Software Development Engineer III - Amazon Robotics, Autonomous Mobility, AMS Amazon.com Services LLCSoftware Development Engineer III - Amazon Robotics, Autonomous Mobility, AMSNorth Reading, MAThis role offers a unique opportunity to shape the future of autonomous robotics at scale, working with state-of-the-art technologies including real-time robotics systems, machine learning, and agentic AI while seeing your architectural decisions deployed on a production fleet serving millions of customers. • You will play a key role in architecting and implementing next-generation ML and AI-based motion planning and task planning systems, with your work directly impacting thousands of fully autonomous robots operating alongside people in fulfillment centers worldwide.
Optical System Engineer III, Amazon Robotics Amazon.com Services LLCOptical System Engineer III, Amazon RoboticsNorth Reading, MAThis is a senior solo contributor role requiring seasoned judgment, strategic thinking, and the ability to self-guide and take point on complex system-level initiatives—from the first customer conversation through architecture definition to a validated, manufacturable product. This role is the primary technical interface between customers and engineering: - You will oversee customer discovery sessions probing beyond stated needs to uncover latent requirements and translate them into quantifiable design goals.
Sr Electrical Engineer, Amazon Robotics Amazon.com Services LLCSr Electrical Engineer, Amazon RoboticsNorth Reading, MAWe are a smart, collaborative team of enthusiastic doers that work passionately to apply innovative advances in robotics and software to solve real-world challenges that will transform our customers’ experiences in ways we can’t even image yet. The ideal candidate will have extensive experience in system design, analog and digital circuit design, possess good communication skills, and have the ability to lead a team of Electrical Engineers.
Senior AI Engineer - Customer Agent KlaviyoSenior AI Engineer - Customer AgentBoston, MA$148,000–$222,000 / yearIn addition to base salary, our total compensation package may include participation in the company’s annual cash bonus plan, variable compensation (OTE) for sales and customer success roles, equity, sign-on payments, and a comprehensive range of health, welfare, and wellbeing benefits based on eligibility. We have a big opportunity to build state-of-the-art AI and machine learning technologies at Klaviyo to power our products and develop AI agents that can automatically create and execute marketing or customer experiences, strategies, and campaigns for any business.
Senior Software Engineer - Customer Agent KlaviyoSenior Software Engineer - Customer AgentBoston, MA$148,000–$222,000 / yearIn addition to base salary, our total compensation package may include participation in the company’s annual cash bonus plan, variable compensation (OTE) for sales and customer success roles, equity, sign-on payments, and a comprehensive range of health, welfare, and wellbeing benefits based on eligibility. The Customer Agent team is building one of Klaviyo’s most ambitious and strategic product areas: an extensible AI platform that enables brands to deliver personalized, autonomous customer experiences across channels like chat, email, SMS, and beyond.
Senior Full Stack Engineer - Customer Agent KlaviyoSenior Full Stack Engineer - Customer AgentBoston, MA$148,000–$222,000 / yearIn addition to base salary, our total compensation package may include participation in the company’s annual cash bonus plan, variable compensation (OTE) for sales and customer success roles, equity, sign-on payments, and a comprehensive range of health, welfare, and wellbeing benefits based on eligibility. As a Senior Engineer, you’ll tackle complex challenges, develop multiple solutions, and evaluate business and technical trade-offs to determine the best path forward.
Senior Manufacturing Engineer RJS AssociatesSenior Manufacturing EngineerBillerica, MAFull timeManufacturing Engineer will monitor production and testing, assist in troubleshooting manufacturing issues, and drive continuous improvement efforts throughout the process. Manufacturing Engineer your primary responsibility will be to take ownership of one or more product lines and manage that product line’s manufacturing process from beginning to end.
Civil Engineer - Cement expertise JobotCivil Engineer - Cement expertiseFoxborough, MA$80,000–$120,000 / yearInformation collected and processed as part of your Jobot candidate profile, and any job applications, resumes, or other information you choose to submit is subject to Jobot's Privacy Policy, as well as the Jobot California Worker Privacy Notice and Jobot Notice Regarding Automated Employment Decision Tools which are available at jobot.com/legal. The successful candidate will have a proven track record in optimizing existing customer relationships, staying on top of industry trends, collaboration, account management, documentation, sales, mix design, and concrete.
