QA Performance Engineer (YouTrack)

Aker Systems

Aker Systems was founded in 2017 by a team of experienced technology professionals who recognised an opportunity to provide highly secure enterprise data platforms to large organisations.  We build and operate ground-breaking, ultra-secure, high performance, cloud-based data infrastructure for the enterprise. Our proprietary technology solutions drive performance and reduce costs while helping our clients to improve the management and sharing of data across their organisations. In 2024, Aker Systems won the Breakthrough Culture Awards highlighting growth companies putting culture first. In 2020 Aker Systems was recognised as a ‘One to Watch’ on the Sunday Times Tech Track.  The Company was also recognised at the Thames Valley Tech Awards 2020; winning the Thames Valley Tech Company of the year, the Emerging Tech Company and High Growth Tech Business categories.  We encourage people of all different backgrounds and identities to apply.  We are committed to maintaining an inclusive, and supportive place for you to do your very best work. About the Role We are seeking a Lead Performance Automation Engineer to define and drive performance engineering strategy, tooling, and practices across large-scale, distributed, cloud-native platforms. This is a technical leadership role responsible for ensuring systems are: * Scalable * Reliable * Resilient under load * Optimised for performance and cost efficiency You will lead performance testing and engineering initiatives across multiple teams, embedding non-functional quality into every stage of the software lifecycle. Key Responsibilities 1. Performance Engineering Strategy & Leadership * Define and own the organisation-wide performance testing and engineering strategy. * Establish standards for: * Performance testing approaches * Workload modelling * Capacity planning * Introduce and scale performance engineering practices across multiple delivery teams. * Provide technical leadership and mentoring to QA and engineering teams on performance best practices. * Align performance goals with business SLAs, SLOs, and user experience expectations. 2. Performance Test Architecture & Automation * Design and implement scalable performance test frameworks and automation pipelines. * Lead adoption of tools such as: * Gatling, JMeter, k6, Locust or similar * Build reusable solutions for: * Load testing * Stress testing * Spike testing * Soak testing * Integrate performance testing into CI/CD pipelines for continuous validation. * Ensure performance tests are repeatable, reliable, and production-representative. 3. Workload Modelling & Test Design * Define realistic user workload models based on production data and usage patterns. * Design performance test scenarios reflecting: * Peak load * Concurrent users * Throughput and latency requirements * Apply risk-based prioritisation for performance testing. * Ensure coverage across: * APIs * Microservices * Data pipelines * Event-driven systems 4. Backend, API & Distributed System Performance * Lead performance validation for: * Microservices architectures * Event-driven systems (Kafka) * High-throughput APIs * Analyse latency, throughput, error rates, and bottlenecks across distributed systems. * Validate system behaviour under failure conditions and degraded environments. * Ensure horizontal scalability and resilience strategies are tested. 5. Cloud, Infrastructure & Scalability Testing * Validate performance across: * AWS cloud environments * Containerised platforms (Docker, Kubernetes) * Conduct capacity planning and infrastructure benchmarking. * Ensure systems scale efficiently using: * Auto-scaling * Load balancing * Distributed architectures * Evaluate performance of Infrastructure as Code (Terraform) deployments. 6. Observability, Analysis & Bottleneck Resolution * Use observability tools to analyse system performance, including: * Metrics (Prometheus, Datadog) * Logs (ELK) * Traces (distributed tracing tools) * Identify and diagnose: * CPU, memory, I/O bottlenecks * Network latency issues * Database performance constraints * Collaborate with engineering teams to optimise system performance and architecture. 7. Non-Functional Quality Governance * Define and enforce performance SLAs, SLOs, and acceptance criteria. * Establish quality gates for performance within CI/CD pipelines. * Ensure performance requirements are validated before production release. * Drive adoption of performance testing standards across teams. * Support audit, compliance, and regulatory expectations in performance-critical systems. 