Hire the Best Functional Programmers in California

More than 3,000 reviews on G2
Rating is 4.5 out of 5.
4.5/5
of Upwork by G2 peer reviewers
Bill A.

Los Angeles, California

$70/hr
5.0
5 jobs

Senior Business Analyst, Developer, Database Designer, and Software Architect with a proven record of delivering effective results for complex business problems. Master of business/IT collaboration, object-oriented software development, and problem solving. Conference speaker, author and data dog.

  • Microsoft SQL Server
  • Database Design
  • Visual FoxPro
  • FoxPro Programming
  • Software Architecture
  • Data Modeling
  • Business Analysis
  • Object-Oriented Design
Kevin Leroi C.

Covina, California

$90/hr
4.8
394 jobs

Over the last 20 years I have developed a wide range of websites from simple HTML websites to Full dynamic websites that use PHP, AJAX and MYSQL. I have a passion for helping small businesses get off the ground and running. My strength lies in the fact that I not only build sites to make money online but I own sites that make money online. So I have the insight to provide consulting on what internet based technology tools to use as well as helping them put those tools to use. I love doing all aspects of building websites from front-end to backend. As most web designers that have been in the business for many years I have lots of other skills that help me to create beautiful and functional websites.

  • PHP
  • API Integration
  • Git
  • CSS
  • JavaScript
  • MySQL
  • Angular
  • HTML
  • Joomla
  • NativeScript
Igor K.

San Diego, California

$90/hr
4.9
542 jobs

Senior WordPress Developer. Reliable and responsive. Result-oriented work. On time. "Top Rated Plus" Upwork premium freelancer, member of an Upwork PRO group. 14+ years skill in full-stack web site development (prototype, graphic design, front-end, back-end, SEO). Back end experience: PHP (WordPress, Laravel), C# (ASP .NET MVC, Web API, Entity Framework, Orchard, Kooboo, Umbraco). Front end experience: HTML5 / CSS3, SASS, LESS, Bootstrap 5, Html5 animation, JS, jQuery, AJAX, Json, Rest API, Angular 1-2-4, React.js, Vue.js, Node.js, Three.js. Other experience: Windows/Unix Server administration, Git, Azure, AWS and cloud solutions. In terms of WordPress can provide: ✔️ custom theme design or theme/template modification; ✔️ responsive HTML (will pass Google mobile-friendly test, work on any device and OS); ✔️ retina display support; ✔️ HTML5 animation if needed; ✔️ WordPress/Woo back end; ✔️ WordPress multisite and membership, BuddyPress, bbPress; ✔️ custom plugin development; ✔️ 3rd-party services and payment systems API integration; ✔️ SEO, make AMP compliant, setup CDN (Cloudflare); ✔️ support; ✔️ warranty. Great experience with: ✔️ e-commerce; ✔️ payment systems integration (PP, Stripe, Authorize.net and similar); ✔️ Google Maps API (custom design, clusters, routing, radius, speed/time/distances calculation, etc.); ✔️ responsive CRM and dashboards, high-traffic web-projects; ✔️ experience with Microsoft Power BI. Keep the warranty, always available, fast response and turnaround. === TAGS === WordPress Developer ; WordPress expert ; Fullstack developer.

  • WordPress
  • WooCommerce
  • PHP
  • WordPress Plugin
  • WordPress Development
  • Elementor
  • WordPress Theme
  • WordPress Security
  • WordPress Multisite
  • WordPress Customization
  • Web Design
  • CSS
  • JavaScript
  • HTML
  • Vue.js
Michael C.

Playa Vista, California

$65/hr
4.9
145 jobs

I help businesses build high-quality WordPress websites that look premium, load fast, and convert visitors into customers. I’m a senior WordPress developer and UI/UX specialist with over 15 years of experience designing and building high-quality, conversion-focused websites from the ground up. I specialize in creating clean, modern, and highly functional WordPress sites that position businesses as premium, credible, and trustworthy. Whether you need a full redesign, a custom build, or ongoing improvements, I deliver solutions that are both visually refined and technically sound. My work is focused on three core principles: • Clear, professional design that elevates your brand • Fast, reliable performance across all devices • Conversion-focused structure that drives inquiries and results I’ve worked with service-based businesses, consultants, construction companies, education providers, and professional firms to improve their online presence and generate better leads. ⸻ What I Can Help You With Custom WordPress Development • Full website design and development • Custom themes and Elementor builds • PSD / Figma to WordPress • Landing pages optimized for conversion WordPress Optimization & Improvement • Speed optimization and performance tuning • Website redesigns and modernization • Mobile optimization • UX improvements and structural cleanup Advanced WordPress Functionality • ACF Pro and Custom Post Types • WooCommerce development and customization • API integrations • Custom functionality and troubleshooting Maintenance & Support • Bug fixes and issue resolution • Ongoing updates and improvements • Site cleanup and stabilization • Long-term technical support ⸻ Technical Skills WordPress, Elementor, WooCommerce PHP, JavaScript, HTML5, CSS3, AJAX, SQL ACF Pro, Custom Post Types Speed optimization and performance tuning Responsive and mobile-first development API integration Design tools: Adobe Photoshop and Illustrator ⸻ What You Can Expect Working With Me • Clear communication • Professional, detail-oriented execution • Reliable turnaround times • Clean, maintainable code • Long-term support when needed My goal is not just to build a website, but to create a strong, professional online presence that supports your business growth. If you’re looking for a dependable developer who understands both design and functionality, I’d be happy to discuss your project.