Senior Mechanical Engineer SymboticSenior Mechanical EngineerBrighton, MAApplying next-gen technology, high-density storage and machine learning to solve today's complex distribution challenges, Symbotic enables companies to move goods with unmatched speed, agility, accuracy and efficiency. Cross-Functional Collaboration: Work closely with electrical, software, controls, manufacturing, and quality engineering teams to ensure seamless integration and product success. .
Controls Engineer- Building Automation JobotControls Engineer- Building AutomationBoston, MA$90,000–$120,000 / yearAbout the Role: We’re seeking a Building Controls Engineer to support the design, programming, commissioning, and ongoing support of building automation systems (BAS) for commercial clients in the Boston area. Information collected and processed as part of your Jobot candidate profile, and any job applications, resumes, or other information you choose to submit is subject to Jobot's Privacy Policy, as well as the Jobot California Worker Privacy Notice and Jobot Notice Regarding Automated Employment Decision Tools which are available at jobot.com/legal.
MS Azure Engineer Continental ResourcesMS Azure EngineerBedford, MAFull timeA successful candidate has strong experience with Azure Cloud services, is self-driven, enjoys learning new technologies, and is willing to stretch themselves to become a stronger engineer and mentor others around them to do the same. Developing effective cloud infrastructure, enforcing good architectural principles, providing technical oversight, and ensuring security best practices are implemented and followed.
NewApplication Engineer GCR Professional ServicesApplication EngineerBillerica, Massachusetts$95,000–$130,000 / yearJob Summary: This role is responsible for translating customer technical requirements into product specifications, designing and validating new features, and developing custom mechanical components. It also includes maintaining technical documentation, providing on-site support, and collaborating cross-functionally to ensure successful product implementation.
Lead Firmware Engineer GCR Professional ServicesLead Firmware EngineerWoburn, MassachusettsContractorOur clients System Development Division (SDD) is focused on delivering National Defense capabilities by driving mission-focused strategies to develop advanced technology systems enabling enduring products and solutions focused on achieving the customer vision. Applicants are expected to be self-motivated, detail oriented and have a demonstrated ability to effectively communicate with all levels of management and individual contributors on the program team through strong written and verbal communication skills.?.
Principal Analog Mixed Signal ASIC Layout Engineer GCR Professional ServicesPrincipal Analog Mixed Signal ASIC Layout EngineerCambridge, MassachusettsRemoteContractorA successful candidate will assist ASIC development through creating custom analog layouts, floor planning entire chips, high level problem solving, and executing tape outs. ¿ Perform or guide physical layout, including floor-planning, and simulate circuits using extracted parasitic, contribute to design-for-test development.
NewRF Engineer Butler America AerospaceRF EngineerMaynard, MA$82–$97 / hourContractorExpertise with RF subsystems and hardware including antennas, transmitters, receivers, microwave components, low noise amplifiers, high power amplifiers, advanced electronic modules, amplifiers, mixers, switches, frequency generation circuits, and frequency conversion circuits is desired. -The engineering will collaborate with other engineering disciplines including hardware engineers, systems engineers, and circuit design engineers as well as technical and manufacturing support personnel.
CAD / PCB Engineer II GCR Professional ServicesCAD / PCB Engineer IIAndover, MassachusettsContractorJoin a focused team of engineers bringing highly complex, dense, rugged and secure electronic packaging solutions to our nation’s warfighters and first responders. • Ability to work in a fast-paced engineering services group supporting multiple time zones within the US and internationally.
NewRF Engineer PlanIT GroupRF EngineerChelmsford, MAExpertise with RF subsystems and hardware including antennas, transmitters, receivers, microwave components, low noise amplifiers, high power amplifiers, advanced electronic modules, amplifiers, mixers, switches, frequency generation circuits, and frequency conversion circuits is desired. Basic Minimum Requirements: • Bachelor of Science Degree in Electrical Engineering preferred or BS Degree in Science, Technology, Engineering, or Math (STEM) accepted plus a minimum of 5+ years of relevant professional engineering experience.
