Haymi Gulersen Barokas
Verified Expert in Engineering
Full-stack Developer
Haymi is a full-stack developer bringing business vision to life using technology. He has seven years of enterprise experience in industry-leading companies such as Facebook and Coca-Cola, as well as in bootstrapping a startup on the side with limited resources. Aside from his technical proficiency, Haymi pays great attention to clients to understand their ultimate goals and perform his work accordingly.
Portfolio
Experience
Availability
Preferred Environment
React, React Native, Hack, PHP, JavaScript, Python, GraphQL, SQL, Haskell, Tailwind CSS
The most amazing...
...product I've built is a mobile application in React Native, Node.js, GraphQL, and PostgreSQL as my side project.
Work Experience
Co-founder and Developer
Sanamekan
- Developed the iOS and Android mobile apps in React Native to enable people to find extraordinary venues for their events. The back-end stack consisted of Node.js, GraphQL, PostgreSQL, and Meilisearch.
- Migrated the web application from WordPress to Next.js.
- Debugged full-stack production issues such as slowness and outdated dependencies.
Full-stack Engineer
Monad Inc.
- Rewrote existing data extraction logic in a highly parallelized manner. Achieved a 2,000 faster extraction overall. Deployed the solution production for the biggest paying customer.
- Wrote a Databricks integration to extract data from Redshift to Databricks in a scalable manner using Singer and streaming.
- Participated actively in the on-call rotation and debugged and resolved critical production bugs.
- Led proofs of concept to migrate a legacy data ingestion model to Apache Spark and structured streaming.
Full-stack Production Engineer
- Contributed to a full-stack internal web application to reduce the operational load for data center employees and orchestrate the lifecycle of servers via automation.
- Participated in an on-call rotation to mitigate critical production issues as quickly as possible.
- Met with XFN partners regularly to understand business needs, helped them prioritize by assessing impact vs. effort, and landed features to make them more efficient by reducing manual work.
Automation Developer
- Identified signals of malicious behavior through data analysis and crafted automation to tackle abuse vectors.
- Improved internal tools to reduce time spent and to increase quality in human reviews.
- Acted as a tech lead within the team by mentoring peers in system design, aided in debugging production issues, and connected them with relevant stakeholders to unblock their projects.
- Built data pipelines to collate data spread out and turned it into actionable insights with data visualization. Enabled business people to build processes around these insights.
Business Analyst
Coca-Cola
- Led a project to consolidate five different region-wide instances into a single streamlined tool within Eurasia and Africa, reducing the yearly support costs by 80%.
- Served as a bridge between businesses and developers by gathering requirements and running user acceptance testing.
- Oversaw the software support process by tracking key metrics such as turnaround time, resolution time, and quality.
Experience
React Native App for Sanamekan
I built the whole technical stack, including the back end and front end. For the back end, I used Node.js, PostgreSQL, and Strapi as CMS, and I also implemented Meilisearch, similar to ElasticSearch, to enable rapid search for the users in the app. By leveraging WebSocket, I built real-time features from scratch, such as in-app chat without third-party tools due to a tight budget.
Automation and Data Analysis Project
I ran sessions with stakeholders to get feedback and then continued iterating on it. Eventually, we built a whole operational flow around this dashboard, reducing the abuse areas we monitored considerably.
Migration of Sanamekan's WordPress Web App to Next.js
• migrating core WordPress SQL tables to PostgreSQL;
• building the back end in Node.js and the API in GraphQL;
• creating a script to migrate static files such as images into a new server;
• redesigning the look and feel and rewriting the front end in Next.js.
Data Center Web App and Automation
API Integration with Security Tools
The key challenge addressed was the diversity of data formats across different tools. By leveraging Python and SQL, the project implemented data transformation processes that converted disparate data into a uniform structure. This standardized data was then exported to a data warehouse, enabling efficient storage, analysis, and reporting.
The outcome was a streamlined and automated workflow that enhanced the ability to analyze security data across tools, providing comprehensive insights into the security posture and facilitating informed decision-making.
Skillset
Languages
JavaScript, Python, GraphQL, SQL, TypeScript, Hack, PHP, HTML, CSS, Haskell, Swift, Python 3, Snowflake
Frameworks
React Native, Next.js, Tailwind CSS, JSON Web Tokens (JWT), Selenium, Jest, Laravel, Apache Spark, Express.js
Libraries/APIs
React, Node.js, Socket.IO, REST APIs, MobX, React Native for Web
Tools
Expo.io, Expo, Flow, JSX, Git, NGINX, Figma, Pytest
Paradigms
Mobile Development, Object-oriented Programming (OOP), App Development, Automation, User Acceptance Testing (UAT), ETL, Search Engine Optimization (SEO)
Platforms
Amazon Web Services (AWS), Mobile, WordPress, iOS, Android, Docker, Kubernetes, Databricks
Other
Debugging, Web Development, Interviewing, Code Review, Technical Hiring, Source Code Review, Task Analysis, Mobile Applications, Mobile Apps, Single-page Applications (SPA), Strapi, Data Transformation, API Integration, Scripting, APIs, Responsive Web Apps, Full-stack, Back-end, Minimum Viable Product (MVP), Front-end, Scraping, App Store, FastAPI, Zustand, Supabase, Software Project Management, WebSockets, Apollo, Monorepos, Prefect, Data Warehouse Design, ELT, ETL Testing, Singer ETL, Google Play Console, Data Build Tool (dbt)
Storage
PostgreSQL, Data Pipelines, Databases, MySQL, MongoDB, NoSQL, Redshift
Education
Bachelor's Degree in Mechanical Engineering
Istanbul Technical University - Istanbul, Turkey
How to Work with Toptal
Toptal matches you directly with global industry experts from our network in hours—not weeks or months.
Share your needs
Choose your talent
Start your risk-free talent trial
Top talent is in high demand.
Start hiring