Where to find a freelance web developerKazi

I'm looking to establish a simple, user-friendly, and easy-to-navigate e-commerce website for my candle selling business. The main goal of the website is to sell my products online and create a strong online presence for my brand. Key Features: - Shopping Cart: I want customers to be able to easily select and purchase multiple items. - Customer Reviews: This feature will help build trust with potential buyers and enhance the overall shopping experience. - Product Search and Filtering: As my product range expands, it's essential for customers to be able to easily find what they're looking for. Ideal Skills and Experience: - Prior experience creating e-commerce websites is a must. - Familiarity wi...

I'm looking for a Wix expert to help me build a simple, engaging community website for bridge enthusiasts. Ideally, this person would meet with me via zoom to collaborate on projects. I also would like to learn how Wix works by watching you develop these projects. Ultimately, I want to be able to make simple changes myself. Here are some things I have in mind: (1) I have created a chatbot on that I want to connect to the website (2) I want two levels of membership-paid and free so when a member signs in, they will go to the "free member page or the paid member page" (3) there will be "chat lounges" available for players to connect (4) there will be a book I wrote...

I'm seeking a skilled WordPress Developer to enhance our Funnelkit cart functionality. Currently, the cart has a loading delay when customers adjust item quantities, which hampers user experience. I need this delay completely eliminated. Key Requirements: - Modify the current theme's Funnelkit cart plugin to remove the loading delay when changing item quantities. - Ensure the cart total updates instantly after each quantity change. Ideal Skills: - Extensive experience with WordPress and Funnelkit cart plugin. - Proven track record of modifying core functionalities of WordPress plugins. - Strong coding skills to create custom code snippets as needed. Please provide a quote for this task.

I am seeking a talented HTML developer to convert a single-page Figma design into fully responsive HTML and CSS using Bootstrap 5. Quality and maintainable coding practices are essential. If your work meets expectations, there will be opportunities for additional pages in the future. Requirements: Proficiency in: HTML, CSS, and Bootstrap 5. Bonus: Experience with React.js is a plus. Ability to ensure clean, responsive, and pixel-perfect implementation. Developer must complete this work today and must be able to meet the strict deadline of today by 8:00 PM IST. My budget for this is Rs.1500 - Rs.2000 Max. Please start your proposal with the word "HTML" to confirm you have read the full job description. Proposals wit...

I'm in need of a skilled web designer and developer from Latin America who possesses a strong modern design vision. Your portfolio should reflect a clean, professional, and contemporary aesthetic, aimed at creating impactful, user-friendly, and visually stunning corporate websites. This is a freelance role, and I am looking for a professional who can collaborate on a project-by-project basis. For this particular project, I require the creation of a 5-page corporate website. While the exact layout and content will be discussed, expect to include standard pages like Home, About Us, and Contact. Ideal candidates should: - Have a strong portfolio of modern, minimalistic web design - Possess excel...

I am Jeremiah from Eternity Ready. We are a Faith and Family Media Streaming company, We offer TV, Radio, Podcasts and On-demand content. This project is related to data entry for schedules from radio stations. Please read below to learn more. Only bid in our budget to get hired. Project Requirements / Scope: Manually enter or copy & paste schedules for up to 8 Radio stations into my web site. You will also find images to upload for each radio show you enter in the schedule. This should be a very easy job. I will train you. You visit each radio station web site to get the schedules. The images must be high quality. If you can not find a good one on the radio station schedules. I will be prov...

I need someone who can emulate or develop a similar piece of software that has already been made. This software is out dated and was made circa 2002-2004. What you need to know : This game is old (it was released in 2001) and the infrastructure is not as complex as newer mmorpg titles. This might be good and it might be bad but it helps to know. Some radars were released/developed for the original game but they no longer work. Here's an example of one: DAoC Skilla was made for the original game but it is no longer working because the version was built back in the early 2000s and support was not kept. There are source files on that website that you might find useful to copy as well as UI elements that might make this project make more sense. An...

A social media app designed for sports professionals would focus on networking, career development, training, and fan engagement within the sports industry. Below are the key features such an app might include: 1. Professional Profiles Athlete Profiles: Showcase stats, achievements, highlights, and career history. Coach Profiles: Detail coaching experience, certifications, and specialties. Team Profiles: Represent sports teams, rosters, schedules, and achievements. Highlight Reels: Space to upload video clips of key performances, practices, or training sessions. 2. Networking & Community Building Peer Connections: Connect with other athletes, coaches, and sports professionals. Mentorship Programs: Facilitate mentor-mentee relationships for career guidance. Community Gr...