General/Interdisciplinary Engineer, Senior - Secret DCS CorporationGeneral/Interdisciplinary Engineer, Senior - SecretBedford, MA$90,220–$170,000 / yearConduct systems architectural analyses to include system design/design feasibility and state-of-the-art assessment to Produce architectures, document planned and existing systems, determine deficiencies, develop alternatives, recommend solutions, and support development of a plan to implement the chosen solution per acquisition and sustainment system engineering processes. Analysis of Alternatives (AoA), Systems Engineering Plan (SEP)…), systems review and analysis with written reporting, briefing, and artifact development as required for all of the technical specialty areas defined in this section; and the planning and execution of all necessary technical reviews, assessments, and interchange meetings (e.g.
Principal Radar Systems Engineer GCR Professional ServicesPrincipal Radar Systems EngineerWoburn, MassachusettsContractorClient is focused on delivering National Defense capabilities by driving mission-focused strategies to develop advanced technology systems enabling enduring products and solutions focused on achieving the customer vision. Applicants are expected to be self-motivated, detail oriented and have a demonstrated ability to effectively communicate with all levels of management and individual contributors on the program team through strong written and verbal communication skills.
Senior Staff Software Engineer, Autonomous Pilot Integration Shield AISenior Staff Software Engineer, Autonomous Pilot IntegrationBoston, MAHardware/Software Debugging — Diagnose and resolve integration issues across complex autonomy stacks, payload computers, and embedded systems in lab and field environments — including memory, CPU, and timing profiling under operationally-representative loads. In this role, youll write new autonomy code — such as mission behaviors, platform-specific control, multi-agent coordination, contingencies, and executive autonomy — and own it end-to-end from software-in-the-loop, to hardware-in-the-loop, to vehicle-in-the-loop, to live test exercise.
Sr. Product Engineer – Web Services EsriSr. Product Engineer – Web ServicesBoston, MARemote$93,600–$159,328 / yearExperience working with ArcGIS applications and technologies (such as ArcGIS Hub, ArcGIS Map Viewer, ArcGIS REST APIs, ArcGIS API for Python, ArcGIS Maps SDKs). You will act as a service owner and trusted decision‑maker, shaping priorities, balancing tradeoffs, and ensuring our web services remain reliable, scalable, and valuable to customers over time.
Staff Machine Learning Engineer SamsaraStaff Machine Learning EngineerBoston, MARemoteYou believe customers are more than a number: Samsara engineers enjoy a rare closeness to the end user and you will have the opportunity to participate in customer interviews, collaborate with customer success and product managers, and use metrics to ensure our work is translating into better customer outcomes. • You want to impact the industries that run our world: The software, firmware, and hardware you build will result in real-world impact—helping to keep the lights on, get food into grocery stores, and most importantly, ensure workers return home safely.
Senior Lead AI Software Engineer KlaviyoSenior Lead AI Software EngineerBoston, MA$216,000–$324,000 / yearAs a Senior Lead Software Engineer on Amplify, you will: Independently own and drive high-impact objectives that span multiple Amplify teams and align with company priorities, defining the technical roadmap that ensures our internal applications, APIs, data and event pipelines, and AI-powered workflows can scale with Klaviyo and continue delivering measurable business outcomes. Independently lead the end-to-end lifecycle of large, multi-team initiatives with clear technical direction, architectural leadership, and active workstream curation, from discovery and design through implementation, rollout, and long-term ownership of complex programs that span internal customers across the company.
for Desktop Support Engineer (Window 11 Upgrade) Tanisha Systemsfor Desktop Support Engineer (Window 11 Upgrade)Plymouth, MAContractorRequired Technical and Professional Expertise: 6 + years’ experience customer service and support of Windows Operating systems in a global enterprise environment from both software and hardware troubleshooting standpoint. Monitor and analyse gaps building processes to rationalize, troubleshoot and escalate technical problems with endpoint management clients, client inventory, application deployments and security patching.
Senior Software Engineer - Route Execution SamsaraSenior Software Engineer - Route ExecutionBoston, MARemoteYou believe customers are more than a number: Samsara engineers enjoy a rare closeness to the end user and you will have the opportunity to participate in customer interviews, collaborate with customer success and product managers, and use metrics to ensure our work is translating into better customer outcomes. • You want to impact the industries that run our world: The software, firmware, and hardware you build will result in real-world impact—helping to keep the lights on, get food into grocery stores, and most importantly, ensure workers return home safely.