8. Production Performance & Continuous Improvement * Analyse real production performance data to refine testing strategies. * Lead performance-related incident investigations and RCA activities. * Establish feedback loops between production observability and test environments. * Drive improvements in: * System responsiveness * Stability under load * Operational resilience 9. Metrics, Reporting & Optimisation * Define and track performance KPIs, including: * Response times * Throughput * Error rates * Resource utilisation * Build performance dashboards and reporting frameworks. * Drive continuous optimisation initiatives based on performance data. * Align performance metrics with business outcomes and user experience. Technology Environment Performance Testing Tools * Gatling, k6, JMeter, Locust (or similar) Languages * Java, Kotlin, Python, or JavaScript Architecture * Microservices, Event-driven systems, Kafka Cloud & Infrastructure * AWS, Kubernetes, Docker, Terraform CI/CD * GitHub Actions, GitLab CI, Jenkins Observability * Prometheus, Grafana, Datadog, ELK, Distributed Tracing What We’re Looking For Essential * Proven experience as a Performance Test Lead / Performance Engineer / SDET * Strong experience defining performance testing strategies and frameworks * Hands-on expertise with modern performance testing tools * Deep understanding of: * Scalability and distributed system performance * Cloud-native architectures * Experience integrating performance testing into CI/CD pipelines * Strong skills in: * Performance analysis and bottleneck identification * Root cause analysis and system optimisation * Experience defining and tracking performance SLAs/SLOs and KPIs * Ability to lead and influence cross-team quality improvements Desirable * Experience in high-scale or regulated environments * Exposure to: * Chaos engineering * Resilience and fault injection testing * Experience with capacity planning and cost optimisation * Knowledge of security-performance interactions (e.g., encryption overhead) Personal Attributes * Strong systems thinking and analytical mindset * Ability to translate performance data into practical engineering improvements * Influential leader across engineering and product teams * Proactive and outcome-driven * Strong communication and stakeholder management skills Aker Systems Attributes At Aker we work as a team; we are collaborative, hardworking, open, and delivery obsessed. There is no blame culture here: try things, and take responsibility for the outcomes. You are always part of the wider Aker. We help our colleagues and take pride in successfully achieving difficult tasks. We run towards problems and help to solve them. Communicate always, do so accurately and in a timely fashion. In return, we offer a competitive salary, 25 days holiday plus bank holidays, company paid medical insurance and life assurance, pension scheme, annual training allowance, wellbeing allowance, virtual GP, Employee Assistance plan and more. Equal Opportunities Aker Systems fosters a diverse environment that encourages openness in its communications and is committed to providing equal employment opportunity for all people regardless of race, religion, gender or sexual orientation, age, marital status, national origin, citizenship status, disability, veteran status or other personal characteristics. We embrace differences of opinion and diversity because they help challenge us and find new groundbreaking technical solutions.

Proton

Join Proton and build a better internet where privacy is the default At Proton, we believe that privacy is a fundamental human right and the cornerstone of democracy. Since our inception in 2014, founded by a team of scientists from CERN, we have dedicated ourselves to providing free and open-source technology to millions worldwide, ensuring access to privacy, security, and freedom online. Our journey began with Proton Mail, the largest secure email service globally, and has since expanded to include Proton VPN, Proton Calendar, Proton Drive, and Proton Pass. These tools empower individuals and organizations to take control of their personal data, break away from Big Tech’s invasive practices, and defeat censorship. Our work impacts hundreds of millions of lives, from activists on the front lines defending freedom to leaders in governments protecting sensitive information. In some cases, Proton’s services have even been instrumental in saving lives by enabling secure and private communications in high-risk situations. Proton is a profitable company that does not rely upon VC funding, supporting over 100 million user accounts with a growing team of over 500 people from over 50 different countries, from the world's top companies and universities. We value intelligence, learning potential, and ambition in our hiring process. Adaptability is key as we navigate uncharted territories and redefine how business is conducted online. Hiring at Proton is highly selective, with less than 1% of candidates hired. We believe smaller teams of exceptional talent will always prevail over larger teams with lower talent density. You will have the opportunity to work with many of the world's top minds in their fields, ranging from former international math and science olympiad winners to chess champions. We have a global mindset and big ambitions but remain a start-up at heart. We value empowerment and flexibility and keep our structure flat to keep moving fast and avoid unnecessary politics. Tired of blending into the crowd? Join us and do work you can truly be proud of. Check our open-source projects here! The team: Proton VPN enables millions of people to connect securely and privately, even in places where the internet is restricted or unreliable. Delivering that experience means our service must perform flawlessly under highly variable, real-world conditions. We are looking for a Senior Performance