Security Engineer, Application

Matchbox; Sydney; Hybrid; AUD 180,000 - 250,000; Full time

Job summary

Firmus Technologies in Sydney, Australia, is seeking a Senior Security Engineer to own application security for Firmus AI Cloud and related software. You will implement automation, secure APIs, and enforce tenant isolation across services in a public-cloud, multi-tenant environment.

The role requires hands-on coding in Python/Go/TypeScript and strong experience with OAuth/OIDC/JWT, SBOM, and security design reviews.

Qualifications

• Bachelor's degree in computer science or related field.
• 7+ years in application/product security or security-focused software engineering.
• Experience securing a public cloud or multi-tenant platform with public APIs.
• Knowledge of OWASP Top 10 and OWASP API Security Top 10.

Responsibilities

• Own CI/CD security gates in production (SAST, DAST, SCA, secrets detection, SBOM).
• Lead threat modelling and secure design reviews for multi-tenant services.
• Define authentication, authorization, tenant isolation and secret handling standards.

Skills

CI/CD security

SAST/DAST/SCA

Threat modelling

OAuth/OIDC/JWT

API security

Python/Go/TS

Cloud security

Multi-tenant security

Automation

Education

Bachelor's degree in computer science

Tools

AWS

GCP

Azure

Job description

# Security Engineer, ApplicationFirmus TechnologiesOn-site • Sydney, New South Wales, AustraliaFull-time## Role OverviewFirmus TechnologiesFirmus Technologies is a global leader pioneering the development and operation of efficient AI infrastructure across Asia Pacific.Founded in Australia in 2019, our mission is to create the most efficient AI infrastructure by combining cutting-edge technology with a steadfast commitment to sustainability.At Firmus, we are unique in our approach. We design, build, and operate a new class of digital infrastructure – the AI Factory. Through our model-to-grid technology approach, we have pushed the boundaries of multi-generational liquid cooling systems, energy management, AI software orchestration, and construction. For our customers, this approach allows us to make every watt count and deliver low-cost AI tokens globally.Firmus AI CloudOur large-scale GPU cloud platform, Firmus AI Cloud, is purpose-built to deliver energy-efficient AI compute at scale to customers.It empowers developers, enterprises, educational institutions, and government users to train and deploy AI models with unmatched efficiency and cost savings. With an ever-growing suite of services and applications, we are committed to delivering a cloud experience that is market-leading, proprietary, and built to scale.ROLE SUMMARYFirmus Technologies is seeking a Senior Security Engineer, Application for our Engineering and Technology team. You own application security for Firmus AI Cloud and the internal software that runs it. Automation is how you scale that ownership. Customers provision GPU compute through API and console, software engineers build against it, and our operators run the platform through the same control plane. You own the security of that software: the public APIs, the services behind them, how tenants stay separated inside the application, and the AI assistants and agents we ship on top.KEY RESPONSIBILITIESAutomation and secure delivery* Own the CI/CD security gates that every production repository passes through: SAST, DAST, SCA, secrets detection, and SBOM generation.* Build the systems that do the repeatable work: finding triage, dependency uplift, evidence collection, and draft threat models.* Ship the secure paved roads other teams build on: reusable libraries, service templates, and developer tooling.* Write and review code in the services you protect, including the security-critical paths that tools miss.Security architecture and standards* Set the application security standard and control for authentication, authorisation between services, tenant isolation at the application boundary, secret handling and logging.* Lead threat modelling and secure design review. Define what an attacker can do and what must be true before it ships.* Set the security requirements for the AI assistants and agents we ship e.g. prompt injection, context poisoning.* Govern which tools and tool servers our AI agents and software engineers may reach, and how those integrations are scoped, allow-listed, and audited.Assurance and vulnerability management* Own application security posture across our services: what is covered, what is open, what is accepted with a named owner and an expiry, and what is overdue.* Prioritise fixes on exploitability and exposure alongside CVSS and hold them to the Firmus vulnerability SLAs.* Drive remediation with the teams that own the code so issues close at the source.* Extend SOC 2 Type 2 and ISO 27001 into the software delivery path as services and sites grow. Evidence that a control ran should be a query, not a spreadsheet exercise.Enablement and escalation* Coach security champions inside each team so secure design decisions get made without waiting for you.* Provide application-security expertise during incidents and convert recurring failure modes into gates, tests, standards, or developer tooling.* Give engineering leadership a straight read on application risk and release readiness. Join customer conversations when the question is application security.SKILLS AND EXPERIENCE* Bachelor's degree in computer science or a related technical field.* 7+ years in application security, product security, or software engineering with a security focus.* Experience securing a public cloud or multi-tenant platform with a public API.* Deep, practical knowledge of the OWASP Top 10 and the OWASP API Security Top 10. Has threat modelled multi-tenant APIs in production: identity, authorisation between services, tenant isolation, and the ways a client abuses a published contract using STRIDE or an equivalent method, both for REST and gRPC.* Has improved the security posture of software built by other engineering teams through standards, tooling, review, or secure-by-default patterns.* Has owned CI/CD security gates in production (SAST, DAST, SCA, secrets detection, SBOM) and tuned them to deliver actionable findings with low false-positive rates that engineers trusted and acted upon.* Writes production-quality code in at least one of Python, Go, or TypeScript.* Has replaced manual security work with automation: finding triage, dependency uplift, evidence collection, or regression tests that run without someone watching them.* Hands-on with LLM-backed or agentic features: prompt injection, tool misuse, agent identity and delegated credentials, cross-tenant data leakage, and controls on generated code reaching production. Familiar with OWASP guidance for LLM and agentic applications.* Deep practical experience with OAuth, OIDC, JWT, RBAC or ABAC, application-layer cryptography, token handling, and secrets in software.* Has worked under SOC 2 Type 2 or ISO 27001 and can produce evidence that a control ran.* Willing to join incident response for application and API security.* Willing to travel overseas occasionally when the role requires it.* Clear and effective written and verbal communication in EnglishBonus Points* Experience securing AI agents, sandboxed code execution environments, or systems where AI-generated output can trigger automated actions.* Has run a vulnerability disclosure programme.* Security certifications with application-security depth, such as CSSLP or OSWE.LOCATIONSingapore or Australia## The Team You'll JoinPlatform Engineering