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Signify Technology Interview Questions

A/B Testing

Algorithms

Analytics

Machine Learning

Probability

Product Metrics

Python

Statistics

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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?

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

Job Description:Job Title: Staff Software Engineer Job Type: Perm Salary: Very Competitive based on exp. Role Location: On-site; Palo Alto, CA The Company: Series C AI technology company building backend systems that enable clinical and operational tools used by healthcare organizations. The team combines engineering and research expertise to build safe, reliable AI services for use in regulated data environments. The company is focused on practical, production-grade systems rather than research prototypes. Role and Responsibilities:Design and build scalable backend infrastructure to support AI applications used in healthcare environments.Collaborate with ML engineers and scientists to develop high-throughput data pipelines and microservices.Develop APIs and distributed systems that enable secure data retrieval, processing, and model integration.Ensure patient data protection through strong privacy and security measures across systems.Monitor, optimize, and maintain backend performance to meet enterprise reliability standards.Partner with product managers and healthcare teams to translate clinical needs into technical solutions.Mentor junior engineers, fostering technical growth and best practices within the engineering team. Job Requirements: Must Have:7years of experience in backend engineering (Python, Go, or Java).Proven experience building distributed systems (databases, pub/sub, Kafka, Redis).Expertise in cloud platforms (GCP or Azure preferred; AWS acceptable).Proficiency with Docker, Kubernetes, CI/CD, and cloud networking.Strong understanding of SaaS architecture, data modeling, and security/privacy frameworks.Excellent communication and collaboration skills.Ability to work LATAM-based hours aligned with PST. Nice to Have:Familiarity with LLM frameworks (e.g., LangChain) or vector databases for AI/ML workloads.Experience in healthcare or regulated environments (HIPAA familiarity is a plus).Interest in mentorship and architectural decision-making at scale. Accessibility Statement: Read and apply for this role in the way that works for you by using our Recite Me assistive technology tool. Click the circle at the bottom right side of the screen and select your preferences. We make an active choice to be inclusive towards everyone every day.? Please let us know if you require any accessibility adjustments through the application or interview process. Our Commitment to Diversity, Equity, and Inclusion: Signify's mission is to empower every person, regardless of their background or circumstances, with an equitable chance to achieve the careers they deserve. Building a diverse future, one placement at a time. Check out our DE&amp;I page here

Job Description:Job title: Fullstack Engineer Job type: Full-Time Salary: $200,000 Role location: Onsite, Palo Alto, CA (5 days per week) The company: A fast-growing startup at the crossroads of AI and healthcare, this team is building voice-first, safety-driven platforms that make expert-level medical guidance accessible to everyone. Their mission centers on responsible innovation, developing AI products that are not only powerful but trustworthy and compliant with healthcare standards. The company brings together engineers, clinicians, and AI researchers from world-class organizations to create secure, human-centered systems that redefine how patients and providers interact with technology. Role and Responsibilities:Build and scale B2B SaaS products and internal tools using TypeScript/React (frontend) and Python/Flask (backend).Design and maintain RESTful APIs, microservices, and data pipelines supporting intelligent healthcare applications.Collaborate cross-functionally with AI researchers, product managers, designers, and clinicians to deliver safe, performant user experiences.Contribute to mobile functionality using React Native or Flutter (nice-to-have).Review code, promote engineering best practices, and uphold product quality.Participate in agile ceremonies (sprints, stand-ups, retrospectives) and proactively address technical challenges in a fast-paced environment. Job requirements:5years of experience as a fullstack or software engineer.Expert in TypeScript and React for the frontend.Professional experience with Python and Flask for the backend (Ruby or Node acceptable, but Python preferred).Strong knowledge of SQL/PostgreSQL, database schema design, and query optimization.Familiarity with cloud environments (AWS, GCP, or Azure); Terraform experience is a plus.Experience developing RESTful APIs and integrating third-party services.Solid understanding of SaaS architecture, CI/CD workflows, and version control (Git).Strong problem-solving, debugging, and collaboration skills.Comfortable working in a high-ownership, high-impact environment within a Series B startup.Excellent communication skills and ability to work closely with cross-functional teams.Must be onsite full-time in Palo Alto, CA. Nice-to-have:Experience with React Native or Flutter mobile development.Background in healthcare technology, AI integration, or voice/chat interfaces.Familiarity with Flask servers in production and infrastructure automation (Terraform AWS).Prior experience in top engineering companies or universities.

