ChainSecurity | Blockchain Security Engineer | Full-time | INTERNS , HYBRID/REMOTE, Zurich, Switzerland | VISA possible | https://chainsecurity.com/

ChainSecurity is a young and innovative cybersecurity company that operates in the blockchain and cryptocurrency space. Our mission is to make the blockchain space secure and trustworthy for people, companies, and governments alike. We are proud of our security experts from the renowned universities ETH Zurich, EPFL Lausanne and others. We are trusted by 100+ blockchain companies and established corporations with security audits and services. We have secured complex systems for top blockchain clients, such as decentralized finance (DeFi) projects, and multinational organizations, such as banks and industrial consortia.

A ChainSecurity Auditor will review the most complex blockchain projects to find vulnerabilities which no-one else can. By using state of the art tools, expert knowledge and a deep understanding of the fundamentals, we secure projects handling billions, often forming the foundation in the new paradigm of an open financial system.

Your Responsibilities:

* Work directly with the developers of the most successful teams in the blockchain industry to audit their code and secure their products

* Contribute to our security tools and create new ones in collaboration with our internal research team

* Conduct security research and publish your findings

Requirements:

* Strong background in software engineering, focused on security relevant areas and most importantly being able to reason about complex code

* Experience with penetration testing, vulnerability scanning, threat modeling or similar is a plus

* Good knowledge of cryptography

* Proficiency with Linux and Git

* Good written communication skills

* Fluent in OOP programming language

Bonus Points:

* Formal Verification, White Box, Vulnerability Scanning

* Solid Blockchain Knowledge

* Consensus Algorithms

Join us here: https://www.chainsecurity.com/jobs/blockchain-security-engin...

Questions about the role? Contact: Email is hidden

Lumin Digital | Senior Site Reliability Engineer | Full-Time | Remote (US) | 170k-200k USD base, plus bonus+equity

Visa Sponsorship is not provided.

At Lumin Digital, we serve digital banking needs for financial institutions of all types and sizes.

The Senior Site Reliability Engineer (SRE) is a developer with a strong operations mindset, responsible for ensuring the reliability, availability, and scalability of Lumin Digital’s applications. This role focuses on eliminating manual tasks through automation, maintaining Service Level Objectives (SLO), and closely collaborating with Software Engineers (SWE) to implement and maintain best practices for large-scale systems.

Our team has historical low voluntary attrition, especially compared to those in our industry. Our teams are happy here.

Benefits include flexible time off, remote from US, office budget, health and wellness stipend, 401K matching, and ongoing education support.

Job posting: https://jobs.lever.co/lumindigital/8a7a9d0c-1a64-48f7-ac2c-d...

Check out our reviews on Glassdoor, they're legit: https://www.glassdoor.com/overview/working-at-lumin-digital-...

Careers page: https://lumindigital.com/careers/

Klara Inc | FreeBSD System Administrator | Remote (EST, CET) | Full-time Contract

Klara Inc. provides development & solutions focused on open source software and the community-driven development of OpenZFS and FreeBSD.

We are looking for a medior sysadmin to join our team:

* Administer and maintain FreeBSD servers across customer and internal environments

* Build, update, create, and repair FreeBSD ports and packages

* Manage ZFS storage systems and support virtualization platforms (e.g., bhyve, Proxmox, KVM)

* Challenging, high-impact projects with global customers

* Remote-first environment with flexible working hours

You can submit an application on our website: https://klarasystems.com/careers/freebsd-medior-system-admin...

Monadical.com | Chief of Staff | Senior Full-Stack Eng. (Quebec) | Full-Time | REMOTE (Canada)

Monadical is a fully remote software consultancy. We're growing fast and running some exciting initiatives right now. Think of us as the kind of place where you get to work on multiple fronts of the AI revolution. We’re looking for driven people who want to take a leading role in shaping a growing company. Our goal is to be a workplace with a strong focus on learning, where client projects provide a base of capital for us to work on dream projects of our own. We have an inclusive and transparent culture with a public company principles handbook.