I require a seasoned React.js developer to enhance the user interface of my existing application, focusing specifically on improving its responsive design. You're welcome to join as a developer, and you can work part-time or full time, all remotely. MVP v1 project on here: Once you've had a chance to check the project out, please apply with the letter of "Connect Wallet" button's color at the project. Thank you.

I am looking for a cross-platform (iOS and Android) white label app that delves into the anatomy of the human eye. This app should be rich in content, incorporating text descriptions, 3D models, and videos. Key Features: - Interactive Quizzes: To engage users and test their knowledge. - Search Functionality: Allowing users to easily find specific information. - Bookmarking Sections: Enabling users to save their progress or interesting sections for later. Ideal Skills: - Proficient in cross-platform app development. - Experienced in creating educational apps. - Knowledgeable in 3D modelling and video integration. The aim of this project is to create a comprehensive, interactive, and user-friendly app about the human eye, suitable for both...

I'm in need of an experienced application developer to create an Android-based e-commerce application for my business. The primary focus of this app is to improve customer engagement and drive sales. Key Requirements: - Expert knowledge in Android app development. - Previous experience in creating e-commerce applications is highly desirable. - Skills in UI/UX design to ensure a user-friendly interface. The ideal freelancer for this project would be someone who can create a robust, engaging, and easy-to-navigate e-commerce application that can help propel my business to new heights. Please include examples of your previous work in your proposal.

Android Developer for AI Girlfriend App - Local LLM Integration (Uncensored, Lightweight) Description: I am seeking an experienced Android developer to help improve my AI Girlfriend app. The app currently uses a custom API and a backend that integrates with ChatGPT for conversations. However, I want to enhance the app by allowing it to run a local large language model (LLM) on the user's device, removing any external dependencies for a more seamless and uncensored experience. Objectives: Local LLM Integration: Replace the current ChatGPT integration with a local LLM that can run directly on the user's device. The goal is to make conversations more interesting, personalized, and uncensored, without an...

...LAC PA) Job Summary We are seeking a highly motivated and detail-oriented individual for the role of Internet Link Poster. The primary responsibility is to post specific links all across the internet on a variety of websites, forums, platforms, and communities. You must find suitable locations to post these links and ensure they are relevant, well-placed, and stay permanently online. Only links that remain live will count toward your daily target of 160 links. This full-time position will become easier with practice as you learn to identify the best posting opportunities efficiently. Key Responsibilities 1. Posting Links Across the Internet: You are responsible for posting links on different websites and platforms every day, including but not ...

We are looking for an experienced developer to build a WhatsApp bot that automates the donation process for our platform. The bot will guide users through donation setup, calculate breakdowns, generate Stripe payment links, and schedule payments using our existing AWS database and payment intent scheduler. Responsibilities: 1. WhatsApp Bot: • Develop a conversational WhatsApp bot using WhatsApp Business API or Twilio. • Implement flows for donation setup, cause selection, and confirmations. 2. AWS Integration: • Save user data (donation preferences, breakdowns, schedules) to our existing AWS database securely. 3. Stripe Integration: • Dynamically generate Stripe payment links and process confirmations. • Integrate with our paymen...

I'm in need of a full-stack web developer to create a website using , React and Tailwind. As well as a backend api to inform the websites functionality. The full breakdown of the website is below: DO NOT contact me or give an offer until after reading the entire document.

I have an existing project and looking for an additional developer. I provide pdf's like the ones attached and you use FlutterFlow and custom Flutter/Dart where needed. 1) We use Github for the project. 2) Must have experience deploying FlutterFlow apps to App and Play stores 3) Must overlap at least 3 hours/day with Eastern Standard Time zone between 8am to 6pm 4) bid your hourly rate - if you tell me your hourly rate is different than what you bid i will not hire you

I'm a marketing agency owner focusing on promoting event venues and related services. I'm seeking a talented freelance SEO expert, primarily skilled in Technical SEO, to join my team. Key Responsibilities: - Enhance the online visibility of our venues through effective SEO strategies. - Prioritize and execute technical SEO tasks, specifically: - Site speed optimization to improve user experience and search engine rankings. - Ensuring mobile responsiveness of our sites to cater to the increasing number of mobile users. - Fixing crawl errors to ensure all parts of our website are accessible to search engines. Ideal Skills and Experience: - Proven expertise in Technical SEO, with a strong emphasis on si...