Engineer to lead our efforts in making Proton VPN the fastest, most resilient, and most reliable VPN service in the world. You will define and drive the measurement, analysis, and optimization of Proton VPN’s end-to-end performance, across clients, platforms, and global infrastructure. You’ll help ensure that every connection is fast, stable, and private, regardless of where the user is or what network they’re on. What you will do:  * Design and own Proton VPN’s performance framework, defining metrics and KPIs that reflect the real-world experience of users (time-to-connect, throughput, latency, stability, reconnection rates, etc.). * Develop distributed testing systems that simulate real network conditions, including low bandwidth, packet loss, and high-latency scenarios. * Continuously measure and analyze performance across platforms (desktop, mobile, backend) and regions to identify bottlenecks and regressions. * Collaborate with backend, R&D, and client teams to optimize protocol handling, connection setup, routing, and encryption performance. * Create dashboards, reports, and automated alerts to track global performance health. * Contribute to the design of resilient connectivity strategies that adapt dynamically to variable network conditions. * Serve as the performance champion within the engineering organization, mentoring others and driving a data-driven performance culture. Job requirements:  Technical Skills * 5+ years of experience in performance engineering or systems QA, ideally in networking, VPNs, or distributed systems. * Knowledge of network protocols (TCP/IP, UDP, TLS, WireGuard, debugging, manipulating, and performance profiling tools. * Proven ability to analyze latency, throughput, and stability metrics across multiple layers (client, OS, transport, application). * Proficiency in Python (or similar scripting language) * Familiarity with network emulation and simulation tools (e.g., tc/netem, iperf, IPTables/nfTables…). * Experience with monitoring and observability stacks (Grafana, Prometheus, Loki) and CI/CD pipelines. * Cross-platform experience with Linux, macOS, Windows, Android, and iOS preferred. Bonus points for:  * Experience with Rust/C/C++/System development Soft Skills * Analytical and methodical, yet creative in solving complex performance problems. * Comfortable working with uncertainty and non-deterministic conditions. * Collaborative mindset, able to work across client, infrastructure, and data teams. * Strong communication and documentation skills in English.   What We Offer * Office First: Collaboration is easier and more effective in person, which is why we have offices in Geneva, Zurich, Prague, Barcelona, Paris, London, Vilnius, Skopje, and Taipei. You can also enjoy working from home up to 30% of the time, while enjoying great company during our three core days in the office.  * Technology: We provide all the devices and software you need to excel in your role, ensuring you have the best tools at your disposal to achieve your goals. * Food: Lunch and snacks are provided by Proton every day at our offices. * Transport: We will always support our employees with transport costs through subsidizing public transport, bike allowances, or parking spaces based on your office location. * Stock Options: At Proton, we are all owners of the company and you get stock options when you join us. * Flexible Working: You can define your own working hours as long as it works with team meetings. * Learning and Development: We are committed to your professional growth. Proton offers various learning opportunities, including training programs, conferences and events, and continual learning. * Employee Benefits: Comprehensive health insurance plans, competitive retirement savings options, generous vacation and leave policies, and wellness programs. * Work that Matters: Proton is a community-first organization, started with the support of a crowdfunding campaign and built with community input. To this day, Proton’s only source of revenue is user subscriptions. Over 100 million people trust and support Proton, and we put our users and community first in everything we do. Read more about our impact here. Our Commitment to Diversity and Inclusion At Proton, we believe diversity drives innovation and strengthens our mission to provide privacy as a default for all. We are committed to fostering an inclusive environment where all individuals, regardless of race, ethnicity, gender, age, sexual orientation, physical ability, or socio-economic background, feel valued and empowered. We strive to create equal opportunities, promote open dialogue, and support continuous learning to ensure every voice is heard and respected. If you need any extra support or reasonable adjustments during the hiring process, please let your talent partner know. Candidate Privacy Notice When you apply for a position, refer a candidate, or are considered for a role at Proton Technologies AG (Proton, we, us, or our), your information is stored in Greenhouse, in accordance with their Service Privacy Policy. This information is used to evaluate your suitability for the posted position. We also retain this information for consideration for future roles that you may apply for or that we believe may align with your background and skills. If we no longer have a legitimate business need to process your information, we will either delete or anonymize it. Should you have any inquiries about how we use or manage your information, or if you wish to access, correct, or delete your data, please contact our privacy team at careers@proton.ch. Proton does not accept unsolicited resumes from any sources other than directly from candidates. We will not pay a fee for any placement resulting from an unsolicited offer, even if the candidate is subsequently hired by Proton. To learn more about our privacy policy, please visit our privacy policy page.   #LI-Onsite