We’re looking for:

- Senior Full-Stack Engineers in Quebec with strong skills in Python and/or JavaScript, experience in client relations and project management, a good understanding of machine learning systems, particularly LLMs, and strong UI/UX design and user research abilities to help us build more thoughtful AI-powered products. Experience with ML model deployment is a plus.

- A Chief of Staff to partner with our CEO and leadership team. You’ll drive strategic projects, streamline internal projects, and help turn our momentum into sustainable growth. Ideal background: Technical degree + startup/consulting experience. You've scaled teams before and can context-switch between technical discussions and business strategy. Bonus if you've worked at consultancies or agencies.

See the full description and apply here: https://careers.monadical.com/

If you have any questions, drop us an email at apply at monadical dot com

Some perks of working with us include:

• Work from home (we’re fully remote!) • Flexible working hours • Six weeks of paid vacation • Competitive salary • Strong culture emphasis on individual autonomy and impact on company direction

Coder | https://coder.com/ | Multiple roles | Multiple locations | Full-time

Coder is an AI software development company leading the future of autonomous coding. We empower teams to build software faster, more securely, and at scale through the collaboration of AI coding agents and human developers. Our mission is to make agentic AI a safe, trusted, and integral part of every software development lifecycle.

Coder’s self-hosted Cloud Development Environment (CDE) is the foundation for deploying agentic AI in the enterprise. It provides a secure, standardized, and governed workspace to deploy autonomous coding agents alongside human developers, accelerating innovation while maintaining control and compliance. Coder's isolated, policy-driven environments improve productivity, cut cloud costs, and reduce data risks. Developers transition to AI at their own pace using their own tools. Platform and security teams can govern, audit, and manage a great developer experience at scale.

We passed 100k stars on GitHub! https://github.com/coder

All positions are fully remote in the countries listed unless otherwise specified.

[1] Senior Software Engineer, back-end Go (US/Canada)

[2] Senior Software Engineer, AI tools (US/Canada)

[3] Staff Software Engineer, front-end TypeScript/React (US/Canada)

[4] Software Engineering Manager (US/Canada)

[5] Product Engineer, internal tooling (US)

[6] Technical Program Manager - Contractor (US)

[7] Sales Engineer (UK/Ireland/Poland)

[8] Sr. Manager of Solution Engineering (US)

And more! Apply here + job descriptions, salary bands: https://coder.com/careers?utm_source=o2n5ew72wd

Not all of our jobs are listed here. Please note that you must submit an application to be considered for any of our positions.

Category Labs | https://www.category.xyz/ | Remote and NYC | Full Time | $200K USD+ Category Labs (formerly known as Monad Labs) is a team of systems engineers and researchers on a mission to design and build at the frontier of decentralized technology. We strive to design and build step-function improvements over existing blockchain solutions. After raising $225M in series A funding, led by Paradigm, we are growing our team.

Early Career SWE, 2026 Grads (Rust, C/C++): https://jobs.ashbyhq.com/category-labs/0dfdffdf-cefb-48fb-bb...

Senior SWE (Rust, C/C++): https://jobs.ashbyhq.com/category-labs/45f674b2-d904-482e-a5...

Smart Contract Engineer (Solidity): https://jobs.ashbyhq.com/category-labs/776ce314-aa12-471b-92...

Senior Researcher, Systems: https://jobs.ashbyhq.com/category-labs/015934c5-66e5-4042-94...