We are seeking an experienced Fullstack/Frontend Developer who is skilled in both development and communication. The ideal candidate will have a strong command of modern web technologies and frameworks, as well as the ability to clearly articulate ideas, collaborate with teams, and deliver high-quality solutions. Key Requirements: - Proficiency in JavaScript and TypeScript - Proficient in both frontend and backend development - Expertise in React and/or Angular - Backend development experience with Node.js - Testing frameworks such as Jest and Cypress - Strong debugging and problem-solving skills - Prior experience in building web applications - Excellent communication skills for seamless collaboration - Familiarity with implementing real-time chat featu...

I'm seeking a Python developer with experience in trading tools. I need a program that scans stock market data from the NSE FNO. The scanner should filter stocks based on price movements and technical indicators. Key Requirements: - Proficiency in Python - Experience with trading software development - Ability to create a scanner that exports results in .csv format Ideally, the freelancer will have a good understanding of stock trading and technical indicators. Please include examples of relevant projects in your bid.

...looking for a skilled Flutter developer to resolve an issue with the payment functionality in my app. The app uses the in_app_purchase package, and the problem occurs when testing on TestFlight on an iPhone. Issue: When a user clicks the subscription button on the Subscription Page (), the Apple In-App Purchase payment window does not open as expected. Requirements: Identify the Problem: Review the code in and the implementation of the in_app_purchase package. Check if the issue is caused by the Flutter code or by incorrect Apple Developer Console settings. Fix the Issue: Ensure that clicking the subscription button triggers the Apple In-App Purchase payment window correctly. Verify the Solution: Provide me with a version of the app to...

We are seeking a talented and experienced freelance UI/UX designer to revamp the website for Vibranium, a leading company specializing in website UI/UX design. The ideal candidate will be responsible for enhancing the user experience, creating visually engaging layouts, and improving the overall interface design. The project will focus on delivering a sleek, modern, and intuitive design for our business portfolio website, ensuring it is responsive and optimized for both desktop and mobile users. Key Requirements: -Proven experience in UI/UX design, with a strong portfolio -Proficiency in design tools (Figma, Adobe XD, Sketch, etc.) -Knowledge of web development technologies (HTML, CSS) -Understanding of SEO-friendly design practices -Abili...

Chemical Engineer Needed for Creating Industrial Chemical Datasheets and Catalogs **Description:** We are looking for a freelance Chemical Engineer with expertise in industrial chemicals to create professional datasheets and catalogs for our products. **Requirements:** - Research and compile technical specifications and industry applications. - Prepare datasheets and catalogs in editable formats (Word, Excel, and PDF). - Ensure the output is professional, accurate, and visually appealing. **Skills Required:** - Strong knowledge of industrial chemicals. - Proficiency in Microsoft Word, Excel, and PDF tools. - Excellent research and writing skills.

I'm looking for an experienced full-stack developer to help me design a website from React and Flutter templates/boilerplate. The project requires integrating a RESTful API, implementing various design and functionality changes, and finally hosting the site with robust security measures. Key Responsibilities: - Modify and enhance a website based on React and Flutter templates - Integrate a RESTful API into the site - Implement design changes and functionality enhancements - Handle web hosting and deployment with a focus on security Ideal Skills and Experience: - Proficient in React / Flutter - Extensive experience with designing and modifying templates - Expertise in RESTful API integrations - Proven track record in secure w...

I'm looking for a Python developer. Key Responsibilities: - Develop Python scripts for various tasks Ideal Skills: - Strong knowledge and experience in Python See attached text file for details and say "Halo" so i know you have read the file otherwise i will ignore your bid Needed to complete wikipedia script quickly within hours if you can budget is 12 usd per site i only need scripts

I have a pythi=on website I would like to add features and upgrades to in order to function better. Furthermore I am looking for an experienced coder and software developer as we have many projects that need to be worked on.

