Senior Application Security Engineer

black.ai; Auckland; On-site; NZD 140,000 - 200,000; Full time

Benefits offered by this job

Unlimited leave

Wellness days

Personal growth budget

Parental leave

Health insurance

Employee stock ownership

Job summary

Halter in Auckland is seeking a Senior Application Security Engineer to own security across the stack, from mobile code to firmware running on collars, and to support global expansion.

You will define security practices, lead threat modeling, and mentor engineers, operating within a context‑over‑control culture that emphasizes IaC and fast delivery.

Qualifications

• Proven experience in application security and threat modeling.
• Ability to define and evolve security practices across an organization.
• Strong communication and leadership to mentor engineers.

Responsibilities

• Proactively identify, assess, and mitigate security vulnerabilities across systems.
• Define threat models for application and infrastructure security.
• Lead security practices, education, and compliance across the team.
• Write and maintain tooling to address vulnerabilities across the stack.
• Mentor engineers to embed security into workflows.
• Collaborate with domain teams to tackle complex security challenges.
• Drive incident response readiness and post-incident learnings.
• Maintain incident response playbooks and work with third parties.

Skills

Security engineering

Threat modeling

Security practices

Mentorship

Security architecture

Job description

About Halter

At Halter, we’re on a mission to enable farmers and graziers to run the most productive and sustainable operations. Our customers are using Halter to break free from the time-intensive constraints of conventional practices. Imagine watching 500 cattle stand up and walk calmly towards their next break? No quad bikes, no dogs, no fences. Just a group of cattle walking at their own pace. People say it looks like magic. Our customers are revolutionizing grazing with Halter. It's changing lives and transforming an industry. People join Halter to do meaningful work. By joining us you’ll be solving challenging problems within a talented team and a culture built for high performance. Our team out-think, out-work and out-care. We’re committed to delivering real change in the world - this isn’t easy, and in truth, we love that it’s hard.

We’re backed to deliver on a mission that matters by Tier 1 investors including Founders Fund, Bessemer Venture Partners, BOND, DCVC, Blackbird, Promus Ventures, Rocket Lab’s Peter Beck and Icehouse ventures.

To find out more, visit our LinkedIn & Instagram.

About the role

Halter enables farmers to grow and graze more grass through the use of virtual fencing. Every farm is deployed with communication infrastructure and a collar for each animal, which is then paired with a mobile and web application. The result is tens of hours of labour saving per week, improved animal welfare, and increased productivity and sustainability of the land.

To ensure we can keep the system airtight and continue to deliver on this mission we are looking to bring on a Senior Application Security Engineer.

With Halter's system now serving hundreds of thousands of devices in the field, and spanning over 40 engineers across five teams, we need to make sure we have the right ways of working in place to deliver a reliable and secure product as we expand globally.

As the first in this role you have the opportunity to define how we think about and operate application security here at Halter. You will have ownership over everything from security practices, to education of the team, to threat detection, compliance, third‑party assessment, penetration testing, and everything in between.

In this role you will be hands‑on, operating with deep technical expertise, a high level of agency, as well as using strong communication skills. You will work across the entire technical stack, from the mobile code, to our backend systems, all the way to the firmware running on the collar. You can expect a high level of collaboration working as part of our ‘context over control’ culture to introduce best practices that mature our security posture while ensuring we maintain the speed of delivery we value as a company.

As part of this you will work primarily in the AWS ecosystem across a mix of managed and self‑managed services. You will work alongside a small but deeply experienced platform engineering team, all with a strong mindset of IaC, a love for autonomy, and a passion for their craft.

What your day could look like

• Proactively identify, assess, and prioritise security vulnerabilities, threats, and risks across our systems, working to implement effective mitigation strategies.

• Research, define and create threat models that can be used as a cornerstone of preparation in the application and infrastructure security landscape.

• Help define and evolve security practices and standards across the organization, balancing pragmatic risk reduction with the need for developer velocity and operational effectiveness.

• Write and maintain high-quality code and tooling to resolve known security issues and address vulnerabilities across our full engineering stack, from infrastructure to application layers.

• Provide mentorship, guidance, and technical leadership to engineers across the business, ensuring security knowledge and best practices are understood, adopted, and embedded into team workflows.

