Filip is available for hire
Hire FilipFilip Szymański
Verified Expert in Engineering
Software Developer
Rzepin, Poland
Toptal member since July 1, 2022
Bio
Filip wrote his first code at 13 and has been going down the rabbit hole ever since. He loves taking part in creating innovative products that make an impact and solving engineering challenges along the way. In those few years, he has experimented with many technologies, including front end, back end, security, gaming, and some parts of mobile. Filip has self-started a vast amount of projects and is a self-organized, detail-oriented professional.
Portfolio
idora.ai
TypeScript, Node.js, Rust, OpenAI, Agentic AI, LangChain, Architecture, Docker...
B WYNN SPORTS LLC
Web Scraping, JavaScript, React, Node.js, Python, Amazon Web Services (AWS)...
Box
PHP, Jenkins, Software Architecture, Apache Kafka, Cloud Architecture...
Experience
- Back-end - 6 years
- PHP - 6 years
- Node.js - 5 years
- TypeScript - 5 years
- JavaScript - 5 years
- Symfony - 5 years
- NestJS - 5 years
- REST - 5 years
Preferred Environment
Node.js, TypeScript, Docker, PHP, Back-end, NestJS, GitHub, Symfony, SQL, API Development, Grafana k6, Prisma
The most amazing...
...thing I did was founding an RPG from scratch that later placed in the top 10 in Western Europe.
Work Experience
Software Architect | Engineering Lead
2025 - 2025
idora.ai
- Designed and implemented the entire system in NestJS and a microservice architecture - a layer of governance for complex logic pipelines.
- Built a high-availability architecture with horizontal scaling, polyglot persistence, high observability, and telemetry pipelines to support complex LLM- and code-driven workflows.
- Recruited and built the engineering team from scratch.
- Created an environment for safe code-driven workflows in Rust, ensuring both low latency and a high level of isolation, with a lot of inspiration from AWS Lambda-powered workflows.
Technologies: TypeScript, Node.js, Rust, OpenAI, Agentic AI, LangChain, Architecture, Docker, AWS Lambda, AI-generated Code, Software Design, CTO
Full-stack Developer
2025 - 2025
B WYNN SPORTS LLC
- Developed a high-scale web scraping solution in Nest.js for collecting content from YouTube, Instagram, and TikTok, handling 50,000+ media assets every three hours.
- Implemented a custom load balancer to manage ISP proxies, improve request distribution, and reduce scraping failures.
- Built advanced health metrics and monitoring dashboards to track scraper success rate, application performance, and system reliability.
- Deployed and orchestrated the entire solution in a bare metal environment, ensuring scalability, high availability, and cost efficiency for over 300 runners.
Technologies: Web Scraping, JavaScript, React, Node.js, Python, Amazon Web Services (AWS), Architecture, Docker, AI-generated Code, Software Design, CTO
Software Engineer III
2024 - 2025
Box
- Worked in the monolith foundation team (core team for monolith) for a large-scale application operating over 500 million requests per month.
- Developed internal technical tools used by over 3,000 developers.
- Conducted the migration of a large-scale Jenkins controller to a self-managed alternative on GCP, improving reliability and reducing operational costs by tens of thousands of dollars.
- Resolved critical technical vulnerabilities, contributing to the successful attainment of FedRAMP High certification.
Technologies: PHP, Jenkins, Software Architecture, Apache Kafka, Cloud Architecture, Distributed Systems, Grafana k6, Code Refactoring, Refactoring, AI Agents, RPC, Stripe, Agentic AI, FastAPI, Architecture, Docker, AI-generated Code, Software Design
Senior Back-end Engineer
2024 - 2025
PepsiCo
- Developed an app that simplifies product management and digital ordering, and have been present in over 30 geographies for large-scale customers.
- Tracked and fixed many bugs in the large monolithic application using Azure DevOps.
- Developed many development tools to improve the quality of the codebase and took the initiative to introduce health monitoring of multiple CRON jobs for advanced business flows.
- Refactored many parts of legacy code and collaborated with different pods to ensure better quality of the created code.
- Collaborated with software stakeholders and suggested many possible technical improvements or redefined requirements.
Technologies: PHP, Object-oriented Programming (OOP), SQL, Azure, Pimcore, GraphQL, Symphony, Software Architecture, Apache Kafka, Cloud Architecture, Code Refactoring, Refactoring, RPC, Architecture, AI-generated Code
Lead Software Engineer/Architect
2018 - 2025
devGaming
- Led back-end/client architecture and development in Node.js/TypeScript/Nest.js with REST/gRPC microservices. Conducted a refactor to the newer engine.