I'm seeking a skilled web developer who can assist in creating an Android app. This app will include in-app purchases as a key feature. Ideal Skills: - Extensive experience in web development - Proficient in Android app development - Knowledgeable in implementing in-app purchase systems - Previous experience with developing similar projects - Fluent in 150+ languages (a plus) Please, only apply if you're capable of delivering a high-quality product.

We are seeking a skilled Meta Ads Expert to run a B2C lead generation campaign focusing on the loan/debt settlement industry. The ideal candidate will have hands-on experience with creating, optimizing, and managing Meta (Facebook & Instagram) ad campaigns that generate high-quality leads. This is a freelance position with an immediate start. Key Responsibilities: Campaign Planning & Strategy: Develop a comprehensive B2C lead generation strategy tailored to the loan/debt settlement niche. Identify the target audience and create a buyer persona for precise ad targeting. Ad Creation & Management: Design engaging ad creatives (image, video, and copy) that comply with Meta advertising policies, especially for sensitive indust...

I'm seeking a Ruby on Rails expert to develop a custom web application, specifically a user management system. Key Features: - User Authentication & Authorization: Implement secure and efficient user login, registration, and permission systems. - User Profile Management: Create a system for users to manage their personal information and settings. - Role-Based Access Control: Develop a system that assigns different access levels to users based on their roles. Ideal Skills: - Proficient in Ruby on Rails with a strong portfolio of custom web applications. - Experience in developing user management systems. - Strong understanding of implementing security measures in web applications. - Excellent pro...

I'm in need of a skilled web developer to create a comprehensive educational website. Key features of the site will include: - Online Courses: The website should have a robust system to host and manage online courses. - User Registration and Profiles: A user-friendly registration process is essential, along with personalized profiles for each user. - Blog and Articles Section: The site needs an integrated blog to share articles and updates. - Freelance Section: A dedicated space for freelancers is required, allowing for interaction and collaboration. The ideal candidate for this project should have a strong background in web development, with specific experience in creating educational platfor...

I have an existing project and looking for an additional developer. I provide pdf's like the ones attached and you use FlutterFlow and custom Flutter/Dart where needed. 1) We use Github for the project. 2) Must have experience deploying FlutterFlow apps to App and Play stores 3) Must overlap at least 3 hours/day with Eastern Standard Time zone between 8am to 6pm 4) bid your hourly rate - if you tell me your hourly rate is different than what you bid i will not hire you

I am looking for an experienced web developer to build an E-commerce site for my service-oriented business. The site should be user-friendly, professionally designed, and capable of handling customer transactions smoothly. Key Requirements: - Design and develop an E-commerce site focused on selling services - Integrate a reliable and secure payment gateway - Implement a customer review system to enhance credibility and user interaction Ideal Skills: - Proficiency in web development, particularly E-commerce platforms - Experience with integrating secure payment gateways - Ability to create an interactive and user-friendly interface - Knowledge of implementing customer review systems on websites I am looking for a professional...

I'm looking for an Excel expert to create a macro that will help in task automation. The specific tasks to be automated will be discussed later. Ideal Skills: - Proficiency in Microsoft Excel - Experience in developing macros for task automation - Excellent problem-solving skills - Ability to understand and analyze tasks for automation Please provide examples of similar projects you've completed in your proposal.

I'm seeking a skilled React Developer to spearhead our Front End development efforts. You will be responsible for creating and enhancing application functionality, all while ensuring the user experience remains top-notch. Your expertise in optimizing RESTful APIs and your ability to collaborate with cross-functional teams in an Agile environment will be key to our success. Key Responsibilities: - Lead the development of user-friendly web applications using React within the Microsoft stack - Optimize RESTful APIs for our data-driven applications - Ensure high code quality through regular governance and reviews - Collaborate with various teams and customers in an Agile setting Requirements: - Over 4 years of hands-on experience with React, Jav...

I'm seeking a seasoned React Native developer experienced with the Skia library for both iOS and Android platforms. The primary goal of this project is to implement advanced graphics rendering capabilities. Key Requirements: - Proficient in React Native with a proven track record - Extensive experience with Skia library - Solid understanding of both 2D and 3D graphics rendering - Ability to create engaging and visually appealing applications The ideal candidate will have a strong portfolio demonstrating their skills in enhanced graphics rendering, custom animations, and UI/UX components using the Skia library.

