Overview About the team Do you enjoy solving problems, writing software, and working with customers? Do you want to join a team where learning about new technology is part of our work every day? Then, come join us! The Industry Solutions Engineering (ISE) team is a global engineering organization that works directly with customers looking to leverage the latest technologies to address their toughest challenges. We work closely with our customers’ engineers to jointly develop code for cloud-based solutions that can accelerate their organization. We work in collaboration with Microsoft product teams, partners, and open-source communities to empower our customers to do more with the cloud. We develop solutions side-by-side with our customers through collaborative innovation to solve their challenges. This work involves the development of broadly applicable, high-impact solution patterns and open-source software assets that contribute to the Microsoft platform. About the role We are hiring a Principal Software Engineer with deep experience and expertise in designing and delivering solutions using modern software engineering practices and cloud technologies. You will be part of a cross-functional team of software engineers, data scientists, technical program managers, and designers who work side-by-side with high-impact and strategic customers and their engineers to build innovative solutions. As part of our team, you will thrive in working with a variety of technologies, not just Microsoft technology. You will solve exciting business problems, contribute to open source, and collaborate with Microsoft product teams. Responsibilities - Partners with appropriate stakeholders to determine user requirements for a set of scenarios. - Leads identification of dependencies and the development of design documents for a product, application, service, or platform. - Leads by example and mentors others to produce extensible and maintainable code used across products. - Leverages subject-matter expertise of cross-product features with appropriate stakeholders (e.g., project managers) to drive multiple group's project plans, release plans, and work items. - Holds accountability as a Designated Responsible Individual (DRI), mentoring engineers across products/solutions, working on-call to monitor system/product/service for degradation, downtime, or interruptions. - Proactively seeks new knowledge and adapts to new trends, technical solutions, and patterns that will improve the availability, reliability, efficiency, observability, and performance of products while also driving consistency in monitoring and operations at scale and shares knowledge with other engineers. Qualifications Minimum qualifications (MQs) - Bachelor's Degree in Computer Science, or related technical discipline AND 9+ years technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or Python - OR 10+ years equivalent experience. Preferred qualifications (PQs) - Master's Degree in Computer Science or related technical field regarded highly - Available for domestic and occaisional international travel (up to 25%) Our team prides itself on embracing a growth mindset, inspiring excellence, and encouraging everyone to share their unique viewpoints and be their authentic selves. Join us and help create life-changing innovations that impact billions around the world! At Microsoft, we are seeking people who have a passion for the positive impact technology can have on communities and for making a difference in the world. Within ISE, you will find a wide range of backgrounds, perspectives, personal and cultural experiences which are vital to our success with our customers.  It’s an informal and flexible work environment and you’ll be welcome to work in the way that best enables you to get your job done. We invest in your health, wellness, and financial future by offering a competitive package including a wide range of benefits built around your personal needs and those close to you.   Benefits/perks listed below may vary depending on the nature of your employment with Microsoft and the country where you work. #ISEngineering #WSS This position will be open for a minimum of 5 days, with applications accepted on an ongoing basis until the position is filled. Microsoft is an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to age, ancestry, citizenship, color, family or medical care leave, gender identity or expression, genetic information, immigration status, marital status, medical condition, national origin, physical or mental disability, political affiliation, protected veteran or military status, race, ethnicity, religion, sex (including pregnancy), sexual orientation, or any other characteristic protected by applicable local laws, regulations and ordinances. If you need assistance with religious accommodations and/or a reasonable accommodation due to a disability during the application process, read more about requesting accommodations.