Common Prefix – Software Engineers / Auditors – Greece – Remote – Full-Time

Common Prefix is a science-first blockchain consulting company. Our vision is to make blockchains usable for mainstream users and everyday people – paying at the supermarket, remittances, moving money across borders, saving, investing – and solving the real problems of usability, scalability, and interoperability that come with it. We're a 30-person team, half scientists (cryptographer PhDs, post-docs, and professors) from renowned universities, half engineers with long web2 experience. A lot of our field is broken and we're trying to make a small contribution in fixing it, by introducing provable security and proper engineering practices across the board. What we're looking for: Software engineers who can solve problems, are smart, get things done, and enjoy working on the bleeding edge, learning about cryptography, and working from first-principles. Auditors who can write and read code, especially low-level cryptographic implementation code (zero knowledge verifiers, signature schemes, etc), consensus (PoW, PoS), or smart contracts (everything DeFi). Tech stack: Doesn't matter, we'll teach you. But we work mostly with Rust. Open roles: * Software Engineer, https://commonprefix.notion.site/sw-folk * Auditor, https://commonprefix.notion.site/auditing-folk We offer: - $80,000–$160,000 / year cash - Local from Athens, Greece, or remote, preferably in Europe - Conference participation in exciting scientific and engineering venues, 2-3 times per year - The opportunity to work and learn from world-class scientists from major universities in the field of blockchains, cryptography, and consensus If you're interested in joining our team, please reach out to careers<at>commonprefix<dot>com with the subject line "HN: <Job Title>".

VDX.tv (http://www.vdx.tv) | Remote Engineers & Developers | Full-time | REMOTE Established company (20+ years) looking for mature generalists to contribute remotely. You can be anywhere in the world so long as you:

● Are self-motivated and can work independently

● Driven to constantly learn and are always searching for the bigger picture

● Strong in clear thinking and written communication

● Have experience with many languages but can be effective in any language

● Appreciate that all mature software solutions accumulate technical debt and understand how to continually reduce debt and complexity

● Understand how to build highly reliable systems and be responsible for taking code to production

● Understand that code simplicity and readability are more important for long term maintainability

● Want to work on challenging problems and impactful work without being micromanaged

We're hiring across disciplines for engineers who work with Unix and have fluent written and spoken English:

● Backend Servers: Strong in C, Concurrency and Distributed Computing

● Backend Servers: Strong in Java

● Infrastructure: Strong in building infrastructure tooling to program infrastructure.

● Frontend: Strong in Javascript, Typescript, React, and advanced UI and browser applications

● Artificial Intelligence: Strong in Neural Networks, AI Workflows, AI Models.

● Product Design: Ability to spec and build out clean UIs and dashboards.

We value people who are generalists and are interested in learning, developing, and applying expertise across multiple areas. Although our core business is in digital video advertising, we do research and development in areas such as programming languages, databases, distributed computing, infrastructure, and ai. We are private, which gives us the freedom to explore many areas without investors and profits being the sole objective.

Full-time only. Remote only. We start out on a full-time trial contract basis for up to 3 months and use this period as an extended work interview for both sides to assess fit for long-term employment.

Please email Email is hidden if this sounds like the right fit for you.

Ditto | Staff Software Engineer, SDKs (Flutter) | Remote (US / UK) | Full-Time

Ditto is redefining how data moves at the edge. Our mission is to make it effortless for developers to build resilient, real-time applications—no matter the network conditions. Whether you’re in a stadium, airplane, or remote base, Ditto’s peer-to-peer sync engine keeps devices connected and data consistent, even offline.

We’re trusted by Chick-fil-A, Delta Airlines, Lufthansa, and have raised $145M+ to power mission-critical systems across aviation, retail, hospitality, defense, and more. We’re a remote-first, globally distributed team building the future of edge connectivity.

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Staff Software Engineer, SDKs (Flutter)

As a Staff Engineer on Ditto’s SDK team, you’ll own the architecture, performance, and developer experience of Ditto’s Flutter SDK—empowering developers to sync data seamlessly across Android, iOS, desktop, and web.

You’ll design idiomatic Dart APIs, build robust native bridges using Dart FFI and platform channels, and set the technical direction for how real-time sync feels for Flutter developers worldwide. Expect to ship production code, shape release automation, and mentor engineers across the mobile org.