I'm seeking a seasoned Ruby on Rails developer for the maintenance and updates of an existing Business Services web application. The system is designed to manage client details, documents, and operations. Key Responsibilities: - Regular maintenance and updates of the web application - Ensuring system efficiency and functionality Ideal Skills: - Proficiency in Ruby On Rails - Experience with Docker and SQL - Previous work on Business Services systems Please note, the selected developer must be contactable and able to work during UK standard office hours.

I'm loo...looking for a seasoned web developer who is well-versed with the Framer platform. The main purpose of this website is to showcase my portfolio, so it needs to be visually appealing and user-friendly. Key Features: - A Contact Form: This is essential for potential clients or collaborators to reach out to me easily. - Client Testimonials: I want to incorporate some positive feedback from my past clients, so a section dedicated to testimonials is necessary. Design: I already have a complete design for the website, so your job will primarily be to bring this design to life on the Framer platform. Ideal Skills: - Proficiency in Framer platform - Web development - Implement...

I'm seeking a seasoned Android(Kotlin) & iOS(Swift) Developer, boasting a minimum of 6 years experience, to build a dynamic Android application. Key Requirements: - Extensive experience in Android(Kotlin) & iOS(Swift) app development. - Deep understanding and expertise in integrating social media platforms, search functionalities - Mastery of implementing OAuth for user authentication, primarily through Google and Facebook. The primary feature of this application will be its social media integration. It should allow seamless sharing and connectivity with the aforementioned platforms. The ideal candidate will have a proven track record in developing engaging, user-friendly Android applications with robust social media capabilities. E...

...hiring to build a chess training app, and planning to build it over a few stages. There will be a small initial period to build the app and test viability, which should be fairly quick since almost all of the features are based on a creative use of open source code. I'm going to be a bit cagey in this post, because I do have a plan for these features but I don't want to give too much away for how I'll be doing it. If the initial build goes well, then I will move on to a secondary stage to build out the initial version of the app. After this stage I will engage in user testing and feedback. The final stage will involve features that are a bit more complex, and "...

Job Title: AI Assistant Developer – Lead Response Integration () Location: Remote Contract Type: Freelance/Contract Overview: is seeking a skilled AI developer to set up and integrate key features into our AI assistant. The goal is to enable the assistant to efficiently process incoming leads, initiate calls within 5 minutes, and engage with the lead in a personalized manner—calling them by name and collecting relevant information for follow-up. The successful candidate will work closely with our team to refine this process and ensure a seamless, high-quality user experience. Responsibilities: Lead Detection and Processing: Configure the AI assistant to detect incoming leads in real time and trig...

EUWEB 250110 - E-commerce WordPress Developer/Admin I'm looking for a seasoned WordPress Developer/Admin to assist in enhancing my E-commerce site. This project will consist of 10 Units of Work (UoW), each lasting 4 hours, based on my needs. Need: Expertise in WordPress/ADMIN development specifically for E-commerce; Ability to implement customer review functionalities; Skills in creating a personal blog on WordPress; ...plz, like to work with us (as WordPress Developer/Admin, which we need) ? ...fullset 10 UoW (10 half/day, a week for month, ...or 2 hours each not holidlays), when/where like; UoW - Unit of Work, 4 hours/each, on our need; ...choice when work or useful for the work goal; ...at your home, in slippe...

...Proficient in customizing Zoho CRM modules, fields, and workflows - Ability to create and customize reports and dashboards in Zoho CRM - Familiarity with Zoho CRM APIs and integration with other systems - Excellent problem-solving and troubleshooting skills for ongoing support - Proven track record of providing ongoing support for Zoho CRM projects Key Responsibilities: - Customize Zoho CRM to meet specific business requirements - Develop and implement custom modules, fields, and workflows - Create and customize reports and dashboards for data analysis - Troubleshoot and resolve any issues or errors in the Zoho CRM system - Provide ongoing support and maintenance for Zoho CRM We are seeking an experienced Zoho Developer who specializes in CRM customization and can...

We are looking for a talented freelance video editor to create a short, impressive, and dynamic Instagram Reel. The Reel should capture attention within the first few seconds, follow current Instagram trends, and convey a powerful message in 15 seconds or less.