Graphcore

About Graphcore  At Graphcore, we’re building the future of AI compute.We’re a team of semiconductor, software and AI experts, with deep experience in creating the complete AI compute stack - from silicon and software to infrastructure at datacenter scale.As part of the SoftBank Group, backed by significant long-term investment, we are delivering key technology into the fast-growing SoftBank AI ecosystem.To meet the vast and exciting AI opportunity, Graphcore is expanding its teams around the world.We are bringing together the brightest minds to solve the toughest problems, in a place where everyone has the opportunity to make an impact on the company, our products and the future of artificial intelligence.   Job Summary We decide whether entire racks of machines are good enough to enter production. Our team measures and evaluates large-scale Linux systems—from a single rack to data-centre scale. We don’t just run benchmarks; we determine whether a system behaves correctly, and whether it is reliable enough to be trusted. The work spans designing workloads, building execution systems, and interpreting results. A measurement is only useful if it leads to a decision. You won’t be confined to a narrow role. Some engineers here focus on infrastructure, others on workloads or analysis—but everyone contributes to understanding system behaviour at scale. You are free to specialise, but as a team we are responsible for leaving no gaps. You might find yourself: * Expanding measurement coverage from small clusters to full racks * Designing workloads that expose system behaviour * Building systems to run experiments across large clusters * Interpreting results and defining what “good enough” looks like This is not a pure infrastructure or data role. The work combines systems engineering, measurement, and judgement. We’re looking for engineers who are comfortable working where the right answer isn’t obvious, and where careful measurement matters more than output volume. Selection criteria: Our engineers typically bring significant practical experience and sound engineering judgement. Depth in one area is valued, but the ability to work across boundaries is equally important. Essential * Strong software engineering experience, typically gained across multiple projects or systems over several years * Experience working in Linux-based environments, ideally with distributed or high-performance systems * Proficiency in Python * Experience with automation and CI/CD systems (e.g. GitLab CI, Jenkins, GitHub Actions) * Ability to design, implement, and run experiments or tests that produce meaningful results * Ability to interpret results and communicate findings clearly, with an emphasis on accuracy and usefulness to decision-making * Comfortable working in areas where requirements are not fully defined and judgement is required Desirable * Experience working with large-scale or distributed systems (e.g. clusters, cloud platforms, HPC environments) * Experience with performance, reliability, or systems-level testing/measurement * Familiarity with pytest or similar frameworks for structured test/measurement execution * Experience analysing system behaviour under load (compute, network, or ML workloads) * Experience working with containerisation, orchestration, or provisioning systems (e.g. Docker, Kubernetes, OpenStack) * Proficiency in other applications programming languages (e.g. C++) * Exposure to data analysis, statistics, or interpreting variability in results   Benefits In addition to a competitive salary, Graphcore offers flexible working, a generous annual leave policy, private medical insurance and health cash plan, a dental plan, pension (matched up to 5%), life assurance and income protection. We have a generous parental leave policy and an employee assistance programme (which includes health, mental wellbeing, and bereavement support). We offer a range of healthy food and snacks at our central Bristol office and have our own barista bar! We welcome people of different backgrounds and experiences; we’re committed to building an inclusive work environment that makes Graphcore a great home for everyone. We offer an equal opportunity process and understand that there are visible and invisible differences in all of us. We can provide a flexible approach to interview and encourage you to chat to us if you require any reasonable adjustments.   Sponsorship Applicants for this position must hold the right to work in the UK. Unfortunately at this time, we are unable to provide visa sponsorship or support for visa applications.