Product Engineer II – Utility Solutions EsriProduct Engineer II – Utility SolutionsBoston, MARemote$79,664–$133,120 / yearAs the Product Engineer II – Utilities, you will collaborate with customers, industry teams, and other product development team members to design, develop, and support the right geospatial solutions for electric, gas, water, sewer, stormwater and telecommunications agencies. Design and author test cases for functionality, performance, scalability, and durability; execute both manual and automated tests, analyze test results, and report results.
NewTest Engineer, Senior - Secret DCS CorporationTest Engineer, Senior - SecretBedford, MA$90,220–$165,000 / yearThe Electronic Systems System (ESS) Division aka Force Protection Division's mission responsibility is to manage and execute the modernization, design, development, testing, fielding, and sustainment of the various software and hardware within the ESS Portfolio. Evaluate test environments to ensure they are properly configured and capable of supporting software release testing, including fault insertion and fault identification activities.
NewCybersecurity Engineer DCS CorporationCybersecurity EngineerBedford, MA$90,220–$175,000 / yearUnder the Department of the Air Force Program Executive Office for Command, Control, Communication, and Battle Management (DAF PEO C3BM), Kessel Run technologies make up the DAF BATTLE NETWORK, the systems-of-systems designed to help the Joint Force make operational decisions faster than our adversaries. The Assured Compliance Assessment Solution (ACAS) Cybersecurity Engineer will be a member of the Air Operation Center (AOC) cybersecurity team and will be responsible for assisting with the implementation, maintenance, and operation of the Assured Compliance Assessment Solution (ACAS) suite of tools.
NewSystems Engineer, Principal - TS DCS CorporationSystems Engineer, Principal - TSBedford, MA$123,639–$194,000 / yearC3BM’s main efforts are Architecture and Systems Engineering (ASE), Operational Response Team (ORT), and multiple mission integration teams such as Air, Maritime, and multiple acquisitions consisting of both the Advanced Battle Management System (ABMS) and Space. The MIT is responsible for translating operational requirements into technical solutions, developing integrated architecture, assessing risks, supporting acquisition execution strategies, and coordinating test and evaluation activities to ensure capabilities are delivered to operational users.
NewSystems Engineer, Junior - TS DCS CorporationSystems Engineer, Junior - TSBedford, MA$73,160–$115,000 / yearThe C2ISR Division provides worldwide life cycle support across the spectrum of the C2ISR capabilities based enterprise; including supply, distribution, materiel management, acquisition, system engineering and maintenance, financial planning and budgeting, security, flight test, and contracting functions. Experienced in requirements development, production and deployment, and operation and support, architectures development & implementation, modeling & simulation including but not limited to Model Based Systems Engineering principles, verification & validation, technical data package development and sustainment, and principles of configuration management.
NewSystems Engineer, Senior - TS DCS CorporationSystems Engineer, Senior - TSBedford, MA$90,220–$175,000 / yearThe MIT is responsible for translating operational requirements into technical solutions, developing integrated architectures, assessing and mitigating risks, supporting acquisition execution strategies, and coordinating test and evaluation activities to ensure capabilities are delivered to operational users. C3BM’s main efforts are Architecture and Systems Engineering (ASE), Operational Response Team (ORT), and multiple mission integration teams such as Air, Maritime, and multiple acquisitions consisting of both the Advanced Battle Management System (ABMS) and Space.
AI Engineer SamsaraAI EngineerBoston, MAYou will collaborate with architects, engineers, and cross-functional stakeholders across Samsara to brainstorm, design, rapidly prototype, and productionalize AI-driven features and capabilities that integrate deeply into real business workflows. Samsara (NYSE: IOT) is the pioneer of the Connected Operations™ Cloud, which is a platform that enables organizations that depend on physical operations to harness Internet of Things (IoT) data to develop actionable insights and improve their operations.
Principal Pricing Data Engineer Waters CorporationPrincipal Pricing Data EngineerMilford, MAStrong business domain knowledge and experience working with enterprise systems such as SAP (e.g., supply chain data, orders, revenue recognition, pricing), Salesforce (commercial operations), and/or Service Excellence domains, with the ability to translate business processes into scalable data solutions. You will serve as a key problem solver for complex pricing data challenges and a trusted partner to both technical and business stakeholders, ensuring pricing data is accurate, accessible, and actionable across the enterprise.