I am looking for a skilled Python or JS developer with expertise in web scraping, Selenium, and HTML parsing to enhance and complete a job scraping tool for the Adzuna job portal. Project Goals: code must fetch all job listings from Adzuna for a given search query URL (e.g., ). Handle cases where JSON-LD data is missing by falling back to HTML parsing to extract all relevant details. Current Issues: my code scrapes some job data (titles, descriptions, company names, etc.), but many fields remain blank. Not all job listings are fetched; the script currently stops at ~157 jobs out of ~410 listed. Fallback HTML parsing is insufficient, leaving many fields incomplete. Requirements: Comprehensive Data Extraction: Fetch all job ...

Project Overview: We are looking for a skilled web developer to help build a rosary reading web that simplifies the experience of reading and praying the rosary. The first version of the web will focus on providing an easy-to-use interface for reading rosary scripts and counting the recitations of "Hail Mary". The web will be designed for both beginners and advanced users, with a clean, user-friendly interface and the ability to switch between modes. Key Features for First Version: Rosary Scripts: Display full scripts of the rosary prayers (Joyful, Sorrowful, Glorious, etc.) Count the number of recitations of "Hail Mary" and other key prayers. The ability to track progress during pray...

I need a fullstack developer skilled in PHP and React Native to work on my application. The specifics of the project will be discussed, but I expect you to have the capability to handle the full stack of the application. I have my own doctor app, i need developer who can work on agora api which i used for video calling. So am not able to connect my call, when am trying to join call am getting back screen. Am not sure where is issue backend or frontend, but i need a developer who can handle both side work this will be long term relationship job. When this task is done i will add more 3 modules one by one, but first i wanna fix this issue urgent basis, Key Requirements: - Extensive experience with PHP for the back...

I'm seeking a talented game developer to create a vibrant, physics-based 2D side-scrolling mobile game. In this game, players control a quirky, cartoonish animal that has escaped its owner. The objective is to race through rolling hills, leaping over obstacles, and dodging hazards to escape a looming rainstorm and find its way back home. Key Features: - Gameplay: Players must travel back home while collecting rewards, performing stunts, and mastering timing-based gameplay. - Art Style: The game should adopt a vibrant, cartoonish art style. - Rewards: Players will be collecting coins and power-ups throughout their journey. - Obstacles: The game should incorporate a variety of challenges, including static b...

Job Ad: Professional Web Developer Needed for Hotel Advertisement Platform We are looking for an experienced and professional web developer who can complete the project by strictly deadline end of January [3 weeks] Can code in React (Frontend) frpm scratch as on but with some modern technologies which elements you can see in attach scope of work and Node.js (Backend) which we already have. Developer must have previous experience with hotel-related platforms and can provide proof of previous work. Understands the intricacies of developing large-scale platforms similar to Booking.com. Project Overview: We are developing an advertisement platform for hotels, not a booking platform. This platform will: 1. Allow hotels to list th...

I am in need of a seasoned WordPress developer for a full-time, one-week project. The developer will work on an hourly basis, performing tasks as an integrated, internal employee. The primary focus will be building new corporate or portfolio sites. Key Requirements: - Extensive WordPress experience, particularly in building new sites - Proven track record of creating mobile-compatible websites - UI/UX design experience is preferred - Ability to adhere to detailed design and branding guidelines This project is perfect for a developer who can work efficiently and collaboratively, with a strong focus on quality and attention to detail. Successful completion of this project may lead to further opportunities.

Descripción del Proyecto: Actualización y Optimización de Website Estamos buscando un profesional freelance para realizar una actualización integral de nuestro sitio web. Los principales objetivos y requerimientos del proyecto son los siguientes: Tareas a Realizar: Optimización General del Sitio Web: Mejorar la velocidad de carga y el rendimiento del sitio. Corregir posibles errores de diseño responsivo y asegurar una correcta visualización en dispositivos móviles, tablets y desktop. Revisar y optimizar la arquitectura del sitio para una mejor experiencia de usuario (UX). Integración de Métodos de Pago: Binance Pay: Implementación de un sistema que permita aceptar pagos mediante Bin...

years of experience 8 years . Proven experience in Amazon Alexa . Hands-on experience in OpenSearch, Kefka, Splunk, Glue,pyspark,EMR, Lambda,dynamo DB . Coding: python,c++, Java, object-oriented language, or other modern programming language . Integrate Alexa skills with third-party APIs, databases, and other systems