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Suppose there exists a new airline named Jetco that flies domestically across North America. Jetco recently had a study commissioned that tested the boarding time of every airline, and it came out that Jetco had the fastest average boarding times of any airline.

What factors could have biased this result, and what would you look into?

What could potentially bias the average boarding time in favor of an airline that only flies domestically?

What could potentially bias the average boarding time in favor of an airline that only flies domestically?

Boarding Times Bias

A new airline came out as the fastest average boarding times compared to other airlines.  What factors could have biased this result and what would you look into?

Statistics

You are testing hundreds of hypotheses with many t-tests. What considerations should be made?

What is a key disadvantage of the F-test when compared to multiple t-tests?

What is a key disadvantage of the F-test when compared to multiple t-tests?

Hundreds of Hypotheses

You are testing hundreds of hypotheses with many t-tests. What considerations should be made?

In an A/B test, how can you check if assignment to the various buckets was truly random?

In an A/B test, which of the following is a common method to determine if the assignment to the test groups was truly random?

In an A/B test, which of the following is a common method to determine if the assignment to the test groups was truly random?

Random Bucketing

A/B Testing & Experimentation

Senior Software Engineer - Commodities TechnologyAbout the Role A household name in the quantitative trading space is seeking a Senior Software Engineer to join its Commodities Technology team. This group is building cloud-native systems that power risk analytics for commodities trading and is leading a multi-year initiative to develop advanced risk platforms, broaden coverage for new asset classes, and support overall business growth.The Senior Software Engineer will design and implement solutions for risk modeling, P&L calculations, stress testing, market data processing, and large-scale data management. This individual will collaborate with stakeholders to deliver high-performance systems in a fast-paced environment.Key Responsibilities<ul><li>Develop distributed systems for risk analytics and data processing.</li><li>Partner with risk and portfolio teams to deliver scalable solutions.</li><li>Automate reporting and enhance workflows through data-driven insights.</li></ul>Required Qualifications<ul><li>4+ years of software development experience in financial services.</li><li>Some exposure to commodities markets, derivatives, and risk analytics.</li><li>Expertise in Python, distributed architecture, and performance optimization.</li><li>Proficiency in SQL, Pandas, REST APIs, and AWS services.</li><li>Familiarity with Kubernetes, Kafka, Redis, MongoDB, and MS SQL.</li><li>Bachelor's or advanced degree in Computer Science or related field.</li></ul>Preferred Skills<ul><li>Experience with firmwide risk systems and energy markets.</li><li>Knowledge of Beacon Platform and Bloomberg/Morningstar data.</li><li>Familiarity with DevOps tools and Agile practices.</li><li>Additional languages (Rust, Java, Scala, C++ or C#) are a plus.</li></ul>

Role: C++ DeveloperLocation: Amsterdam, The NetherlandsMy client, a leading proprietary trading firm founded by experienced high-frequency traders and with presence in 3 continents, is now looking to expand its development team locally.This role will focus specifically on working closely with our traders in assisting in the design and implementation of Options trading strategies.The Candidate:* A desire to join a leading Proprietary trading company and be part of the trading industry. * Experience with contemporary C++ as well as python in a Linux environment;* Extensive experience implementing any asset class in trading strategies. Benefits:* Excellent variable pay based on performance, with a fair bonus-structure awarding company* A dynamic and vibrant team in an informal setting;* A true sense of responsibility in your work backed by trusting colleagues;* Formal training and continuous feedback;* Public transport & health insurance reimbursement.

