Platform Security Engineer (Senior+) at Complexio

Warsaw, Masovian Voivodeship, Poland -

Full Time

Start Date

Immediate

Expiry Date

06 May, 26

Salary

0.0

Posted On

05 Feb, 26

Experience

5 year(s) or above

Remote Job

Yes

Telecommute

Yes

Sponsor Visa

Skills

Python, Authentication, Authorization, OAuth, JWTs, Data Systems Security, Risk Reasoning, Supply-Chain Security, SAST, SCA, Container Scanning, CI/CD Hardening, Graph Databases, Go, Rust, Pragmatism

Industry

Software Development

Description

We are looking for two Platform Security Engineers (Senior+) to join our Product Security domain. This role exists because the scope and importance of our work has outgrown the capacity of a single person. Our platform underpins multiple products and handles sensitive, high-value data. At its core sits a large, graph-based data store that powers downstream systems. Building and securing access to that data, correctly and pragmatically, is critical to the company. This is a hands-on engineering role. You will design, build, and ship production-grade security and privacy controls, not just define policies or review designs from the sidelines. About the role We are looking for two Platform Security Engineers (Senior+) to join our Product Security domain. This role exists because the scope and importance of our work has outgrown the capacity of a single person. Our platform underpins multiple products and handles sensitive, high-value data. At its core sits a large, graph-based data store that powers downstream systems. Building and securing access to that data, correctly and pragmatically, is critical to the company. This is a hands-on engineering role. You will design, build, and ship production-grade security and privacy controls, not just define policies or review designs from the sidelines Improving and maintaining supply-chain security, including SAST, SCA, container scanning, and CI/CD hardening This role is intentionally broad. You will not be a single-domain specialist, and you will not be shielded from complexity. What success looks like After ~90 days, a successful hire will have: Shipped meaningful, production-level security improvements Taken ownership of parts of the AuthN/AuthZ model and implementation Developed a solid mental model of our data flows and privacy risks Earned trust across teams as someone who can say “this is not okay” — and explain why, with facts Reduced risk in practical ways, not through security theatre How you’ll work This is a high-autonomy role. You are expected to scope problems yourself when needed. You will collaborate closely with engineers across the company, not operate as a silo. Disagreement is normal — decisions should be backed by reasoning, data, and threat modeling, not ego. Blocking a release on security or privacy grounds is possible when warranted, with clear escalation paths. If you see a problem, even outside your direct domain, you are expected to help fix it. What we’re looking for Required Strong proficiency in Python (our primary language) Deep understanding of authentication and authorization concepts, including OAuth, JWTs, permission models, and secure token handling Experience designing and securing non-trivial data systems Ability to reason about risk, trade-offs, and real-world constraints A track record of shipping real security improvements, not just writing policy Strongly preferred Experience with graph databases, ideally Neo4j or similar Experience with CI/CD and supply-chain security (SAST, SCA, container scanning, pipeline hardening) Experience with Go or Rust Some familiarity with frontend or React (not required, but useful for end-to-end thinking) What this role is not Not a policy-only or advisory role Not a role with pre-defined, perfectly scoped tasks Not about chasing tools without understanding the problems they solve Not security theatre If you need everything spelled out, or prefer to avoid ambiguity, this role will be frustrating. Seniority & growth This role is intentionally leveled as Senior+. We are open to hiring at different seniority levels if the fit is right. Titles matter less than ownership, judgment, and impact. Why join You’ll work on core platform security problems that directly affect how data is accessed, protected, and trusted. You’ll have real influence, real responsibility, and the space to do things properly, without losing sight of pragmatism. Join a pioneering joint venture at the intersection of AI and industry transformation. Work with a diverse and collaborative team of experts from various disciplines. Opportunity for professional growth and continuous learning in a dynamic field.

Responsibilities

This hands-on engineering role involves designing, building, and shipping production-grade security and privacy controls for a core platform underpinning multiple products and handling sensitive data. Responsibilities include improving supply-chain security measures like SAST, SCA, container scanning, and CI/CD hardening.