Cybersecurity Engineer, Journeyman - Secret DCS CorporationCybersecurity Engineer, Journeyman - SecretBedford, MA$90,220–$185,000 / yearAssist in the development of security documentation including System Security Management Plans, Program Protection Plans, Security Risk Analyses, OPSEC Plans, and other required system security engineering artifacts. The Electronic Systems System (ESS) Division aka Force Protection Division's mission responsibility is to manage and execute the modernization, design, development, testing, fielding, and sustainment of the various software and hardware within the ESS Portfolio.
NewSystems Engineer, Journeyman DCS CorporationSystems Engineer, JourneymanBedford, MA$96,757–$145,000 / yearThe MIT is responsible for translating operational requirements into technical solutions, developing integrated architectures, assessing and mitigating risks, supporting acquisition execution strategies, and coordinating test and evaluation activities to ensure capabilities are delivered to operational users. C3BM’s main efforts are Architecture and Systems Engineering (ASE), Operational Response Team (ORT), and multiple mission integration teams such as Air, Maritime, and multiple acquisitions consisting of both the Advanced Battle Management System (ABMS) and Space.
Senior Data Engineer Waters CorporationSenior Data EngineerMilford, MAWe collaborate with customers around the world to advance the release of effective, high-quality medicines, ensure the safety of food and water, and drive better patient outcomes by detecting diseases earlier, managing routine infections, and combating antibiotic resistance. The Senior Data Engineer is a hands on contributor responsible for building, maintaining, and improving data pipelines and data assets that support analytics, machine learning, and operational reporting.
NewSystem Integration Engineer - Remote Teoresi GroupSystem Integration Engineer - RemoteBoston, MARemoteAt Teoresi, we specialize in supporting companies in creating projects using cutting-edge technologies such as self-driving cars and nanotechnology for the medical field. Teoresi Inc is an international Group, with offices in Europe and United States, that acts as an engineering partner to customers’ product and process development.
NewRailway Engineer - Remote Teoresi GroupRailway Engineer - RemoteBoston, MARemoteIntegration of onboard and wayside subsystems, including signaling components, sensors, communication interfaces, and control units, into system-level testing environments (e.g., HIL/SIL). At Teoresi, we specialize in supporting companies in creating projects using cutting-edge technologies such as self-driving cars and nanotechnology for the medical field.
NewDistribution Engineer LeidosDistribution EngineerPawtucket, RI$59,150–$106,925As a valued team member, you can look forward to a fast paced, diverse work environment and flexible work hours/work arrangements, as well as managers who will encourage career development and growth opportunities, including Professional Engineer License (PE) , Project Management Professional (PMP) , Leadership training, Formal Mentorship Programs, Management opportunities. Gain experience in coordinating conflicting utilities and other field engineering design requirements, assessing and developing large design packages for complex cable/conduit projects in dense urban environments, work permit development, easements, and ROW applications.
Software Engineer II - Inline Mailflow AbnormalSoftware Engineer II - Inline MailflowBoston, MADesign and implement core components of the SMTP relay harness, including Mail Transfer Agent (MTA) infrastructure, scalability, IP management, encryption, and DMARC support, working from conception through production operation. • Contribute to technical design discussions on how the relay integrates with existing inline products (outbound DLP, behavioral outbound, misdirected email), helping define the architecture of the broader Mail Flow platform.
Sr. Lead AI Engineer KlaviyoSr. Lead AI EngineerBoston, MA$216,000–$324,000 / yearYou’ll own architecture and execution for complex, distributed backend systems; guide other engineers through design and implementation; and partner closely with product, machine learning, and data science to turn AI ideas into reliable, scalable production capabilities. You’ve built and shipped generative or agentic AI applications (e.g., LLM‑backed flows, tool‑using agents, retrieval‑augmented systems) and are comfortable with prompt design, few‑shot approaches, fine‑tuning, and evaluation.
Manager, AI Marketing Orchestration, GTM Engineer SarnovaManager, AI Marketing Orchestration, GTM EngineerBoston, MAThis role transforms marketing from a manual, channel-driven function into a scalable, AI-powered growth engine by automating execution, improving speed to market, and increasing efficiency across campaigns. The Manager, AI Marketing Orchestration will design, build, and optimize agentic marketing workflows that drive scalable growth across email, paid media, data and content.