- Wrote tons of anti-cheat, abuse prevention, and monitoring measures, which resulted in a detection rate over 95% for 3 million sessions and 250,000 players.
- Profiled and improved performance in critical areas to avoid latency spikes.
- Built and supervised a remote team of up to 20 engineers divided into three teams (back end, gameserver, gameclient).
- Designed a secure flow of UDP packet encryption between client and server from scratch.
- Identified issues ripe for automation, which reduced support inquiries by 90%.
Technologies: Node.js, Amazon Web Services (AWS), .NET, PHP, Lua, SQL, Linux, Kubernetes, NestJS, Symfony, Microservices, TypeScript, JavaScript, Preact, React, Architecture, Custom CMS Development, MariaDB, Parsers, Web Scraping, API Integration, Object-oriented Programming (OOP), Symphony, HTML5, Startups, Minimum Viable Product (MVP), Software Architecture, Full-stack Development, Cloud Architecture, Prisma, Code Refactoring, Refactoring, Automated Testing, RPC, Stripe, Agentic AI, CTO
Senior Back-end Engineer
2024 - 2024
STS
- Refactored a CI/CD flow, which resulted in a 200% faster build and deployment time.
- Contributed to the financial API operating with over 15 million monthly payments.
- Refactored a big part of the internal tool for the financial operations team.
Technologies: PHP, Node.js, Go, Symfony, Google Cloud Platform (GCP), Kubernetes, Docker, Python, Data Scraping, Apache Kafka, Cloud Architecture, Prisma, Code Refactoring, Refactoring, Stripe, Amazon Web Services (AWS)
Back-end Engineer
2022 - 2023
Ramp Network
- Implemented new features for a cryptocurrency swap platform, including blockchain operations or integrations with exchanges.
- Worked in a core blockchain treasury team and was responsible for integrating exchanges and processing blockchain operations (in-ramp and off-ramp).
- Designed a consistent flow for handling storage buckets for static and dynamic environments.
- Implemented an integration with a platform that helps with asset management.
- Wrote a big part of the liquidity module, including automatic treasury supply.
Technologies: Node.js, NestJS, PostgreSQL, Docker, TypeORM, Blockchain, SQL, Design Patterns, Unit Testing, API Development, API Integration, Object-oriented Programming (OOP), Startups, Minimum Viable Product (MVP), Apache Kafka, Prisma, Refactoring, Crypto
Senior Back-end Engineer
2022 - 2023
Ready4S
- Worked on a platform for course management with the zero technical debt principle.
- Worked on core solutions from the first sprints of a platform lifecycle.
- Managed to constantly be ahead of time with feature and bug-free solution delivery.
- Reduced coupling of modules in a large app by using CQRS for common parts.
- Implemented flow for bidirectional integration and aggregation of data coming from external data sources.
Technologies: PHP, Symfony, PostgreSQL, Docker, Architecture, APIs, GitHub, REST APIs, Web Development, PHPUnit, E2E Testing, CSS, Twig, SQL, PHP 7, Design Patterns, Unit Testing, API Development, Parsers, API Integration, Object-oriented Programming (OOP), Symphony, React Native, iOS
Back-end Engineer
2021 - 2022
IngeniousIO Inc.
- Participated in developing one of the biggest applications in the AECO industry.
- Improved data consistency and relations between modules.
- Improved the quality of the QA team by implementing tests using Insomnia, which resulted in a reduction of bugs occurring in the production environment.
Technologies: PHP, Laravel 5, Docker, PostgreSQL, MongoDB, Redis, Architecture, APIs, GitHub, REST APIs, Web Development, Laravel, PHPUnit, E2E Testing, CSS, Twig, MySQL, SQL, PHP 7, Design Patterns, Unit Testing, API Development, API Integration, Object-oriented Programming (OOP), Symphony, Startups, Chatbots, React Native, iOS
Freelance Software Engineer
2017 - 2022
Freelance
- Delivered a mobile application (NFC personal card for F1 Racing Driver) with a dedicated back-end solution. Received uplifting recommendations for excellent, smooth, and bug-free delivery.
- Designed a system for managing eCommerce from scratch and integrated it with the biggest marketplace in Poland. Ensured almost 100% uptime and was processing nearly 100,000 offers each week.
- Designed an RPG that became the biggest in Poland and handled peaks of hundreds of players simultaneously in the game and thousands on the web.
- Created a solution for real-time log managing from huge input.
- Created utility apps for Windows in C#, .NET, WPF, and other tools.