• Work closely with domain‑specific engineering teams to dive deep into complex security challenges, leading investigations and developing robust solutions that scale.

• Identify, fix, and prevent vulnerabilities across the platform through proactive design reviews, secure coding practices, regular testing, and architecture improvements.

• Drive security incident response readiness, participating in detection, analysis, and resolution of security incidents while embedding learnings into future prevention strategies.

• Help define and maintain security incident response playbooks, to assist in timely and consistent response, using automation to drive efficiency.

• Maintain consistent communication and collaboration with third‑party partners and vendors to ensure we are effectively leveraging external expertise, audits, and tools to meet our security goals.

• Contribute to security education and awareness initiatives, helping foster a strong culture of security across all parts of the organisation.

• Participate in a 24/7 on‑call rotation, providing expert security support during incidents and working to continuously improve our operational response capabilities.

Who we’re looking for

• Extremely motivated, wants their work to matter and is not afraid to push hard to help Halter achieve its mission.

• Loves working as part of a high‑performing team with high ownership and high accountability.

• Prioritises understanding the complexity of the domain and have the ability to build deep empathy with our farmers.

• Deeply experienced in security practices with a love for solving hard problems and the know‑how to securely scale a system to millions of end users.

• Unphased by large codebases and even larger problem spaces.

• Thrives in ambiguity with an ever‑evolving system.

• A strong communicator that defaults to transparency and openness in decision‑making while also being decisive to enable consistent momentum.

• A team player that values collaboration, drives the team’s performance and excels in giving and receiving feedback.

• Understands the importance of the Halter system as part of any farming business and holds the quality bar to 24/7 reliability and availability

Why our team loves working at Halter

At Halter, we’re committed to creating an environment where people thrive. We offer unlimited paid annual leave, as well as additional wellness days. Each year, every team member receives a $1,000 self‑development budget to invest in whatever fuels their personal growth.

We offer six months of fully paid leave for primary caregivers and four weeks of fully paid leave for secondary caregivers, along with a range of additional family‑friendly benefits. To support your wellbeing, we offer subsidised health insurance through Southern Cross.

And finally, everyone at Halter is an owner. Every employee is part of our stock ownership plan; when we succeed, you share in that success.

Our office‑first approach

Being office‑first is a core pillar of our culture. We believe in‑person connections are key to driving your own growth, learning, impact, and building genuine long‑lasting relationships.

We’re office first, not office only. This means that working from the office every day is our default setting, but we flex when needed. Your growth, learning, and impact are truly unlimited here, and a big part of that comes from being together, solving problems, innovating, building context, and constantly learning from each other.

We have a state‑of‑the‑art, dog‑friendly office in the heart of Auckland City and a test farm in Morrinsville. Delicious snacks and drinks are readily available.

About Halter

At Halter, we’re on a mission to enable farmers and graziers to run the most productive and sustainable operations. Our customers are using Halter to break free from the time‑intensive constraints of conventional practices and revolutionizing grazing with Halter. People join Halter to do meaningful work. Our team out‑think, out‑work and out‑care. We’re committed to delivering real change in the world. We’re backed to deliver on a mission that matters by Tier 1 investors including Bessemer Venture Partners, DCVC, BOND, Blackbird, Promus Ventures, Rocket Lab’s Peter Beck and Icehouse ventures.

Join our team

Why our team loves working at Halter:

• Work that genuinely matters. Every now and again a company comes along that transforms an entire industry and leaves the world in a better place. Our team gets to be part of something truly meaningful, helping farmers improve their livelihoods, spend more time with their families, and build more sustainable operations.

• Spectacular people solving hard problems. Our culture is designed for talented people to do work that changes lives. The team is filled with diverse, kind, and driven people who push each other to do their best work. You'll be thrown into the deep end, tackling complex challenges and building something tangible that solves real problems.

• You’ll grow here. Autonomy, mastery, and learning define how we work. You’ll have the freedom to work on interesting problems, master new skills, and continuously develop yourself, both through your role and our $1,000 personal growth fund.

• This isn’t easy, and we love that it's hard. Working at Halter will be the most rewarding and the most challenging work of your life. We move fast, take bold bets, and work hard to reshape an entire industry. As one team member put it: "Joining Halter is a bit like strapping yourself to a rocket ship, but it's an epic journey to be a part of!"\