Signify is partnering with a key client on an exciting contract opportunity. Role: Senior Data Engineer (Scala) – initial 6 monthsLocation 1 day a week on-site in LondonRate: 600 OutsideIR35 Interview Process: 3 stages – interview, but can move quickly Key Responsibilities<ul><li>Build and maintain Scala-based data pipelines.</li><li>Develop workflows in Airflow and Databricks.</li><li>Work on streaming data and experimentation platforms.</li><li>Ensure data quality, reliability, and scalability.</li></ul> Requirements<ul><li>5+ years in Data Engineering or Data Platform teams.</li><li>Strong Scala and Spark skills.</li><li>Experience with Airflow, Databricks, and streaming tools (Kafka, Kinesis).</li><li>Background in experimentation or analytics platforms.</li></ul> if you fit the above skills, pleae reach out and submit your cv.

Job Description:Job Title: Staff Software Engineer Job Type: Perm Salary: Very Competitive based on exp. Role Location: On-site; Palo Alto, CA The Company: Series C AI technology company building backend systems that enable clinical and operational tools used by healthcare organizations. The team combines engineering and research expertise to build safe, reliable AI services for use in regulated data environments. The company is focused on practical, production-grade systems rather than research prototypes. Role and Responsibilities:Design and build scalable backend infrastructure to support AI applications used in healthcare environments.Collaborate with ML engineers and scientists to develop high-throughput data pipelines and microservices.Develop APIs and distributed systems that enable secure data retrieval, processing, and model integration.Ensure patient data protection through strong privacy and security measures across systems.Monitor, optimize, and maintain backend performance to meet enterprise reliability standards.Partner with product managers and healthcare teams to translate clinical needs into technical solutions.Mentor junior engineers, fostering technical growth and best practices within the engineering team. Job Requirements: Must Have:7years of experience in backend engineering (Python, Go, or Java).Proven experience building distributed systems (databases, pub/sub, Kafka, Redis).Expertise in cloud platforms (GCP or Azure preferred; AWS acceptable).Proficiency with Docker, Kubernetes, CI/CD, and cloud networking.Strong understanding of SaaS architecture, data modeling, and security/privacy frameworks.Excellent communication and collaboration skills.Ability to work LATAM-based hours aligned with PST. Nice to Have:Familiarity with LLM frameworks (e.g., LangChain) or vector databases for AI/ML workloads.Experience in healthcare or regulated environments (HIPAA familiarity is a plus).Interest in mentorship and architectural decision-making at scale. Accessibility Statement: Read and apply for this role in the way that works for you by using our Recite Me assistive technology tool. Click the circle at the bottom right side of the screen and select your preferences. We make an active choice to be inclusive towards everyone every day.? Please let us know if you require any accessibility adjustments through the application or interview process. Our Commitment to Diversity, Equity, and Inclusion: Signify's mission is to empower every person, regardless of their background or circumstances, with an equitable chance to achieve the careers they deserve. Building a diverse future, one placement at a time. Check out our DE&I page here

