Senior Hardware Engineer

This position is open exclusively for Ukrainian residents within Ukraine (preferably Kyiv or Lviv).

Cossack Labs is a British cybersecurity firm with R&D centres in Ukraine. We solve security challenges in complex security-sensitive systems end-to-end: we deliver R&D, services, developer tools and bespoke solutions addressing practical risks in high-stakes scenarios.

The Infrastructure & Hardware department is seeking an experienced Hardware Engineer to strengthen our experienced and talented team!

We take on mission‑critical projects and invent solutions to problems that have never been solved before. If you thrive on challenges, enjoy exploring the unknown, and are prepared to work diligently and responsibly, we want you on our team. In this role, you will contribute to creating secure, high-stakes products and deliver solutions with meaningful social impact. We solve unconventional problems, so there is a lot of space for creativity during the R&D stage.

What you should bring to the table:

• Strong knowledge of electronics, including the design of digital circuits based on microcontrollers
• Excellent orientation in a modern component base and approaches
• Experience in prototyping electronic devices
• Circuit debugging using special equipment such as logic analysers and oscilloscopes.
• Experience with EDA tools for electronics design (e.g., KiCAD, Altium, Eagle) and preparation of manufacturing documentation
• Knowledge of technical English (reading and writing documentation)
• Strong communication skills are a must — if you can say it clearly, we can build it quickly
• Collaboration skills for effective cooperation with a team of professionals

What will make you stand out?

• Basic skills in mechanical CAD software (Fusion 360, AutoCAD, SolidWorks, OpenSCAD, FreeCAD)
• Ability to solder fine-pitch components (e.g., LQFP with 0.5 mm pitch)
• Firmware debugging using in-circuit debuggers, programmers, or log files
• Practical experience in reverse engineering
• Programming skills
• Experience with version control systems (Git)
• Experience with Linux
• Basic understanding of cybersecurity and/or cryptography

What will you do with all those skills?

• Develop schematics
• Design PCB layouts
• Prototyping and soldering experimental samples and units
• Develop test stands and other additional equipment for research and testing purposes
• Take part in reverse engineering in bounds of security assessments
• Develop technical documentation, including Gerber, BOM, and assembly drawings
• Collaborate with a team of talented engineers when doing everything above

Hiring process:

• Resume review — 5-7 business days
• Questionnaire and your answers review — 3-4 business days
• Test task
• Introduction call with the Head of Infrastructure & Hardware Engineering
• Technical interview with several team members
• Offer discussion
• Years of fantastic collaboration :)

What’s in it for you?

• Competitive compensation with a flexible and clear bonus scheme
• Hybrid work model: This position allows for a combination of in-office and remote work as needed
• Paid vacation (21 business days per calendar year) and sick leave
• Individual development plan based on your preferred growth direction
• We are building solutions on the intersection of technologies: software development, information security, and cloud/on-prem infrastructure engineering. Sometimes, working with unique technologies — we design applied cryptography schemes and techniques and explore novel ways to implement them
• Reasonable time budgets and an attitude to build things well — we prioritise building for decades, rather than just until the next release
• Conferences, books, courses — we encourage learning and sharing within the community. Our team members contribute a lot to talks, workshops, and blog posts