Senior Software Engineer, Agent Platform KlaviyoSenior Software Engineer, Agent PlatformBoston, MA$148,000–$222,000 / yearIn addition to base salary, our total compensation package may include participation in the company’s annual cash bonus plan, variable compensation (OTE) for sales and customer success roles, equity, sign-on payments, and a comprehensive range of health, welfare, and wellbeing benefits based on eligibility. We have a big opportunity to build state-of-the-art AI and machine learning technologies at Klaviyo to power our products and develop AI agents that can automatically create and execute marketing or customer experiences, strategies, and campaigns for any business.
Senior Software Engineer - Growth KlaviyoSenior Software Engineer - GrowthBoston, MA$148,000–$222,000 / yearYou will define the architectural approach and technical strategy for your area of responsibility, anticipating scalability and reliability needs, including leveraging AI agents in our work and delivery, ensuring the solution is robust, scalable, and adheres to best practices for security, performance, and maintainability. In addition to base salary, our total compensation package may include participation in the company’s annual cash bonus plan, variable compensation (OTE) for sales and customer success roles, equity, sign-on payments, and a comprehensive range of health, welfare, and wellbeing benefits based on eligibility.
Senior Software Engineer - Profiles, Lists and Segments KlaviyoSenior Software Engineer - Profiles, Lists and SegmentsBoston, MA$148,000–$222,000 / yearPartnering closely with product managers, data scientists, and other platform teams, you’ll help define scope, translate complex data and UX problems into practical implementations, and build intuitive workflows that give customers confidence in their audiences. In addition to base salary, our total compensation package may include participation in the company’s annual cash bonus plan, variable compensation (OTE) for sales and customer success roles, equity, sign-on payments, and a comprehensive range of health, welfare, and wellbeing benefits based on eligibility.
NewAssociate Distribution Engineer LeidosAssociate Distribution EngineerFramingham, MA$50,700–$91,650Utilities and mobile operators rely on our Power Delivery Services Team for reliable power and telecommunication expertise, as reflected through our work with more than 50 investor-owned utilities, more than 160 municipals/cooperatives, as well as a growing number of mobile operators, local utility providers and private developers. Bachelor's Degree in an Engineering discipline or related field and six plus (6+) months of prior relevant experience working directly with an electric utility or with a consulting/contracting company performing design engineering for electric utilities.
Senior Electrical Engineer - Industrial - Danvers, MA Michael Page USASenior Electrical Engineer - Industrial - Danvers, MADanvers, MA$125,000–$180,000 / yearFull timeMy client is a global technology leader in semiconductor manufacturing equipment, providing innovative solutions that enable the production of advanced chips used in consumer electronics, automotive applications, communications, and industrial technologies. The Senior Electrical Engineer is responsible for the design, development, and support of complex electrical and electromechanical systems used in advanced semiconductor manufacturing equipment.
NewManager, Cloud Engineer - Terraform KPMGManager, Cloud Engineer - TerraformBoston, MAQualifications: Minimum five years of recent experience in IT infrastructure technology management and architecture including IaaS/PaaS/DevOps cloud transformation programs and infrastructure automation, prior system/storage; admin/engineering experience and consulting experience; four years of cloud strategy, migration, and transformation leadership including cloud services (IaaS/PaaS) implementation & migration, including Azure or AWS. Additional desirable experience in infrastructure automation and instrumentation (Unix Admin, Scripting / Programming Capabilities, SDLC Process Knowledge), Unified Communications, Collaboration, Database/application server architecture, network, information security, GenAI, RAG.
Staff Electrical Engineer - Substation Gables Search GroupStaff Electrical Engineer - SubstationNewton, MA$120,000–$150,000Come join a collaborative team shaping the future of energy infrastructure — with real opportunities for career growth, hands-on mentorship, and the chance to work on high-impact projects that strengthen the power grid for the communities that depend on it. We're seeking a Staff Electrical Engineer to support the design and engineering of high-voltage substations (13kV–500kV) for projects across the U.S. and internationally.
Senior Software Engineer II DoubleVerifySenior Software Engineer IIBoston, MA$107,000–$193,000 / yearRockerbox empowers marketing executives to confidently make data-driven decisions, helping brands such as Tula, Figs, and Burton with the strategic decision-making that drives growth. You’ll partner closely with product managers to define requirements, design intuitive data endpoints, and deliver seamless integrations between backend services and user interfaces.