Job Title: Senior Engineering Manager Location: London (Hybrid 1-2 days a week in the office) Signify have partnered with a leading organisation in the media and digital content industry, shaping how audiences engage with news, entertainment, and storytelling. Their platforms deliver high quality content to millions of users daily, powered by cutting edge technology and data-driven innovation. They are looking to hire a Senior Engineering Manager with a strong Python background to lead multiple engineering teams, including managers, and to drive excellence, scalability, and innovation across our digital products. As a Senior Engineering Manager, you will oversee a group of engineering managers and their teams, ensuring the delivery of high quality, reliable, and scalable products. You will balance strategic planning, technical mentorship, and organisational leadership, while promoting engineering best practices across the company. You will work closely with Product, Data, and Infrastructure teams to build and evolve the next generation of our media platforms. Key Responsibilities <ul><li>Lead, coach, and develop a group of engineering managers and senior engineers, fostering growth and collaboration. </li><li>Set and drive the technical and architectural vision for Python based systems and services that power our media platforms. </li><li>Partner with Product and Design to align engineering priorities with business objectives. </li><li>Oversee delivery of large scale projects, ensuring quality, timeliness, and scalability. </li><li>Champion engineering excellence, automation, and continuous improvement across teams. </li><li>Manage staffing, performance reviews, and succession planning within the engineering organisation. </li><li>Experience growing teams </li><li>Stakeholder and Vendor Management experience </li><li>Promote a culture of inclusivity, psychological safety, and technical curiosity. </li><li>Stay current with technology trends in Python, media technology, and cloud platforms to guide long-term strategy. </li></ul>Requirements <ul><li>8+ years of software engineering experience, with at least 3–5 years in people management. </li><li>Proven experience managing managers and leading large, multi-disciplinary engineering organisations. </li><li>Strong technical foundation in Python and related frameworks such as Django, Flask, or FastAPI. </li><li>Experience designing and operating scalable, distributed systems. </li><li>Background working in media, content delivery, or streaming platforms is preferred. </li><li>Excellent communication and stakeholder management skills. </li><li>Demonstrated ability to foster innovation, accountability, and a high performance culture.</li></ul>

Senior Java Developer – London (Hybrid: 2 Days Onsite)We’re partnering with a leading global organisation that is scaling its engineering function and looking for a Senior Java Developer to join their London team. If you’re passionate about building data-driven platforms, enjoy solving complex challenges, and want to work with modern cloud-native technologies, this is the role for you. What You’ll Be Doing<ul><li>Designing, developing, and maintaining scalable Java applications using strong OOP principles.</li><li>Playing an active role in requirements gathering and design workshops, contributing ideas and identifying gaps.</li><li>Mentoring and pairing with junior developers to support team growth and best engineering practices.</li><li>Implementing and optimising microservices and distributed systems using GCP technologies (GKE, PubSub, BigQuery, Dataflow).</li><li>Designing and maintaining data processing pipelines across streaming, relational, and NoSQL systems.</li><li>Writing and executing unit, integration, and non-functional tests to uphold high code quality standards.</li><li>Participating in Agile ceremonies, researching new approaches, and contributing to team discussions.</li><li>Supporting CI/CD processes with Jenkins and Git, ensuring smooth deployments and automation.</li><li>Troubleshooting production issues, proposing improvements, and staying ahead of emerging technologies.</li></ul> What You’ll Bring<ul><li>Strong experience in Java and core object-oriented programming.</li><li>Background working with data platforms, streaming technologies, and data processing frameworks.</li><li>Understanding of microservices architecture and distributed systems.</li><li>Exposure to Google Cloud Platform, ideally GKE, PubSub, and BigQuery.</li><li>Experience with relational and/or NoSQL databases.</li><li>Knowledge of Docker, Kubernetes, and cloud-native engineering.</li><li>Solid understanding of Git, CI/CD pipelines, automated testing, and engineering best practices.</li><li>Experience with unit, integration, and performance testing.</li><li>Hands-on use of Jenkins for CI/CD automation.</li><li>Strong problem-solving skills, curiosity, and a proactive mindset.</li><li>Ability to identify improvements and communicate them clearly.</li></ul>