Req ID: 367052 NTT DATA strives to hire exceptional, innovative and passionate individuals who want to grow with us. If you want to be part of an inclusive, adaptable, and forward-thinking organization, apply now. We are currently seeking a Ontology Expert - Remote to join our team in Dallas, Texas (US-TX), United States (US). Ontology Expert – Healthcare AI Solutions Day to Day job Duties: (what this person will do on a daily/weekly basis) Role Summary We are seeking an experienced Ontology Expert to design, develop, and govern healthcare ontologies that power AI-driven and agentic healthcare solutions. The role focuses on building semantic models that enable interoperability, reasoning, knowledge representation, and explainable AI across clinical and healthcare enterprise systems. Key Responsibilities - Design, build, and maintain healthcare ontologies and semantic models. - Define domain vocabularies, taxonomies, and relationships for AI-driven solutions. - Support knowledge representation for AI agents, decision-support, and clinical intelligence systems. - Collaborate with clinicians, data scientists, and AI engineers to translate knowledge into formal models. - Govern ontology lifecycle, versioning, and semantic consistency. Healthcare Ontology & Semantic Modeling - Develop ontologies using standards such as OWL, RDF, and SKOS. - Work with healthcare standards and terminologies (SNOMED CT, ICD-10, LOINC, RxNorm). - Enable semantic interoperability across EHRs and healthcare data sources. - Support reasoning, inference, and rule-based logic for AI systems. AI & Agentic Solution Support - Enable AI and GenAI systems with structured healthcare knowledge. - Support agentic workflows, decision models, and explainable AI outputs. - Collaborate on RAG pipelines and knowledge graph integration for LLM-based systems. - Ensure semantic accuracy and safety for clinical use cases. Technical Skills & Tools - Strong knowledge of OWL, RDF, SPARQL, and knowledge graph technologies. - Experience with ontology tools such as Protégé, TopBraid, or Stardog. - Familiarity with FHIR, HL7, and healthcare data models. - Exposure to AI/ML and GenAI systems, including LLM-enabled solutions. - Programming or scripting experience in Python or similar languages (preferred). Compliance, Governance & Quality - Ensure ontologies align with clinical safety, regulatory, and compliance requirements. - Support auditability, traceability, and explainability of AI decisions. - Define semantic governance policies and best practices. Basic Qualifications: (what are the skills required to this job with minimum years of experience on each) Required Skills & Experience - 5+ years of experience in ontology engineering, semantic modeling, or knowledge engineering. - Strong healthcare domain knowledge (clinical, payer, or life sciences). - Experience working with structured and unstructured healthcare data. - Ability to collaborate across technical and clinical teams. Nice to Have; Preferred Qualifications - Background in clinical informatics or biomedical informatics. - Experience with healthcare AI platforms or decision-support systems. - Knowledge of semantic search, reasoning engines, or knowledge graphs. - Advanced degree in Computer Science, Biomedical Informatics, or related fields. Soft Skills - Strong analytical and conceptual thinking abilities. - Excellent communication skills to work with clinical and technical stakeholders. - Attention to detail and passion for semantic accuracy. Why Join Us This role offers the opportunity to shape the semantic foundation of AI-driven healthcare solutions, supporting intelligent agents, explainable AI, and interoperable healthcare systems at scale. About NTT DATA NTT DATA is a $30+ billion business and technology services leader, serving 75% of the Fortune Global 100. We are committed to accelerating client success and positively impacting society through responsible innovation. We are one of the world’s leading AI and digital infrastructure providers, with unmatched capabilities in enterprise-scale AI, cloud, security, connectivity, data centers and application services. Our consulting and industry solutions help organizations and society move confidently and sustainably into the digital future. As a Global Top Employer, we have experts in more than 50 countries. We also offer clients access to a robust ecosystem of innovation centers as well as established and start-up partners. NTT DATA is part of NTT Group, which invests over $3 billion each year in R&D. Whenever possible, we hire locally to NTT DATA offices or client sites. This ensures we can provide timely and effective support tailored to each client’s needs. While many positions offer remote or hybrid work options, these arrangements are subject to change based on client requirements. For employees near an NTT DATA office or client site, in-office attendance may be required for meetings or events, depending on business needs. At NTT DATA, we are committed to staying flexible and meeting the evolving needs of both our clients and employees. NTT DATA recruiters will never ask for payment or banking information and will only use @nttdata.com and @talent.nttdataservices.com email addresses. If you are requested to provide payment or disclose banking information, please submit a contact us form, https://us.nttdata.com/en/contact-us. NTT DATA endeavors to make https://us.nttdata.com accessible to any and all users. If you would like to contact us regarding the accessibility of our website or need assistance completing the application process, please contact us at https://us.nttdata.com/en/contact-us. This contact information is for accommodation requests only and cannot be used to inquire about the status of applications. NTT DATA is an equal opportunity employer. Qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability or protected veteran status. For our EEO Policy Statement, please click here. If you'd like more information on your EEO rights under the law, please click here. For Pay Transparency information, please click here. #LI-NorthAmerica

