Cossack Labs provides data security solutions to help innovators protect sensitive data against external attackers, insider threats, and misconfigurations while remaining compliant with regulations.
WHAT WE DO:
We specialize in working with mission-critical, multi-app, multi-platform distributed systems, addressing serious global issues. Our data security solutions cater to large enterprises, startups, and tech-savvy SMEs across various industries, including healthcare, IoT, power grid operators, payment processors, fintech, legal companies, million-user customer applications, decentralized finance systems, AI/ML, and more.
We take on difficult jobs, we take mission-critical software and make it mission-secure.
OUR TEAM:
Operating as a lean core team and a diverse network of experts, we bring together individuals with diverse backgrounds, including PhDs in information security and cryptography, infosec community standard contributors, experts in rare security topics, and business-centric security engineers. Some team members have been in infosec since the 1990s and have witnessed the industry's growth. Others have contributed to writing standards governing security practices.
LEARN WITH US
Explore case studies of our regular work from an engineer’s perspective, read Case Studies: https://www.cossacklabs.com/case-studies/. We are actively involved in cryptographic R&D, maintain free open-source software on GitHub (https://github.com/cossacklabs), share engineering experiences in blog posts, and conferences, and volunteer to help Ukrainian companies enhance security resilience during warfare.
JOIN US FOR A JOURNEY OF GROWTH:
As a Cossack Labs engineer, you will engage in slow-paced projects for learning and improvement, internal projects for innovation and tool-building, and, of course, a few challenges because no smooth sea can make a skilled sailor. Discover what works for you and identify areas for growth. Our core engineers undergo extensive indoctrination and training to become disciplined, stringent, and self-sufficient field units who take ownership of outcomes.
HOW TO APPLY:
Visit our website to learn more about the company and check for current job openings: https://www.cossacklabs.com/job/#open-positions.
WHAT WE DO:
We specialize in working with mission-critical, multi-app, multi-platform distributed systems, addressing serious global issues. Our data security solutions cater to large enterprises, startups, and tech-savvy SMEs across various industries, including healthcare, IoT, power grid operators, payment processors, fintech, legal companies, million-user customer applications, decentralized finance systems, AI/ML, and more.
We take on difficult jobs, we take mission-critical software and make it mission-secure.
OUR TEAM:
Operating as a lean core team and a diverse network of experts, we bring together individuals with diverse backgrounds, including PhDs in information security and cryptography, infosec community standard contributors, experts in rare security topics, and business-centric security engineers. Some team members have been in infosec since the 1990s and have witnessed the industry's growth. Others have contributed to writing standards governing security practices.
LEARN WITH US
Explore case studies of our regular work from an engineer’s perspective, read Case Studies: https://www.cossacklabs.com/case-studies/. We are actively involved in cryptographic R&D, maintain free open-source software on GitHub (https://github.com/cossacklabs), share engineering experiences in blog posts, and conferences, and volunteer to help Ukrainian companies enhance security resilience during warfare.
JOIN US FOR A JOURNEY OF GROWTH:
As a Cossack Labs engineer, you will engage in slow-paced projects for learning and improvement, internal projects for innovation and tool-building, and, of course, a few challenges because no smooth sea can make a skilled sailor. Discover what works for you and identify areas for growth. Our core engineers undergo extensive indoctrination and training to become disciplined, stringent, and self-sufficient field units who take ownership of outcomes.
HOW TO APPLY:
Visit our website to learn more about the company and check for current job openings: https://www.cossacklabs.com/job/#open-positions.
Website:
www.cossacklabs.com
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· 55 views · 3 applications · 24d
Node.js Engineer (with support responsibilities)
Hybrid Remote · Ukraine (Kyiv, Lviv) · Product · 3 years of experience · B1 - IntermediateThis position is open exclusively to Ukrainian residents within Ukraine (preferably Kyiv). We are hiring a Senior Node.js Engineer who will primarily build and evolve our web platform while serving as the first-line responder during business hours,...This position is open exclusively to Ukrainian residents within Ukraine (preferably Kyiv).
We are hiring a Senior Node.js Engineer who will primarily build and evolve our web platform while serving as the first-line responder during business hours, seven days per week. Most days pass without incidents and weekend requests are rare; your time will largely focus on development across Node.js, React, and PostgreSQL.
Support profile:
- Coverage: business hours, seven days per week; weekend requests are rare.
- Expectation: prompt acknowledgment, swift triage, and practical restoration; escalate when needed.
- Reality: frontline duties are light; the majority of your time is dedicated to development.
Main responsibilities:
- Contribute the majority of your time to product development: design, implementation, and testing.
- Deliver high-quality Node.js services and React UI changes; write maintainable, well-tested code.
- Design SQL beyond ORM abstractions; analyze queries, optimize performance, and evolve schemas.
- Improve reliability by creating runbooks, post-incident reviews, and automation for recurring tasks.
- Own rapid first response during business hours via instant messenger and an emergency phone line.
- Triage, reproduce, and diagnose issues across the stack; restore service quickly where possible.
- Apply safe workarounds, configuration tweaks, or hotfixes; execute rollbacks when needed.
- Escalate efficiently to the development team with clear context, logs, impact, and proposed next steps.
- Communicate status and timelines to internal stakeholders and customer contacts.
- Enhance monitoring and alerting; instrument services for actionable logs, metrics, and traces.
Requirements:
- Senior-level experience building production Node.js applications.
- React familiarity for practical UI issues diagnosis.
- PostgreSQL expertise and strong SQL skills beyond ORM usage, including query design and tuning.
- Hands-on experience with incident triage, root-cause analysis, and production debugging.
- Comfortable with Linux servers and on-prem fundamentals (DNS, TLS, certificates, basic networking).
- Proficient with Git workflows and CI/CD practices.
- Familiarity with observability (logs, metrics, traces) and structured troubleshooting.
Nice to have:
- Python or Go experience for tooling, services, or automation.
- Solid understanding of Docker for local development and packaging.
- Knowledge of reverse proxies/load balancers (Nginx, HAProxy, Traefik).
- Exposure to container orchestration (Docker Swarm or Kubernetes) and IaC (Terraform/Ansible).
- Practical experience in diagnosing infrastructure problems: resources congestions, network connectivity issues, PKI and other protocol-level security problems.
- Experience with Sentry, Prometheus/Grafana, ELK/OpenSearch, or OpenTelemetry.
Hiring Process:
- Resume review — up to 5 business days.
- Introductory meeting with the Systems/Software Architect.
- Technical interview with several team members.
- Offer discussion.
We Offer:
- Competitive compensation.
- Hybrid work model: combination of in-office and remote work as needed.
- Paid vacation — 21 business days per year.
- Paid sick leave.
- Exposure to intersecting domains: software development, information security, and cloud/on-prem infrastructure engineering.
- Experience in mission-critical projects.