A leading Investment Management Firm is looking to bring on a Lead Data Engineer to join its team in Tampa, Denver, Memphis, or Southfield. This is an excellent chance to work alongside industry leaders while getting to be both hands on and helping lead the team. Key Responsibilities<ul><li>Project Oversight: Direct end-to-end software development activities, from initial requirements through deployment, ensuring projects meet deadlines and quality standards.</li><li>Database Engineering: Architect and refine SQL queries, stored procedures, and schema designs to maximize efficiency and scalability within Oracle environments.</li><li>Performance Tuning: Evaluate system performance and apply strategies to enhance data storage and retrieval processes.</li><li>Data Processing: Utilize tools like Pandas and Spark for data wrangling, transformation, and analysis.</li><li>Python Solutions: Develop and maintain Python-based applications and automation workflows.</li><li>Pipeline Automation: Implement and manage continuous integration and delivery pipelines using Jenkins and similar technologies to optimize build, test, and release cycles.</li><li>Team Development: Guide and support junior engineers, promoting collaboration and technical growth.</li><li>Technical Documentation: Create and maintain comprehensive documentation for all development initiatives.</li></ul> Core Skills<ul><li>Experience: Over a decade in software engineering, with deep expertise in Python and Oracle database systems.</li><li>Technical Knowledge: Strong command of SQL, Oracle, Python, Spark, Jenkins, Kubernetes, Pandas, and modern CI/CD practices.</li><li>Optimization Expertise: Skilled in database tuning and applying best practices for performance.</li><li>Leadership Ability: Proven track record in managing teams and delivering complex projects.</li><li>Analytical Strength: Exceptional problem-solving capabilities with a data-centric mindset.</li><li>Communication: Clear and effective written and verbal communication skills.</li><li>Education: Bachelor's degree in Computer Science, Engineering, or equivalent professional experience.</li></ul> Preferred Qualifications<ul><li>Certifications: Professional credentials in Oracle, Python, Kubernetes, or CI/CD technologies.</li><li>Agile Background: Hands-on experience with Agile or Scrum frameworks.</li><li>Cloud Platforms: Familiarity with AWS, Azure, or Google Cloud services.</li></ul>

About the Role We are looking for a Senior Software Engineer to design and implement algorithmic trading solutions in a fast-paced environment. This position involves working closely with stakeholders to translate trading objectives into robust technical systems and strategies. You will help shape execution logic and ensure systems operate reliably under real-world conditions.Key Responsibilities<ul><li>Develop and refine algorithmic trading strategies.</li><li>Collaborate with internal teams to understand requirements and deliver effective solutions.</li><li>Lead technical initiatives and contribute to system architecture decisions.</li><li>Troubleshoot complex issues and ensure operational stability.</li><li>Mentor junior engineers and promote best practices.</li></ul>Qualifications<ul><li>5+ years of software engineering experience, preferably in financial or trading systems.</li><li>Strong programming skills in java and python</li><li>Solid understanding of algorithms, data structures, and system design.</li><li>Experience building distributed or high-throughput applications.</li><li>Ability to work collaboratively and communicate technical concepts clearly.</li><li>Bachelor's or Master's degree in Computer Science or related field.</li></ul>

Our client, a leading hedge fund, is looking for a Senior Applied AI Researcher to join their Applied AI team in London. You will be transforming how professionals interact with artificial intelligence in high-performance environments. This team has developed a suite of AI-powered tools, including custom assistants with deep research capabilities, and is focused on building reasoning models and collaborative AI workspace. We are seeking a Senior Research Scientist to contribute to the development of next-generation AI tools that support decision-making and research workflows. You'll work on impactful projects that bring advanced machine learning research into production, directly influencing how users leverage AI in complex domains. This role offers a unique opportunity to push the boundaries of human + AI collaboration. You'll work within a rich ecosystem of data, models, compute resources, and expert users, enabling rigorous experimentation and innovation. Responsibilities <ul><li>Conduct original research in machine learning, particularly in reinforcement learning, agent architectures, and large language models (LLMs)</li><li>Prototype and develop new ML models and algorithms for real-world deployment</li><li>Collaborate with engineering teams to integrate research into production systems</li><li>Design experiments and analyze results to evaluate model performance</li><li>Engage with end-users to align research with practical applications</li><li>Contribute to the research community through publications, presentations, and open-source projects</li><li>Mentor junior researchers and help shape technical strategy</li><li>Participate in the full research lifecycle from ideation to deployment </li></ul>Requirements: <ul><li>PhD in Computer Science, Machine Learning, Statistics, Applied Mathematics, or a related field</li><li>Strong publication record in top-tier conferences (e.g., NeurIPS, ICML, ICLR, ACL, EMNLP)</li><li>2-5 years of post-PhD experience</li><li>Deep expertise in machine learning, with a focus on NLP and reinforcement learning</li><li>Experience developing ML models in Python (PyTorch)</li><li>Proven ability to translate research into scalable, practical solutions</li><li>Experience deploying ML models in production environments</li><li>Familiarity with financial markets or complex decision-making domains</li><li>Knowledge of vector databases, semantic search, or information retrieval systems</li></ul>