Overview Independently uses artificial intelligence tools and practices across the software development lifecycle. Understands customer/user requirements for a project/sub-section of a product. Leads discussions for the architecture of a solution by testing design hypotheses and developing complex specifications. Independently creates a test strategy that ensures solution quality. Collaborates with internal and external teams to identify dependencies and reach common goals. Writes code that is extensible, maintainable, well-tested, secure, and performant. Uses debugging tools to verify assumptions and improve code quality. Reviews product code to ensure appropriate test coverage and adherence to standards. Proactively drives automation within production deployment across projects. Implements security standards to raise security hardening across solutions, ensuring each layer is independently secure. Responsibilities AI-Native Development Independently uses appropriate artificial intelligence (AI) tools and practices across the software development lifecycle (SDLC) in a disciplined manner. Takes responsibility for the content of their AI-generated requirements, design documents, code, and other assets, assisting other members of the team to do the same. Uses SDLC and engineering health measures (e.g., Accelerate, SPACE framework, Engineering System Success Playbook [ESSP]) to improve processes and practices, especially those involving AI. Experiments with AI tools and practices to improve their own capabilities. Coding Reviews product code and test code to ensure it meets team standards, contains the correct test coverage, and is appropriate for the product or solution area. Brings insight to code reviews to help improve code quality, coaching and providing feedback to develop other engineers' skills. Conducts code reviews in a timely fashion that helps accelerate the pace of development on the team. Considers diagnosability, reliability, testability, and maintainability when reviewing code, and understands when code is ready to be shared or delivered. Applies and reviews for coding patterns, security risks, compliance issues, and best practices in code reviews, providing feedback on code to drive adherence to best practices. Uses automated source code analysis tools that are incorporated into the build/development process. Uses debugging tools, tests, logs, telemetry, and other methods to proactively verify assumptions while developing code before issues occur for products in production. Conducts incident retrospectives to identify root causes of problems, implements repair actions, and identifies mechanisms to prevent incident recurrence. Independently applies least-access principles, uses logging, telemetry, and other appropriate mechanisms to investigate issues while retaining privacy and security, and drives those practices across the team. Leads by example within the team to produce extensible, maintainable, well-tested, secure, and performant code that adheres to design specifications. Continuously improves code performance, testability, maintainability, effectiveness, and cost, while learning about and accounting for relevant trade-offs. Applies metrics to drive code quality and stability. Applies appropriate coding patterns and best practices (e.g., leveraging state-of-the-art generative artificial intelligence [GenAI], approaches to source code organization, naming conventions). Identifies and escalates blockers or unknowns during the development process, communicates how they will impact timelines, and identifies strategies and/or opportunities to address them. Design Independently creates a clear test strategy that ensures solution quality, prevents regression from being introduced into existing code. Ensures test plans incorporate security testing to validate security invariants (including negative cases). Drives adding new tests to cover gaps, deleting or fixing broken tests, and improving the speed, reliability, and defect localization of the test suite. Independently builds testable code and considers testability during design for a project/sub-section of a product/solution. Understands the different types of tests that can be done on a particular system (e.g., unit tests), maintains up-to-date understanding of testing architectures used both across Microsoft and across the industry, and applies them across the architecture as appropriate. Identifies difficult or untestable sections of codes for a project/sub-section of a product/solution for future design or rearchitecture discussions. Leverages artificial intelligence (AI) tools for test automation. Identifies dependencies and incorporates them into the development of design documents for a product, application, service or platform. Actively identifies other teams and technologies to leverage, how they interact, and where their own system or team can support others. Understands upstream and downstream interactions between systems and ensures security, compliance, performance, and reliability can be achieved across the entire stack. Collaborates with other teams to reach common goals where dependencies and validation concerns overlap. Works across teams to resolve conflicts around dependency ownership and required work. Leads discussions for and owns the architecture of a products/solutions and creates proposals for architecture by testing design hypotheses and develop complex design specifications. Tests and explores various design options for a complex product/solution scenario, outlining strengths and weaknesses of each option. Independently collaborates with architects to build and modify complex products/solutions, providing feedback as needed. Owns or collaborates with other engineers on the architecture of solutions, with minimal technical oversight. Develops design documents that support user stories