Jonah is available for hire
Hire JonahJonah Elbaz
Verified Expert in Engineering
Full-Stack Developer
Montreal, QC, Canada
Toptal member since February 25, 2019
Bio
For Jonah, delivering a project's requirements is non-negotiable. Fortified by his time as a full-stack developer, product lead, and engineering lead, tethering to the users' needs and psyche is his most powerful tool and the driving force of his delivery guarantee. Jonah believes that for a project to be successful, the objective must drive the development rather than having development limitations on the requirements.
Portfolio
Xborg
React, NestJS, RAG Systems, Large Language Models (LLMs), OpenAI, Claude Code...
HOOT APP INC.
iOS, Android, Blockchain, Database Architecture, Mobile App Development...
Chromie Health, Inc
Architecture, NestJS, React, Large Language Models (LLMs), RAG Systems, Twilio...
Experience
- Full-stack Development - 9 years
- TypeScript - 8 years
- Node.js - 8 years
- React - 7 years
- React Native - 6 years
- PostgreSQL - 5 years
- Google Cloud Platform (GCP) - 5 years
- Artificial Intelligence (AI) - 5 years
Preferred Environment
MacOS
The most amazing...
...concept I've followed is that the more of the picture you see, the more powerful you become.
Work Experience
CTO for AI Fan Enagement Company
2023 - PRESENT
Xborg
- Managed large team of engineers delivering the leading Fan Technology in eSports, providing support for the biggest Teams in the scene (https://fanbase.gg/).
- Led the AI initiative for the company, bringing the latest product to life (https://copilot.fanbase.gg/).
- Built complex AI systems, serving thousands with bespoke LLM technologies.
Technologies: React, NestJS, RAG Systems, Large Language Models (LLMs), OpenAI, Claude Code, Embeddings from Language Models (ELMo), Fractional CTO, Artificial Intelligence (AI), Agentic AI, API Integration, Architecture
[Toptal Managed Delivery] Freelance Technical Lead for AI driven Social Media App
2025 - 2026
HOOT APP INC.
- Managed a team of engineers delivering an AI and geolocation-driven social media app.
- Worked closely with all members of all teams to yield the delivery.
- Oversaw initial release to several thousand users.
Technologies: iOS, Android, Blockchain, Database Architecture, Mobile App Development, Technical Leadership, Amazon Web Services (AWS), Large Language Models (LLMs), RAG Systems, OpenAI, Fractional CTO, Artificial Intelligence (AI), Agentic AI, API Integration, Architecture
[Toptal Managed Delivery] Freelance Tech Lead for Healthcare AI Platform
2025 - 2025
Chromie Health, Inc
- Developed a Nurse Management and Dispatch system, conducting a team of developers towards a successful, on time, delivery.
- Prioritized HIPAA compliance while still managing to leverage modern LLM/AI as a core pillar of the product.
- Handled PII management and stripping, with enhanced LLM security protocols.
Technologies: Architecture, NestJS, React, Large Language Models (LLMs), RAG Systems, Twilio, SMS, OpenAI, Fractional CTO, Artificial Intelligence (AI), Agentic AI, Regulated Industries, API Integration, Compliance
[Toptal Managed Delivery] Freelance Tech Lead for Government AI Platform
2024 - 2024
CGCN Group LLC
- Developed a proof of concept of synthetic government polling software for the US.
- Developed proprietary LLM trained on mass poll data.
- Completed a full, multistage discovery across different sections of government tooling backed by AI.
Technologies: Technical Leadership, Database Architecture, React, CI/CD Pipelines, APIs, Node.js, Amazon Web Services (AWS), PostgreSQL, Google Cloud Platform (GCP), Artificial Intelligence (AI), Fractional CTO, Agentic AI, API Integration, Architecture
Freelance Full-stack Developer (via Toptal)
2023 - 2024
Freede Solutions Inc.
- Created the front end and gateway for the LLM debt collection chat. By better understanding your position, a collector can guide you to pay your debt at the most suitable time.
- Collaborated on self-hosted LLM requirements to recreate a seamless user experience.
- Created a customer dashboard to configure and prepare their assistant to meet industry compliance.
Technologies: Node.js, React, JavaScript, OpenAI, MongoDB, Artificial Intelligence (AI), Agentic AI, Regulated Industries, API Integration, Compliance, Architecture
[Toptal Managed Delivery] Fractional CTO
2022 - 2024
Block Born
- Evolved a business model and developed cutting-edge technology to fuel game development in the gaming industry.
- Deployed custom tokens, contracts, and payout user rewards at scale with game-level frequency.
- Managed a team of engineers and designers to execute the development of top gaming tools for an entire ecosystem. Enforced code, design, and product quality company-wide.
- Led both Block Born and Block Born Studios, producing gaming tools and games. Leveraged tools like Unity, Photon, and PlayFab.