  • WordPress Development
  • Web Development
  • WordPress
  • CSS 3
  • Yoast SEO
  • PHP
  • JavaScript
  • Elementor
  • WordPress Plugin
  • WordPress e-Commerce
  • PSD to WordPress
  • Website Redesign
  • Website
  • Landing Page
  • WordPress Theme
Sohail M.

Lake Forest, California

$30/hr
5.0
11 jobs

AI Agent Developer building Voice AI agents, AI chatbots, RAG pipelines, and AI automation using OpenAI API, Python, FastAPI, and n8n. I connect AI systems to CRMs, calling platforms, and knowledge bases to solve real business problems, not demos. Every project I've delivered carries a 5-star rating and a client endorsement. 📈 Selected projects ✅ AI fraud detection platform (Next.js, Stripe) cutting chargebacks by up to 98% using behavioral pattern recognition and machine learning instead of static rule engines, PCI DSS compliant ✅ Inbound and outbound Voice AI platform on Twilio, Retell AI, and ElevenLabs, cutting call handling time by 35% and improving customer satisfaction by 18% through live transcription and intelligent routing ✅ Multi-channel AI chatbot using OpenAI API, LangChain, and Pinecone, integrated with Bitrix24, Zoho, and Salesforce, lifting outreach efficiency by 60% through automated lead qualification and human handoff ✅ RAG-powered multilingual knowledge platform with vector database retrieval, cutting manual document search time and delivering low-hallucination answers across business knowledge bases ✅ n8n automation workflows connecting LLMs with CRMs, Zendesk, HubSpot, and internal systems, removing repetitive manual work from daily operations 🛠️ Built with: OpenAI API, RAG, Pinecone, n8n, Twilio, Retell AI, ElevenLabs, LangChain, FastAPI, Python, MongoDB, Next.js, React 💬 Tell me what you're building. I'll tell you honestly whether it needs a voice agent, a chat agent, or both.

  • AI Agent Development
  • Retrieval Augmented Generation
  • n8n
  • Twilio API
  • Zapier
  • AI Chatbot
  • Chatbot Development
  • Large Language Model
  • Conversational AI
  • AI Speech-to-Text
  • Automatic Speech Recognition
  • LangChain
  • ElevenLabs
  • Python
  • FastAPI
  • Next.js
  • Vector Database
  • Natural Language Processing
  • AI App Development
  • PostgreSQL
Corey R.

Temecula, California

$85/hr
5.0
53 jobs

Leading the web development and providing insights/ideas to drive software design success is the hallmark of my 15- year career. SKILLS • Modern JS Front-end Frameworks (React/Angular/Vue) + Typescript • Single-page-applications (SPAs) development using React, Redux, Context, React Hooks, and Typescript • Next.js proficient experience (SSR/SSG/Data fetching/API design/Routing architecture) • Integration of UI frameworks(Tailwind CSS/Chakra UI/Ant Design/Bootstrap/Material UI) + styled-components • RESTful API design, GraphQL/Apollo, and Node.js/Express/NestJs • AWS serverless structure with Lambdas, API Gateway, SNS/SQS, EC2/S3, Secret Manager, RDS/DynamoDB, Amplify, Cognito, ... • App hosting, CI/CD experience, and TDD(Unit testing/e2e testing) • Application development methods (Agile, Kanban, Waterfall), Project management tools (Jira, Atlassian, Asana, Notion), and Version control management (Git, Bitbucket, SVN) I am passionate about fostering cross-collaboration to support process improvement initiatives and best practices. I am excited to work with teams committed to challenging the status quo by identifying and evangelizing opportunities to improve engineering productivity and outcomes. In addition to my professional achievements, I possess a Bachelor of Science in Computer Programming from Northern Illinois University.

  • PHP
  • JavaScript
  • CSS
  • TypeScript
  • SCSS
  • MySQL
  • Node.js
  • React
  • HTML5
  • jQuery
  • ExpressJS
  • Git
  • Vue.js
  • Angular
  • Next.js

How it works

Post a job for freePost a job

Tell us what you need. Create your own job post or generate one with AI then filter talent matches.

Hire top talent fast

Consult, interview, and hire quickly, so you can meet the freelancers you're excited about.

Collaborate easily

Use Upwork to chat or video call, share files, and track project progress right from the app.

Payment simplified

Manage payments in one place with flexible billing options. Only pay for approved work, hourly or by milestone.

Don't just take our word for it

How do I hire a Functional Programmer in California on Upwork?

You can hire a Functional Programmer in California on Upwork in four simple steps:

  • Create a job post tailored to your Functional Programmer project scope. We'll walk you through the process step by step.
  • Browse top Functional Programmer talent on Upwork and invite them to your project.
  • Once the proposals start flowing in, create a shortlist of top Functional Programmer profiles and interview.
  • Hire the right Functional Programmer for your project from Upwork, the world's largest work marketplace.

At Upwork, we believe talent staffing should be easy.

How much does it cost to hire a Functional Programmer?

Rates charged by Functional Programmers on Upwork can vary with a number of factors including experience, location, and market conditions. See hourly rates for in-demand skills on Upwork.

Why hire a Functional Programmer in California on Upwork?

As the world's work marketplace, we connect highly-skilled freelance Functional Programmers and businesses and help them build trusted, long-term relationships so they can achieve more together. Let us help you build the dream Functional Programmer team you need to succeed.

Can I hire a Functional Programmer in California within 24 hours on Upwork?

Depending on availability and the quality of your job post, it's entirely possible to sign up for Upwork and receive Functional Programmer proposals within 24 hours of posting a job description.