and other product requirements. Maintains awareness of the current technology landscape, and determines how to integrate these technologies within existing systems. Shares learnings and identified solutions from investigations with the team and owns for some design decisions. Ensures system architecture and individual designs meet performance, scalability, resiliency, cost of goods sold (COGS), disaster recovery, and other requirements and expectations. Upholds Microsoft standards of security, privacy, and other compliance requirements and expectations. Understands and coaches less experienced engineers on the importance of building solutions that expand upon the work of others. Drives the refinement of products through data analytics, and makes informed decisions in engineering products through data integration. Reviews designs/architectures within and across teams to provide recommendations for improvements. Engineering Excellence Applies best practices to build code based on well-established methods and secure design principles while also applying best practices for new code development and formal validation of security invariants. Drives product development and scaling to customer requirements and applies best practices for meeting scaling needs and performance expectations and security promises. Considers, identifies requirements for, and drives comprehensive application of automation within production and deployment of a product, targeting zero-touch deployment when possible. Runs code in simulated or other non-production environments to confirm functionality and error-free runtime for products. Drives efforts to ensure the correct processes are followed to achieve a high degree of security, privacy, safety, and accessibility. Creates and assures the presence of visible evidence (e.g., audit trail) to demonstrate compliance for products. Develops and maintains a deep understanding of the implications of onboarding new technologies following expectations of compliance at Microsoft. Demonstrates and maintains an up-to-date understanding of both global and local regulations for technologies and system applications to ensure regulations are followed and met. Works with partner teams to ensure a project/sub-system of a product works well with the components of the partner team, ensuring proper end-to-end testing, live-site coverage, scalability, performance, and DRI escalation pathways are established before going live. Remains current in skills by investing time and effort into being informed of current developments. Proactively seeks new knowledge, evaluating new trends, technical solutions, and patterns, assessing how to adapt them to current problems. Conducts learning and literary sessions to raise awareness on relevant engineering design principles (e.g., security, testability, performance, scalability, accessibility, product knowledge). Uses and enhances, or builds, new software developer tools to support easier, faster, and more effective software engineering for products. Identifies whether open source or internal code is available to address coding needs for a project/sub-system of a product, and reuses it in a responsible manner where applicable. Develops skills in tools outside current areas of expertise. Identifies and/or creates tools that are useful for building the product. Shares best practices and teaches others about new tools and strategies. Understands and applies security best practices and establishes code invariants to model "security as code," ensuring each layer is independently secure, and minimizing risk. Supports and/or adopts security standards for clear security code review practices for a project/sub-system of a product that align with design and engineering principles to raise the security hardening for both protections and detections. Incorporates deployment gates on security controls, and scanners for a project/sub-system of a product to prevent regressions and/or vulnerabilities that would have customer impact. Includes required security monitoring to ensure detection of violations. Independently works with relevant security partners to define security promises and security invariants for the design of a product/solution while factoring in attacker/investigator personas for security monitoring and telemetry needs, ensure threat models and premortems validate upstream and downstream assumptions and security invariants, establish security breach drills and security incident response processes (e.g., impact analysis, containment), and ensure that artificial intelligence (AI) safety features are implemented for the AI production systems tied to a project/sub-system of a product. Implement Leverages their subject-matter expertise to partner with appropriate stakeholders (e.g., technical program managers) to drive a workgroup's project plans, release plans, and work items. Organizes work into smaller sets of tasks as part of an overall roadmap. Guides other members for project estimation and escalates issues that might cause a delay. Ensures required security protections and detection processes are accounted for in planning. Ensures project plans adhere to security, privacy, and compliance requirements. Ensures all code for a product/solution is properly flighted for quicker mitigation of production incidents. Calculates capacity for planning, accounting for appropriate failover and backup/restore mechanisms for disaster recovery for a project/sub-system of a product. Makes considerations for efficient operation of a project/sub-system of a product after it is live. Establishes a rollback plan for a project/sub-system of a product. Leveraging internal experimentation infrastructures, drives experiments that determine the impact of changes, using feature flags/flighting in their code. Collaborates with internal partners (e.g., Data Science, product managers) to incorporate success and guard rail metrics for experimentation. Leverages existing deployment frameworks