotency. Reprocessing is safe, retries don't double-write, and the system recovers without a human in the loop. Operational Readiness * Docker, Terraform, and CI/CD are how you work, not a separate "DevOps" thing. * You think about cost and performance early. * You instrument as you build: logs, metrics, and traces are part of the system from day one. * You design for data quality and governance up front covering contracts, validation, lineage, and ownership How You Think and Work * You reason from first principles when a problem is new, stay pragmatic when it isn't, and update your view when you learn more. * You treat the trading desks, wealth and asset management, product, risk, finance, compliance, and research as customers of what you build, and communicate with them that way. * You optimise for outcomes over output. A smaller, simpler thing that ships and works beats a bigger thing that doesn't. * You take ownership end-to-end: design, ship, operate, improve. * You say what you think including when it's an unpopular take. You change your mind when the argument is better. * You make the people around you better. Reviews are real, juniors grow from working with you, and peers want to work with you again. * You're curious about how markets work. Data engineering on its own won't keep you interested here. * You're honest about what you know and what you don't, and quick to close the gap. * You understand financial market data: order books, trades, reference data, portfolios, exposures. Crypto, TradFi, or both are a strong plus. NICE TO HAVE * Lakehouse experience with Apache Iceberg or Delta Lake. * Familiarity with DataHub or similar metadata/lineage platforms. * Rust. Some of our performance-critical services are written in it. Interest is welcome; fluency isn't required. WHAT YOU’LL GET * A from-scratch mandate. You'll be among the first hires in CDT, and the platform, the standards, and the team culture are yours to shape with us. * Strong partners. Close working relationships with Architecture, Infrastructure, Platform, and the desks themselves. You won't be building data in a vacuum. * Autonomy on how you work. Flexible hours, remote-first, business-hours on-call shared across the team. * A competitive salary package, with various benefits. * A team that likes each other. Regular online get-togethers and a yearly onsite where everyone's in the same room. OUR RECRUITMENT PROCESS We’re after those with the right skills and a conscious choice to join our field. The perfect fit? Someone who’s driven, collaborative, acts with ownership and delivers solid, scalable outcomes. As an employer we are committed to building a positive and collaborative work environment. We welcome employees of all backgrounds, and hire, reward and promote entirely based on merit and performance. Due to the nature of our business and external requirements, we perform background checks on all potential employees, passing which is a prerequisite to join Key

Payflip

Even though we're not actively hiring full-force, Payflip always wants to talk to interesting talent. That's why we stay open to spontaneous applications for the Software Engineer roles. Typically, we are looking for a Software Engineer with 3+ years of experience in this role. Ideally, you have proven experience in all parts of the fullstack spectrum: frontend, backend, infra, mobile etc. 🌟 OUR PRODUCT TEAM We're building our Product team at Payflip for the long run, and are looking for experienced engineers who want to play a role in growing our salary platform, bringing additional expertise on board to grow to an even more excellent product. Our current Product team consists of multiple squads that autonomously own the full lifecycle of the product, pushing it from discovery to production. You'll work together with other experienced engineers, PMs, and the CTO to deliver on an exciting product roadmap. The tech stack at Payflip to achieve this consists of multiple modern technologies. Where core components in our stack are: * React * Node.js (NestJS) * GraphQL * MongoDB We value bringing eagerness & skill in building mature & maintainable solutions with a great DX more than an exact overlap with our tech stack. Experience in all of them is not a must, but willingness & autonomy to learn definitely is. 🧑‍💻 ABOUT YOU You would be a good fit with our team if most of this sounds like you: * Proficiency with most of our core technologies * Strong mastery & knowledge in a certain domain (e.g backend, frontend, infra) that you want to inspire others with, teach best practices, help scale. * Managing technical debt pragmatically with an ability to strategically balance resilience, testing, and documentation with making quick trade-offs in order to ship products that prioritise impact or implementation. * You're a product builder, meaning you think outside of the coding and tech. You approach opportunities & problems in the squad and determine what success looks like, driving it home, collaborating with others in the product team often (designers, PMs, CTO) * Eager to help in constructing our engineering culture & practices. Align with people across squads, leveraging the right documentation and software patterns. * Fluent in English. Above all we value a high internal drive, curiosity and strong potential: convincing us of this in the hiring process is guaranteed to make you a Payflip'er! 👋 ABOUT US Payflip's mission is to become the new salary partner, truly making salaries work. By empowering both employees and HR teams, we: * Create transparency and trust around compensation * Drive financial literacy and wellbeing * Make Belgium’s workforce more resilient, engaged, and prosperous So that in the future, employees get the best out of their salaries, HR teams shift focus from admin to people, and salaries are seen as a tool for growth (not frustration). We are a fresh, fast-growing startup with a happy bunch of software engineers, product specialists, business developers & reward specialists. Becoming part of the Payflip team means that you join a close-knit team where you will take up solid responsibilities. Let’s say that a Payflip’er smells the opportunity of ownership from miles away! 💜 PAYFLIP'S CULTURE Our company culture revolves around 3 pillars: * Transparency * Eagerness to learn * Ownership We are 100% transparent with everything that happens in the company. We tell each other everything. There is not even one Google Drive file in our archive that is not accessible for all. We invest in self-improvement. That is why you have at least 1 day per month that is dedicated to learning. Together with the other members of the reward hub, you try to investigate an interesting market trend or to fix a company inefficiency you choose yourself, with the methodology of your preference. As we are a small team, we’d better all make our hands dirty if we want to step up our game. In order to thrive, you will have to come out of your comfort zone and take up responsibilities, just like all of us. At Payflip, everyone is an entrepreneur! And because we walk the talk, each team member receives meaningful equity of the company (see below). Growing together at its best!  💰 WHAT'S IN IT FOR YOU We want to be as close to our mission and therefore provide the most optimized salary package in the Belgian SME market. You will receive... * Competitive cash salary * Meaningful equity * Top-notch flexible reward plan * Alan healthcare package * Monizze meal vouchers * Remote work as much as you prefer * Home office compensation * Optimised bonus schemes Payflip uses an open salary grid and for this vacancy we're aiming to hire for the B1-2/B2 range. Want to dig deep? Here you'll find a more detailed description of our levels in engineering and their traits. 💬 OUR HIRING PROCESS FOR ENGINEERS We aim to hire the best of the best at Payflip, and throughout the process we want to see candidates bring their best selves to the table. We'll dive into your previous track record and the expertise you're eager to bring, but also collaborate together with the product team to simulate the real job as close as possible. After a quick informal chat with the CTO our interview is composed of 4 rounds: 1. Screening call with two people from the product team (30-45 min, video call) 2. A pair programming session with two engineers, where you are in the driver seat. You'll work in the Payflip codebase, on a real problem not solving a shady algorithm problem. (1h, video call + remote coding) 3. You'll be presented a product + architectural problem and we'll ask you to write a short proposal for a solution. This is the only in person interview and you'll present this to the team in the Brussels office. We immediately couple the next interview to this so you only have to visit the office once 4. In a final stage we'll be going into a behavioral interview where (together with a founder) we'll discuss your leadership vision, collaboration style and ambitions for the job at Payflip (45m, office)