If you love designing elegant APIs, profiling cross-platform performance, and crafting tools other engineers love to use, you’ll thrive here.

Apply Here: https://job-boards.greenhouse.io/dittoliveincorporated/jobs/...

Please feel free to reach out on any questions you have about the role.

MixRank (YC S11) | Software Engineers | 100% REMOTE (Global) | Full-Time

MixRank processes petabytes of data every month from web crawling. We have hundreds of customers using our data products including Google, Amazon, Facebook, Intel, and Adobe, across industries including Finance, Recruiting, Sales, Marketing, and Security.

We’re a fully-remote company with a global footprint in over 20 countries. We're growing, profitable, employee-owned, no dependence on outside funding. Applicants from all geographies and backgrounds are welcome.

We are looking for passionate individuals for whom programming is not just a job but it’s something they love to do. We're obsessed with computers, programming, big data, databases, compilers, hardware, math, data science, and the internet. Does this sound like you? Please apply to join our team.

Our code base is very friendly to new contributors. You'll have a fully-functional development environment within hours (fully automated) and be pushing commits on your first day. Deployments to production happen multiple times per day and finish in less than 2 minutes. Effectively all of our codebase is written in Python, Rust, SQL, Javascript/TypeScript, and Nix. The core technologies you'll need familiarity with to be productive are Python, PostgreSQL, Linux, and Git.

We operate at a larger scale than typical startups. We operate two datacenters with high performance servers we've built that are capable of dealing with the volumes of data we process. We've implemented our own distributed file system. We do full-scale web crawls. We download and perform static analysis on the entire universe of Android APKs and iOS IPAs that are published. Unlike a typical startup where you'll spend half of your time in meetings, and the other half fixing bugs from Jira tickets— at MixRank you'll get to challenge yourself with difficult technical problems that will help you to grow as an individual.

We're hiring continuously for the positions below— they aren't singular positions that will close once filled. Our philosophy on hiring is that the candidate is more important than the position. For each new member of the team, we design a custom role and responsibilities that are specialized to their interests. Other companies will come up with a long list of specific requirements for a position with the expectation that you'll exactly replace someone from the team, or that you'll be the perfect tetris piece that satisfies the job requirements decided by a committee. MixRank is more pragmatic: we'll first get excited about having a unique individual on the team, then we'll figure out the best way to accommodate their specific talents.

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Junior Software Engineer - Remote (Global), Full-Time

We're looking for remote junior engineers that have 0-3 years of professional experience in software, and 5+ years of curiosity exploring computers, programming, and technical hobby projects. This is an open-ended entry role with mentorship and diverse opportunities to work on all areas of our product: databases, distributed systems, infrastructure and tooling, data analysis, machine learning, frontend/backend web development, APIs, data mining, data modeling, and more. To stand out, please highlight what makes you unique: passion for computing, curiosity and side projects, work ethic, niche research, etc.

Ideally you've already graduated, but if you still have one or more years left of school, please feel free to apply anyway, and if you're the right fit for the team we'll figure out a way to accommodate your schedule.

https://www.ycombinator.com/companies/mixrank/jobs/fnwsojk-j...

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Software Engineer - Remote (Global), Full-Time

We're hiring generalist software engineers to work on web applications, data mining, machine learning/data science, data transformation/ETL, data modeling, database scaling, infrastructure, devops, and more. We'll cater the role to whatever subset of these areas match your interests.

Beneficial experience includes PostgreSQL, Python, Rust, Linux, TypeScript, Nix, frontend/backend web development, and data mining.

https://www.ycombinator.com/companies/mixrank/jobs/rxqspen-s...

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I’m Kiran, Chief of Staff (CoS) at MixRank, a fully remote data startup building go-to-market intelligence. We’re US-incorporated but hire globally, and we’re bringing on new teammates to join a fast-moving team with real ownership and impact.