in the implementation of solutions, automating deployment tasks when possible to ensure efficiency. Follows safe change deployment best practices (e.g., ensuring that flights are set correctly) for their team to minimize adverse impact to users and other services. Ensures that solutions are deployed safely, rolling out security-sensitive features only to applicable, relevant customers and scenarios to reduce the attack surface. Monitors dependency status and ensures that only the latest, secure versions are deployed. Identifies when rollback plans should be enacted for a project/sub-sub-system of a product. Builds deployment infrastructure to allow developers' private builds for a project/sub-sub-system of a product to be tested in a production-like environment. Reliability and Supportability Drives efforts to integrate logging and instrumentation for gathering telemetry data on system behavior such as performance, reliability, availability, usage, and safety mechanisms, and for allowing monitoring and investigating security-related concerns and scenarios for both live and A/B experiments for products, services, and offerings. Leverages telemetry feedback and effectiveness to independently improve subsequent monitoring designs. Classifies and analyzes data on a range of metrics (e.g., health of the system, where bugs may be occurring), and creates outputs (e.g., notifications, dashboards) that improve monitoring and investigating security-related concerns and scenarios, system monitoring and/or issue identification and mitigation. Considers the privacy implications of telemetry code changes, and adding new data points. Acts as a designated responsible individual (DRI) and guides other engineers by developing and following the playbook, working on-call to monitor a system/product/service for degradation, downtime, or interruptions. Alerts stakeholders as to status and initiates actions to restore system/product/service for simple problems and complex problems when appropriate. Responds within service level agreement (SLA) timeframe. Drives efforts to reduce incident volume, looking globally at incidences and providing broad resolutions. Escalates issues to appropriate owners. Maintains operations of live site service, following security best practices when responding quickly to mitigate issues while using the minimum required permissions to do so that arise on a rotational, on-call basis. Implements solutions and mitigations to more complex issues impacting performance or functionality of live site service and escalates appropriately. Reviews and writes incident postmortem and presents insights that drive changes to reduce or eliminate incidents. Independently improves troubleshooting guides (TSGs), wikis, tests, and telemetry to make on-call better, and recommends user-facing support documentation and additional test coverage to reduce likelihood of future user-initiated incidents. Enables secure operations, security monitoring, and integration with live site investigation activities. Identifies and proposes opportunities (e.g., lunch talks, automation, practices, tools) that can be leveraged to improve the live site experience. Adds comprehensive observability and monitoring to services. Understand User Requirements Collaborates with and guides appropriate internal (e.g., product manager, privacy/security subject matter expert, technical lead) and external (e.g. customer escalation team, public forums) stakeholders to determine and confirm customer/user requirements for a project/sub-section of a product/solution. Incorporates customer insights into future designs or solution fixes. Ensures unwritten requirements, such as appropriate continuous feedback loops that measure actionable, quantitative (e.g., customer value, usage patterns, solution performance) and qualitative (e.g., accessibility, globalization) indicators of value are incorporated. Understands, provides feedback on, and advocates for security and privacy needs of the customer who will be using the project/sub-section of a product/solution. Qualifications Required/minimum qualifications Bachelor's Degree in Computer Science or related technical field AND 4+ years technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or Python OR equivalent experience. Additional or preferred qualificationsMaster's Degree in Computer Science or related technical field AND 6+ years technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or Python OR Bachelor's Degree in Computer Science or related technical field AND 8+ years technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or Python OR equivalent experience. Software Engineering IC4 - The typical base pay range for this role across the U.S. is USD $119,800 - $234,700 per year. There is a different range applicable to specific work locations, within the San Francisco Bay area and New York City metropolitan area, and the base pay range for this role in those locations is USD $158,400 - $258,000 per year. Certain roles may be eligible for benefits and other compensation. Find additional benefits and pay information here: https://careers.microsoft.com/us/en/us-corporate-pay This position will be open for a minimum of 5 days, with applications accepted on an ongoing basis until the position is filled. Microsoft is an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to age, ancestry, citizenship, color, family or medical care leave, gender identity or expression, genetic information, immigration status, marital status, medical condition, national origin, physical or mental disability, political affiliation, protected veteran or military status, race, ethnicity, religion, sex (including pregnancy), sexual orientation, or any other characteristic protected by applicable local laws, regulations and ordinances. If you need assistance with religious accommodations and/or a reasonable accommodation due to a disability during the application process, read more about requesting accommodations.

