Application security engineers focus on securing software while it is being built. They work alongside developers while products are still being built, looking for weak spots in code, architecture and the way different systems talk to each other. That can mean reviewing a new API, threat-modeling a feature before launch or making sure security checks are built into the development pipeline instead of added after something breaks. Their job is to catch the kinds of flaws that could expose user data to bad actors or turn a routine software update into a security problem.
As companies ship software faster and weave artificial intelligence into everyday products, application security engineers help ensure speed and innovation doesn’t come at the expense of security.
Top Companies Hiring Application Security Engineers
- Amazon
- Microsoft
- OpenAI
- Apple
Top Companies Hiring Application Security Engineers
Headquarters: Redmond, Washington
Founded: 1975
Industry: Enterprise Software, Cloud Computing
What they do: Microsoft secures products used by 430 million people every day, from Windows and Microsoft 365 to Azure and GitHub. Security engineer teams there analyze more than 100 trillion signals daily, offering visibility into one of the largest software ecosystems on the planet. These roles focus on secure software development, identity protection and reducing vulnerabilities before code reaches production.
Headquarters: San Francisco, California
Founded: 2022
Industry: Artificial Intelligence
What they do: Perplexity challenged traditional search engines when it combined web search with generative AI. Its AI-driven platform, which operates as a real-time conversational answer engine, handles more than 780 million queries per month. Application security engineers there focus entirely on securing the high-throughput pipelines that dynamically bridge live web index scraping with advanced large language models.
Headquarters: Cupertino, California
Founded: 1976
Industry: Consumer Technology
What they do: Apple’s reputation is built largely on privacy. Application security engineers here are tasked with safeguarding more than 2.5 billion active devices worldwide. They work across internal development systems, cloud services and operating system components in order to identify vulnerabilities before they can reach customers. Much of that centers on software integrity, secure build pipelines and making sure updates, apps and in-house tools can be trusted inside the tightly controlled ecosystem Apple is known for.
Headquarters: San Francisco, California
Founded: 2015
Industry: Artificial Intelligence
What they do: OpenAI is largely responsible for the generative AI boom thanks to the explosive success of ChatGPT. Its application security engineers help protect the systems behind its API access, account security, product integrations and internal research tools. That work has become more important as OpenAI’s foundation models become widely integrated into business software and consumer products.
Headquarters: Costa Mesa, California
Founded: 2017
Industry: Defense Technology
What they do: Anduril develops autonomous defense systems that combine advanced hardware, sensors and software for military applications. Much of that technology is coordinated through Lattice, the company's AI-powered software platform that helps operators track, analyze and respond to real-time threats. In these roles, application security engineers help make sure software vulnerabilities don’t become real-world liabilities in mission-critical environments.
Headquarters: Santa Clara, California
Founded: 2005
Industry: Cybersecurity
What they do: As the global market leader in cybersecurity by revenue, Palo Alto Networks protects over 80,000 enterprise customers. Application security engineers fortify platforms like Prisma Cloud, Cortex and Strata, doing daily tasks to enhance supply chain security, API integrity and embedding threat-detection controls into high-throughput software pipelines.
Headquarters: Seattle, Washington
Founded: 1994
Industry: Cloud Computing, E-Commerce
What they do: Amazon operates one of the world’s largest software ecosystems through its retail platform, logistics network and Amazon Web Services division. For context, AWS alone controls nearly a third of the global cloud infrastructure market. Open roles frequently highlight secure code review, vulnerability management, threat modeling and protecting large-scale distributed applications.
Headquarters: Austin, Texas
Founded: 2011
Industry: Cybersecurity
What they do: At the heart of CrowdStrike’s operations is the Falcon platform, an AI-powered, single-agent architecture that defends critical infrastructure by processing a trillion security events per day. Application security engineers work with product and cloud-engineering teams to secure the high-throughput pipelines, APIs and lightweight agent code that drive real-time threat telemetry. Their work focuses heavily on kernel-level interface security, cloud-native container defense and building proactive guardrails.
Headquarters: Palo Alto, California
Founded: 2023
Industry: Artificial Intelligence
What they do: Founded by Elon Musk and owned by SpaceX, xAI builds large-scale AI systems like Grok and operates Colossus, a liquid-cooled supercomputer cluster running on 200,000 GPUs. Its application security engineers help protect the software that trains AI models and distributes them across infrastructure, while coordinating one of the biggest computing environments ever assembled for artificial intelligence. Because xAI moves quickly on public-facing AI products, the role can also involve securing real-time data integrations, defending against prompt injection and reducing the ways bad actors could manipulate the AI lifecycle.
Headquarters: Mountain View, California
Founded: 1998
Industry: Internet Services, Cloud Computing, Artificial Intelligence
What they do: Google pioneered many of the secure software practices, like bug bounty programs and zero trust architecture, that are now mainstays throughout the industry. Application security engineers work to protect billions of users across products like Google Cloud, Android, Chrome and Gemini. The company is especially known for advancing vulnerability research, software hardening and large-scale security testing.