A growing multi-strategy hedge fund is seeking Operations Software Engineers to design, build, and maintain technology that supports its revolutionary operational backbone. If you're looking for a highly collaborative role where you'll work alongside some of the brightest minds in the industry, this is the opportunity for you! This team plays a critical role in ensuring smooth trade lifecycle management, reporting, and reconciliation. What You'll Do <ul><li>Develop and maintain systems for trade capture, reconciliation, settlement, risk, treasury, P&L, and regulatory reporting.</li><li>Collaborate with Operations and Finance to automate workflows and reduce errors.</li><li>Build integrations with external systems such as brokers, fund administrators, custodians, and regulatory platforms.</li><li>Make architectural decisions that enable scalability and long-term reliability.</li></ul> What We're Looking For <ul><li>Bachelor's degree in Computer Science, Engineering, or related field.</li><li>2+ years of professional software engineering experience in financial services.</li><li>Strong programming skills in Python.</li><li>Experience with SQL databases and data modeling.</li><li>Familiarity with the trade lifecycle.</li><li>Strong problem-solving skills and attention to data integrity.</li><li>Excellent communication skills. </li></ul> Nice to Have <ul><li>Knowledge of FIX protocols, SWIFT messaging, or regulatory reporting frameworks.</li><li>Experience with cloud platforms (AWS, GCP, Azure).</li><li>Familiarity with data pipelines, scheduling tools, or workflow orchestration.</li></ul>

Our client is a pioneering systematic hedge fund, redefining electronic trading through high-performance, data-driven solutions. As part of their Crypto desk, you'll join a cutting-edge team operating across centralised and decentralised markets, leveraging AI and ML to drive automation, enhance decision-making, and scale a fully automated global trading platform. This is a unique opportunity to work at the intersection of quantitative development, AI, and crypto trading. You'll collaborate with Researchers, Traders, and Engineers to build intelligent systems that power 24/7 trading strategies, with full ownership from design to deployment. Responsibilities<ul><li>Develop and maintain the quant technology stack supporting systematic crypto trading.</li><li>Lead applied AI/ML initiatives, including anomaly detection, LLM integration, and predictive modelling.</li><li>Design and deploy scalable, real-time applications using deep learning and statistical techniques.</li><li>Collaborate with Researchers and Traders to implement and optimise automated trading strategies.</li><li>Integrate alternative datasets and build intelligent data pipelines to support research and execution.</li><li>Monitor and manage the lifecycle of AI-driven systems in production environments.</li></ul> Requirements<ul><li>6+ years of professional software development experience, ideally in a quantitative or trading environment.</li><li>Strong Python programming skills and a solid foundation in statistics and machine learning.</li><li>Proven experience delivering production-grade AI/ML applications, including LLMs and anomaly detection models.</li><li>Familiarity with cloud infrastructure (AWS preferred), container orchestration (Kubernetes), and workflow tools (Airflow, Argo).</li><li>Experience with observability tools (e.g., Grafana, CloudWatch) and RESTful API development.</li></ul>

Question	Topic	Difficulty	Ask Chance
Boarding Times Bias	Statistics	Medium	Very High
Hundreds of Hypotheses	Statistics	Medium	Very High
Random Bucketing	A/B Testing & Experimentation	Medium	Very High

Selby Jennings Interview Questions

Selby Jennings Interview Guides

Selby Jennings Interview Questions

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