- Integrated a custom AI solution using OpenAI to enhance gamers' question experience.
Technologies: Node.js, Next.js, PostgreSQL, Tezos, Blockchain, Artificial Intelligence (AI), Photon, Full-stack Development, Fractional CTO, Agentic AI, API Integration, Compliance, Architecture
Full-stack Developer
2023 - 2023
Decision Point Weather Corp
- Leveraged complex proprietary meteorological formulas to build a new cutting edge weather delivery site.
- Built both mobile and web applications functioning through the same codebase to minimize development time, resulting in on-time delivery.
- Integrate AdSense and optimize SEO for a thriving live presence.
Technologies: JavaScript, Full-stack, React, Web Development, Mobile Development, React Native, Artificial Intelligence (AI), API Integration, Architecture
Lead Mobile Engineer
2023 - 2023
Wash - Main
- Led a large team to iterate on a new version of a mobile app to bring a better system to hundreds of thousands of users.
- Took over the UI/UX processes for white labelled applications used by US Universities.
- Developed a complex mobile-first analytics dashboard to be used by the sales team.
Technologies: React Native, Figma, User Interface (UI), User Experience (UX), API Integration, Architecture
Full-stack Developer
2022 - 2023
Duda & Moon, LLC
- Scraped US charitable organizations, storing millions of queryable records by a flexible variety of filters with minimal processing time.
- Redesigned the UI and UX for a product and implemented new designs.
- Oversaw the release of the product through the first phase of external testing.
Technologies: React, TypeScript, PostgreSQL, Google Cloud Platform (GCP), ETL, Figma, User Interface (UI), User Experience (UX), Compliance, Architecture
Lead Senior Full-stack Engineer
2020 - 2023
Pinkaloo
- Led internal projects for the creation of a development portal to facilitate API access, as well as the development of an embeddable widget to transport functionality. Done with Node.js and GatsbyJS.
- Acted as a full-stack engineer on the core project. Developed and enhanced core features while coordinating several engineers.
- Refactored React front end from Redux and Class components to React Query and functional components.
- Reverse-engineered and migrated the Django admin portal to React/Node.js.
Technologies: React, Node.js, CI/CD Pipelines, Regulated Industries, Compliance, Architecture
Mobile Lead
2022 - 2022
Nuro Inc - Main
- Developed an Uber Eats-style app for a major AI company to hail autonomous delivery bots.
- Used Geo fencing to limit mobile reach for hailing vehicles.
- Improved security and development flow, increasing productivity immensely.
Technologies: React Native, Figma, User Interface (UI), User Experience (UX), Compliance, Architecture
React Native Developer
2022 - 2022
Life's SoGood, Inc.
- Helped bring a React Native app over the finish line by adding streaming capability.
- Built a Twitch-style mobile app for streaming shoppable content to thousands.
- Refined implementation and UI/UX flow creation throughout the app, both programmatically and through Figma.
Technologies: React Native, Node.js, User Experience (UX), User Interface (UI), Figma, MongoDB, Architecture
Lead Full-stack Developer
2021 - 2022
Volvo Car USA - Data Management and Insights Team
- Developed complex tooling and dashboard for delivering marketing insights and analytics to the marketing team.
- Refactored a Kubernetes cluster and Python code to a more maintainable and manageable service with zero downtime.
- Implemented complex queries to datalake to aggregate user reports and data.
- Developed customer mobile app reaching thousands for vehicle-order leads.
Technologies: JavaScript, SQL, Azure, CI/CD Pipelines, NoSQL, Amazon Web Services (AWS), Kubernetes, Compliance, Architecture
Tech Lead
2021 - 2022
Surgiyo
- Led a Toptal project composed of an entire team to create a compliant app for the surgical field.
- Advised and enforced HIPAA compliance throughout all aspects of the application.
- Leveraged native streaming and downloading to create a TikTok-style experience.
Technologies: Firebase, Google Cloud Platform (GCP), Serverless Architecture, DevOps, HIPAA Compliance, Regulated Industries, Compliance, Architecture
Senior React Developer
2021 - 2022
italyMONDO! LLC
- Utilized Gatsby experience to guide a project and its developers to perfection.
- Achieved perfect Gatsby accessibility, SEO, and rendering scores.
- Leveraged minimum hours to achieve maximum output for clients.
Technologies: TypeScript, React, Architecture
CTO | Engineering Lead
2020 - 2022
Everloom
- Defined the entire engineering process to development, deployment, hiring, and demo.
- Provided engineering, product, and release strategy consultation for the company.
- Managed and mentored other junior developers, as well as delegated tasks and distributed teams.
Technologies: React, Node.js, Express.js, Amazon Web Services (AWS), Architecture
Lead Developer
2021 - 2021
Techology Inc.
