Job
Description
JLL supports the Whole You, personally and professionally.
Our people at JLL are shaping the future of real estate for a better world by combining world class services, advisory and technology to our clients. We are committed to hiring the best, most talented people in our industry; and we support them through professional growth, flexibility, and personalized benefits to manage life in and outside of work. Whether you’ve got deep experience in commercial real estate, skilled trades, and technology, or you’re looking to apply your relevant experience to a new industry, we empower you to shape a brighter way forward so you can thrive professionally and personally.
Performance Testing Engineer (AI)
JLL | Full-Time
About the Role
JLL is rolling out AI agents, LLM-powered applications, and the platforms behind them across the business. Before they reach thousands of users, they need to prove they are fast, stable, and affordable at scale.
You will own performance engineering for your assigned portfolio of applications and AI systems. The Center of Excellence in our central AI team gives you the methodology, the platform, and the patterns; the business gives you the systems, the SMEs, and the appetite for change. Your job is to design and run load, stress, and resilience tests, find bottlenecks before production does, and turn the results into clear recommendations that teams act on.
We expect engineers at this level to operate with AI tools as a primary part of their workflow. You will use AI to generate test scripts, model realistic workloads, analyze results, and automate reporting. Your leverage comes from the skills, workflows, and automations you build to test safely and repeatedly. The leverage in this role is AI, not headcount.
What You'll Do
Design and run performance, load, stress, soak, and scalability tests for applications, APIs, and data pipelines, in close partnership with developers and business SMEs.
Performance-test AI systems (LLM gateway, shared RAG services, MCP servers, and agents), measuring time to first token, end-to-end latency, throughput, concurrency limits, rate-limit behavior, and token cost per transaction.
Build AI-assisted test automation: use LLMs and agents to generate scripts, create realistic synthetic workloads and data, triage results, and draft reports.
Integrate performance tests into CI/CD pipelines with SLO-based thresholds and gates so regressions are caught before release.
Instrument and monitor systems with observability tooling, diagnose bottlenecks across the application, database, network, and infrastructure layers, and recommend fixes.
Build evaluation harnesses that track AI output quality alongside performance, so speed and cost optimizations do not quietly degrade answers.
Run workshops with engineering and business teams on performance testing practices and on using tools like Claude Code in testing workflows.
Feed benchmarks, patterns, anti-patterns, and platform gaps back into the Center of Excellence so the next engagement moves faster.
Must Have Experience
Hands-on performance testing of production systems using tools such as JMeter, k6, Gatling, or Locust.
Production-quality code in at least one of Python, JavaScript/Node, or Java/.NET, enough to build custom load generators and test automation.
Experience with observability and APM tools (such as Datadog, Dynatrace, New Relic, Grafana, or Azure Monitor) and with analyzing metrics, traces, and logs to find root causes.
Working knowledge of cloud infrastructure (Azure or AWS) and containers, and of how relational, NoSQL, and vector data stores behave under load.
Used AI tools or LLM APIs in real engineering or testing workflows, with a grounded understanding of how LLM systems behave under load: token limits, rate limiting, streaming, caching, and concurrency.
Traits
Strong written and verbal communication; able to explain results and risk to non-engineers.
Pragmatic judgment on what to test, how deep to go, and when results are good enough to ship.
Systems thinking with a focus on failure modes; AI helps write the tests, you own the results.
Comfort running multiple agents and automations in parallel as part of daily workflow.
Why This Role
JLL. A Fortune 200 company and a global leader in commercial real estate, with the stability of a $20B+ business and the resources to invest seriously in AI.
The team. You sit at the seam of the business, product, and engineering, with a direct line into JLL's central AI platform via the Center of Excellence. Your findings are visible from business leadership on down.
The role. The systems you test are the agents and platforms thousands of JLL employees rely on every day, and your work decides whether they hold up at scale. You will see the impact within weeks, not quarters.
If this job description resonates with you, we encourage you to apply, even if you don’t meet all the requirements. We’re interested in getting to know you and what you bring to the table!
At JLL, we harness the power of artificial intelligence (AI) to efficiently accelerate meaningful connections between candidates and opportunities. Using AI capabilities, we analyze your application for relevant skills, experiences, and qualifications to generate valuable insights about how your unique profile aligns with the specific requirements of the role you're pursuing.
If this job description resonates with you, we encourage you to apply even if you don’t meet all of the requirements below. We’re interested in getting to know you and what you bring to the table!
Personalized benefits that support personal well-being and growth:
JLL recognizes the impact that the workplace can have on your wellness, so we offer a supportive culture and comprehensive benefits package that prioritizes mental, physical and emotional health.
About JLL –
We’re JLL—a leading professional services and investment management firm specializing in real estate. We have operations in over 80 countries and a workforce of over 102,000 individuals around the world who help real estate owners, occupiers and investors achieve their business ambitions. As a global Fortune 500 company, we also have an inherent responsibility to drive sustainability and corporate social responsibility. That’s why we’re committed to our purpose to shape the future of real estate for a better world. We’re using the most advanced technology to create rewarding opportunities, amazing spaces and sustainable real estate solutions for our clients, our people, and our communities.
Our core values of teamwork, ethics and excellence are also fundamental to everything we do and we’re honored to be recognized with awards for our success by organizations both globally and locally.
Creating a diverse and inclusive culture where we all feel welcomed, valued and empowered to achieve our full potential is important to who we are today and where we’re headed in the future. And we know that unique backgrounds, experiences and perspectives help us think bigger, spark innovation and succeed together.