Job title: Fullstack Engineer Job type: Full-Time Salary: $200,000+ Role location: Onsite, Palo Alto, CA (5 days per week) The company: A fast-growing startup at the crossroads of AI and healthcare, this team is building voice-first, safety-driven platforms that make expert-level medical guidance accessible to everyone. Their mission centers on responsible innovation, developing AI products that are not only powerful but trustworthy and compliant with healthcare standards. The company brings together engineers, clinicians, and AI researchers from world-class organizations to create secure, human-centered systems that redefine how patients and providers interact with technology. Role and responsibilities:<ul><li>Build and scale B2B SaaS products and internal tools using TypeScript/React (frontend) and Python/Flask (backend).</li><li>Design and maintain RESTful APIs, microservices, and data pipelines supporting intelligent healthcare applications.</li><li>Collaborate cross-functionally with AI researchers, product managers, designers, and clinicians to deliver safe, performant user experiences.</li><li>Contribute to mobile functionality using React Native or Flutter (nice-to-have).</li><li>Review code, promote engineering best practices, and uphold product quality.</li><li>Participate in agile ceremonies (sprints, stand-ups, retrospectives) and proactively address technical challenges in a fast-paced environment.</li></ul> Job requirements:<ul><li>5+ years of experience as a fullstack or software engineer.</li><li>Expert in TypeScript and React for the frontend.</li><li>Professional experience with Python and Flask for the backend (Ruby or Node acceptable, but Python preferred).</li><li>Strong knowledge of SQL/PostgreSQL, database schema design, and query optimization.</li><li>Familiarity with cloud environments (AWS, GCP, or Azure); Terraform experience is a plus.</li><li>Experience developing RESTful APIs and integrating third-party services.</li><li>Solid understanding of SaaS architecture, CI/CD workflows, and version control (Git).</li><li>Strong problem-solving, debugging, and collaboration skills.</li><li>Comfortable working in a high-ownership, high-impact environment within a Series B startup.</li><li>Excellent communication skills and ability to work closely with cross-functional teams.</li><li>Must be onsite full-time in Palo Alto, CA.</li></ul> Nice-to-have:<ul><li>Experience with React Native or Flutter mobile development.</li><li>Background in healthcare technology, AI integration, or voice/chat interfaces.</li><li>Familiarity with Flask servers in production and infrastructure automation (Terraform + AWS).</li><li>Prior experience in top engineering companies or universities.</li></ul>

Job title: Senior Machine Learning Engineer Job type: Contract Contract Length: 12-24m Rate: €300-330 Role Location: Remote (must be based in Poland) The Company A key player in the insurance space, using AI-powered analytics to support policy generation. A client we are working with are hiring a Senior Machine Learning Engineer to lead the design and development of scalable ML solutions. This is a hands-on engineering role focused on deploying models into production, integrating ML systems, and ensuring performance and reliability across teams. Role & Responsibilities <ul><li>Design, build, and deploy scalable machine learning and deep learning models. </li><li>Integrate ML solutions into production systems using best engineering practices. </li><li>Collaborate with cross-functional teams to ensure model performance, reliability, and maintainability. </li><li>Drive MLOps and CI/CD practices to streamline model lifecycle and deployment. </li><li>Work with cutting-edge technologies including LLMs and Azure AI services. </li><li>Design and implement scalable, secure, and maintainable APIs. </li><li>Proactively identify and resolve production bottlenecks. </li></ul>Requirements <ul><li>3+ years of experience in ML engineering, with a strong focus on deploying models into production. </li><li>Deep technical expertise - this is an engineering role, not a data science role. </li><li>Strong hands-on experience with Azure and cloud-based ML workflows. </li><li>Solid understanding and experience with LLMs and AI agent architectures. </li><li>Proficient in Python, SQL, and PySpark. </li><li>Experience with MLOps, CI/CD pipelines, and modern ML frameworks (e.g., TensorFlow, PyTorch, Scikit-learn). </li><li>Strong problem-solving skills and ability to work independently on complex systems. </li></ul>Accessibility Statement Read and apply for this role in the way that works for you by using our Recite Me assistive technology tool. Click the circle at the bottom right side of the screen and select your preferences. We make an active choice to be inclusive towards everyone every day. Please let us know if you require any accessibility adjustments through the application or interview process. Our Commitment To Diversity, Equity, And Inclusion Signify’s mission is to empower every person, regardless of their background or circumstances, with an equitable chance to achieve the careers they deserve. Building a diverse future, one placement at a time. <a>Check out our DE&I page here</a>

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

Signify Technology Interview Questions

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