Twin Labs

FOUNDING RUST ENGINEER PARIS OR REMOTE (EUROPE) ABOUT TWIN Twin is building fully autonomous AI agents that run real business operations. You give a goal. Twin figures out the steps. It executes them end-to-end through APIs when they exist and through the browser when they don't. This is not another chatbot. This is not another workflow builder. We are building systems that can operate companies. In the first months of beta, users have already deployed more than 100,000 agents running lead generation, customer support, operations, trading systems, e-commerce workflows, reporting, and entire service businesses. Twin was founded by Hugo Mercier , CEO (founder of Dreem, $60M raised, 150+ employees, acquired) and João Justi, CTO (cryptography, compilers, virtual machines, distributed systems, ex-Zama) but also Julius de Bruijn, creator of Tiberius (3.3M downloads) and Patrick Tourniaire We raised a $10M seed round led by LocalGlobe and are building with a small team of senior engineers. WHY JOIN TWIN? * Work on one of the hardest problems in software: making AI agents reliable enough to run real businesses. * Build from first principles: many of the core abstractions don't exist yet. * Small team, massive ownership: your decisions directly shape the product, architecture, and company. * Rust at the core, product at the center: not infrastructure for infrastructure's sake. * Design systems for both humans and AI agents: a new software paradigm that barely exists today. * Early enough to matter: every engineer has outsized impact on what Twin becomes. WHAT YOU'LL WORK ON Most AI companies are focused on generating text or code. We are focused on making AI systems reliably execute real work. You will work on some of the hardest problems in autonomous agents: * Browser execution at scale * Low-latency communication between agent subsystems * Reliable orchestration of long-running workflows * Memory systems that improve over time * Self-healing execution architectures * Agent infrastructure that survives failures * Product features used directly by customers * Internal systems that AI coding agents can understand, operate and extend Part of the challenge is not simply writing software. The challenge is designing systems that remain understandable and modifiable by AI coding agents themselves. The way we build software internally increasingly assumes that both humans and coding agents will interact with the codebase. WHAT WE'RE LOOKING FOR We're not looking for a "Rust developer". We're looking for engineers who can own problems from idea to production. You should probably have: * Significant production Rust experience * Strong systems thinking * Experience building and operating real products * High autonomy * Ability to navigate ambiguity * Interest in AI systems and LLMs * Curiosity across the entire stack You may come from: * Infrastructure * Databases * Distributed systems * Developer tools * Browsers * Networking * Compilers * Runtime systems * AI infrastructure What matters most is your ability to build robust systems and make good product decisions. WHAT TENDS TO WORK WELL HERE The engineers who thrive at Twin usually: * Ship fast * Take ownership without waiting for permission * Care deeply about product outcomes * Prefer building over discussing * Enjoy working close to users * Can move between infrastructure and product work Many of the strongest engineers we know have backgrounds as founders, open-source maintainers, systems engineers, or product-minded infrastructure builders. WHAT WON'T WORK This role is probably not for you if: * You need detailed specifications before starting * You prefer working on isolated technical components * You only want to work on backend infrastructure * You are uncomfortable making product decisions * You dislike ambiguity * You expect large-company processes EXAMPLES OF BACKGROUNDS WE FIND EXCITING * Engineers who built widely-used open-source infrastructure * Early engineers from highly technical startups * Systems engineers who became product builders * Founders who built technical products from scratch * Developers who combine deep technical expertise with strong product intuition COMPENSATION Package 200 - 250 K We're building for the long term and want people who think like owners. LAST WORDS The software industry spent the last decade building SaaS. The next decade will be about autonomous companies. We believe AI agents will not just assist people. They will operate businesses. If that future sounds inevitable to you, we'd love to talk.