Overview Substrate powers Microsoft 365. Keeping it up, resilient, and continuously improving is core to our mission. The Incident Response SRE team ensures service resilience by preventing outages, accelerating incident resolution, and driving systemic improvements across Substate and MSAI. The team plays a critical role in enabling effective and efficient management of service health for these global scale services. As a Senior Site Reliability Engineer in the Foundation Incident Response team, you will leverage your passion for live site and combine your software engineering with systems engineering knowledge to prevent outages, respond rapidly when they occur, drive learnings, and engineer solutions that eliminate repeat failures. You’ll partner across Substrate and MSAI to raise the reliability bar through data‑driven practices, automation, and blameless retrospectives that translate into durable fixes. Microsoft’s mission is to empower every person and every organization on the planet to achieve more. As employees we come together with a growth mindset, innovate to empower others, and collaborate to realize our shared goals. Each day we build on our values of respect, integrity, and accountability to create a culture of inclusion where everyone can thrive at work and beyond. Responsibilities - Incident management excellence: Lead high-severity incident response, debug complex issues, drive incidents to resolution with clear communication and ownership. Ensure high-quality post mortems reports are created and enforce repair-item SLAs. - Improve observability: Enhance telemetry, alerting, and dashboards using One Microsoft tooling to provide actionable insights and reduce detection time. - Define and measure reliability: Partner with engineering teams to establish and track SLIs/SLOs for critical scenarios. - Live site health reviews: Lead and facilitate live site health review meetings, translating business requirements into metrics and action. - Engineering for prevention: Translate learnings into proactive tests, product fixes, rollout guardrails, and automation that reduce risk and improve service health. - Reliability drills: Design and execute drills to simulate product failures, validate resilience and recovery, and develop resilience strategies. - Define Policy: Draft process and policy documentation for how the organization prepares for, responds to, and prevents incidents. Qualifications Required Qualifications: - Master's Degree in Computer Science, Information Technology, or related field AND 2+ years technical experience in software engineering, network engineering, or systems administration. - OR Bachelor's Degree in Computer Science, Information Technology, or related field AND 4+ years technical experience in software engineering, network engineering, or systems administration. - OR equivalent experience. Preferred Qualifications: - Doctorate Degree in Computer Science, Information Technology, or related field AND 3+ years technical experience in software engineering, network engineering, or systems administration. - OR Master's Degree in Computer Science, Information Technology, or related field AND 6+ years technical experience in software engineering, network engineering, or systems administration. - OR Bachelor's Degree in Computer Science, Information Technology, or related field AND 8+ years technical experience in software engineering, network engineering, or systems administration. - OR equivalent experience. - 3+ years technical experience working with large-scale cloud or distributed systems. #M365CORE Site Reliability Engineering IC4 - The typical base pay range for this role across the U.S. is USD $119,800 - $234,700 per year. There is a different range applicable to specific work locations, within the San Francisco Bay area and New York City metropolitan area, and the base pay range for this role in those locations is USD $158,400 - $258,000 per year. Certain roles may be eligible for benefits and other compensation. Find additional benefits and pay information here: https://careers.microsoft.com/us/en/us-corporate-pay This position will be open for a minimum of 5 days, with applications accepted on an ongoing basis until the position is filled. Microsoft is an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to age, ancestry, citizenship, color, family or medical care leave, gender identity or expression, genetic information, immigration status, marital status, medical condition, national origin, physical or mental disability, political affiliation, protected veteran or military status, race, ethnicity, religion, sex (including pregnancy), sexual orientation, or any other characteristic protected by applicable local laws, regulations and ordinances. If you need assistance with religious accommodations and/or a reasonable accommodation due to a disability during the application process, read more about requesting accommodations.