- Aided an existing team in transitioning from a template POC to a full tech stack designed to scale.
- Aided in hiring efforts to produce a capable team.
- Advised on HIPAA and general healthcare requirements for elderly care homes in Los Angeles.
Technologies: JavaScript, TypeScript, React, Node.js, Google Cloud Platform (GCP), HIPAA Compliance, Architecture
Freelance Software Engineer
2021 - 2021
- Remastered an old internal tool from an old adaptation of React to use new and relevant tools.
- Contributed full-stack code to a massive system within two days of working there.
- Developed with familiar technologies like React and GraphQL and unfamiliar ones like PHP proficiently with minimal onboarding time.
Technologies: React, GraphQL
Engineering Consultant | Developer
2021 - 2021
Levade
- Redesigned the whole internal engineering process for the company.
- Hired junior engineers and delegated tasks in line with their individual skills. Acted as a mentor, QA, and PR.
- Provided internal product, engineering, and release strategy consulting.
- Built admin dashboard for user stats compilation with Django.
Technologies: React Native, Google Cloud Platform (GCP), Node.js, CI/CD Pipelines
Engineering Consultant
2020 - 2021
Recover Athletics Inc.
- Provided improved development flow and code assessment for existing applications, leading to the acquisition by Strava.
- Worked on the development of React Native application with several microservice back ends.
- Provided mentorship for other developers and general software process consulting for the company.
Technologies: React Native, Node.js
Engineering Project Lead
2019 - 2021
California Polytechnic State University
- Developed an equipment reservation and test-taking system for a state university engineering department to allow students and faculty to obtain the qualification and reserve lab equipment.
- Built using GCP for the full environment while staying standard with state regulations for software.
- Managed and built the development process, deployment strategy, and product pipeline. Wrote code for all aspects.
- Designed the first round of UI and UX for the product and later contributed to the redesign.
Technologies: Angular, Node.js, Firebase, Ionic
Senior Front-end Engineer
2020 - 2020
Alius Health, LLC
- Enhanced web design and responsiveness to create a more seamless user experience.
- Migrated the front end to a mobile-first implementation through the creation of high-fidelity mobile designs and implementation.
- Upgraded deprecated packages to create a more modern application.
Technologies: React, C#, HIPAA Compliance
Mobile Engineer
2020 - 2020
Lyra Entertainment
- Worked on the core listening functionality of the music streaming application.
- Created major features like playback, complex queue, and playlist management.
- Adjusted native iOS SDKs to suit personal needs and hired and managed help for the Android side.
- Created deployment pipeline for internal testing and external release.
Technologies: React Native, CI/CD Pipelines, iOS
Mobile Engineer
2020 - 2020
Scionian
- Worked on developing an AI assistant for the University of Southern California.
- Implemented development lifecycle flow for upgrading, deploying, and managing applications.
- Split job over several months based on incoming requirements.
Technologies: React Native, Expo, Node.js, Amazon Web Services (AWS), React
Senior Mobile Engineer
2020 - 2020
Brandibble Co
- Reverse-engineered the web app single-handedly to create a mobile app using common Redux and JavaScript custom libraries.
- Built a configurable app for individual sales to restaurants.
- Worked closely with product and design to ensure a flawless reproduction of the web version while also adjusting the design to accommodate mobile best practices.
Technologies: JavaScript, TypeScript, React, Android, iOS, Expo, React Native
Senior Full-stack Developer
2020 - 2020
Spin Master
- Hired to alleviate strain involved in creating middleware to connect the CMS (Contentful) and the front end (GatsbyJS) through a mapping Node.js server as well as to help develop the front end.
- Worked with a large team and coordinated over many sides of the project, specifically the front and back end, CMS, and DevOps.
- Worked on the major Spin Master account through the company ThrillWorks.
Technologies: GraphQL, Node.js, React
CTO | Lead Developer
2019 - 2020
Esports Fantasy
- Developed an app to target a community of gamers who enjoy fantasy sports. Built a league-based system that runs real-time drafts, contests, and rankings for a community of gamers.
- Developed the architecture and MVP for the product singlehandedly using GCP, Firebase, Ionic for iOS and Android, and Django.
- Brought the product across the finish line, deployed it, and managed updates.
- Built internal dashboard for logging player statistics into a drafting system with Django.
Technologies: Kubernetes, PostgreSQL, GraphQL, Node.js, JavaScript, React Native
Engineering Project Lead
2019 - 2020
Dolby Laboratories
- Built a marketing platform for a major enterprise using React and Gatsby.
- Created v1 as a solo lead developer, defining the stack and architecture. Built v2 with an overseas team as a lead developer.
- Composed documentation using JAMstack and developed a portal to sell API usage using Apigee.
Technologies: Node.js, GraphQL, React, Google Cloud Platform (GCP)
Lead Senior Full-stack Engineer
2019 - 2020
First Mark
- Led and managed all matters of technology and development for the corporate SaaS company during time there.
- Built an Ionic-based mobile app using Ionic 4 and Angular 8 with a Node.js back end.
- Developed an Angular 8-based desktop app to govern content and users on an app.
- Create a billing system based on mobile and desktop usage and powered by Stripe.
- Had a strong hand in the UI/UX and product design.
- Developed a system to manage time tracking and onboarding in the film industry.
Technologies: Amazon Web Services (AWS), Figma, Express.js, Node.js, Angular, Ionic
Senior Full-stack Developer
2019 - 2019
Memory Beach
- Upgraded an existing project to the newest technology. Upgraded framework dependencies that were nearly a decade old.
- Produced statistics and gleaned data from CSV sheets created by the content author.
- Improved the workflow and set up a development system while standardizing processes for future developers.
Technologies: Angular, Ionic
Lead Engineer
2019 - 2019
Grid Cell
- Built a product to help keep track of various hazards and information in buildings while inspectors analyze a new building.
- Developed an MVP from start to finish singlehandedly.
- Produced a metric-based PDF data sheet from the in-app data using Handsontable.
Technologies: Amazon Web Services (AWS), Google Maps API, Ionic
Engineering Lead | Developer
2019 - 2019
Cvent
- Architected and developed an app for a large enterprise.
- Created a product that allows large gatherings of people to photograph, mark up, and edit images to be shared across several platforms, like Snapchat for companies.
- Conformed security standards to Cvent standards, and brought product across the finish line.
- Scaled out an old project base to enhance and finalize the project for an enterprise-level solution (Cvent).
- Reverse-engineered and scaled out a Vanilla JavaScript and PHP system with third-party integrations like Salesforce, Pardot, and SendGrid.
- Took the project, which had been in a queue for several months, and brought it over the finish line with an effective delivery and deployment solution.
Technologies: Android, iOS, Node.js, React Native, JavaScript
Ionic Mobile Developer
2019 - 2019
App Presser
- Developed Ionic mobile apps from start to finish on behalf of several clients.
- Took over Ionic mobile apps to bring them across the finish line.
- Worked in many small teams to deliver several products at the same time.
Technologies: Firebase
Lead Front-end Engineer
2018 - 2019
Gizer Gaming
- Developed the full application, which hosted 10,000 users from start to finish.
- Integrated Branch.io, OneSignal, SendGrid, and the full Firebase Suite.
- Involved in the design implementation of the in-app currency and experience point system protected by Ethereum.
- Collaborated intensely with UI/UX designers to implement a complex vision.
Technologies: Node.js, Firebase, Angular
Lead Full-stack Engineer
2017 - 2018
Tally Interactive
- Integrated a custom video call-in solution that was used to stream a five-person video call to a custom CDN.
- Managed a low-latency video stream, syncing it with live prompts.
- Produced a custom CDN to manipulate a video feed emitted from a client before redirecting it to popular streaming platforms with NGINX.
- Assisted with product management and UI/UX design.
- Integrated Branch.io, OneSignal, SendGrid, and the full Firebase Suite.
Technologies: Amazon Web Services (AWS), Firebase, React, React Native
Experience
Chromie Health
I developed an AI Nurse Dispatch platform, aiding hospitals in tracking nurse attendance and issuing intelligent dispatches to ensure filled slots and cost savings throughout the process. This product, which directly serves hospitals, leverages AI to address the current nursing shortage crisis in the US.
Skills
Libraries/APIs
Node.js, React, REST APIs, Google Maps API
Tools
Expo, Figma, Blender, Claude Code
Languages
TypeScript, JavaScript, GraphQL, SQL, C#
Frameworks
Ionic, Express.js, Angular, React Native, NestJS, Blend4Web, Next.js, Photon
Paradigms
Serverless Architecture, DevOps, HIPAA Compliance, ETL, Mobile Development
Platforms
Firebase, Android, iOS, Google Cloud Platform (GCP), Amazon Web Services (AWS), Kubernetes, Tezos, Blockchain, Azure, MacOS, Twilio
Storage
NoSQL, PostgreSQL, MongoDB, Database Architecture
Other
Artificial Intelligence (AI), Full-stack Development, OpenAI, CTO, Gaming, Technical Leadership, APIs, Mobile App Development, Retrieval-augmented Generation (RAG), Architecture, Fractional CTO, Agentic AI, API Integration, CI/CD Pipelines, User Interface (UI), User Experience (UX), Web3, Blockchain Architecture, Regulated Industries, Compliance, Full-stack, Web Development, RAG Systems, Large Language Models (LLMs), Embeddings from Language Models (ELMo), SMS
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