Technologies: Node.js, PHP, Flutter, JavaScript, TypeScript, Git, Symfony, PostgreSQL, MySQL, MongoDB, Web Security, NestJS, APIs, Ajax, Firebase, Google Cloud Platform (GCP), GitHub, REST APIs, Web Development, Laravel, GraphQL, Amazon Web Services (AWS), PHPUnit, E2E Testing, CSS, Twig, Charts, Laravel 5, SQL, HTML, PHP 7, Design Patterns, Unit Testing, API Development, React, API Integration, Object-oriented Programming (OOP), Python, HTML5, Appointment Booking, Prompt Engineering, ChatGPT, AI Chatbots, Chatbots, React Native, iOS, Full-stack Development, Agentic AI, Large Language Models (LLMs)
Full-stack Engineer
2019 - 2021
IT9
- Developed a tax return management application from scratch according to a self-designed architecture proposal.
- Operated with the Scrum methodology in close cooperation with product owners and project managers.
- Performed code reviews for other team members according to the clean code and SOLID principles.
- Developed the front end and back end for the tax-tech solution.
- Identified issues ripe for automation, which reduced required user interactions.
- Sped up the algorithm of parsing an input from O(n3) to O(n) complexity.
- Implemented a flow to automatically bootstrap (feature flagging) and ensure CI/CD for multi-tenant applications that had dozens of tenants.
- Enhanced a feature flagging idea by isolating core from domain logic by splitting logic into injectable plugins to safely share codebase with on-premise clients.
Technologies: PHP, Symfony, Back-end, Architecture, NestJS, APIs, Laravel, CSS, Full-stack, MySQL, PHP 7, Design Patterns, Unit Testing, API Development, PHP MVC, CoreUI, Web Scraping, API Integration, Object-oriented Programming (OOP), Symphony, Python, HTML5, iOS, Full-stack Development
Experience
WirePool Finance
Developed a solution for a blockchain platform that allows creating stake pools for every asset on earth, distributing shares, and earning from them.
The platform provides tokenization of assets, apps, passive income, and raising capital for further investments. The project was suspended due to the lack of time.
The platform provides tokenization of assets, apps, passive income, and raising capital for further investments. The project was suspended due to the lack of time.
Amployed | Niche Job Boards Network
https://amployed.ioI designed a scalable web solution for an online job board network based on Node.js with the Nest.js framework using a PostgreSQL database. The system allows launching a job board for another industry in less than one day based on the same source code through advanced configuration and feature flags.
I created configurable and scalable software to bootstrap advanced job boards in less than a day. I developed a scalable RESTful API using Node.js/Nest.js with high efficiency and security in mind.
The biggest challenge during coding was the matching algorithm, which, based on the data filled in by the candidate, would find relevant jobs that matched the candidate's skills and display a percentage match rate.
I created configurable and scalable software to bootstrap advanced job boards in less than a day. I developed a scalable RESTful API using Node.js/Nest.js with high efficiency and security in mind.
The biggest challenge during coding was the matching algorithm, which, based on the data filled in by the candidate, would find relevant jobs that matched the candidate's skills and display a percentage match rate.
Allegro Integrator
I designed and implemented an application that seamlessly integrated the largest marketplace in Poland and Europe with a dropshipping platform. The application was designed to scrap offers from the API in real-time. I used low-latency message brokers such as MQTT to ensure fluent communication between microservices.
Qrisk
• Founded the platform to help car rental companies verify their customers, a bit similar to scoring in the banking industry.
• Led the back and front-end delivery process and wrote the core part of the solution with effectiveness and security in mind.
• Integrated over a dozen external data sources that aggregate data into one report about the client.
• Ensured cryptographic security for given personal data and implemented a lot of factors to store data as safely as possible.
• Led the back and front-end delivery process and wrote the core part of the solution with effectiveness and security in mind.
• Integrated over a dozen external data sources that aggregate data into one report about the client.
• Ensured cryptographic security for given personal data and implemented a lot of factors to store data as safely as possible.
Discord Bot For Sportbook Odds
A C#-based bot for monitoring odds divergencies between multiple US-based sportbooks to advertise profitable bets for users. Utilized multiple data sources to ensure high quality and consistency of data and ensured almost 100% uptime. Introduced external data consistency checks and developed many metrics to make the output as precise as possible.
Certifications
JANUARY 2023 - PRESENT
JavaScript Assessment Badge
JUNE 2022 - PRESENT
Certified Node.js Engineer
TripIebyte
APRIL 2022 - PRESENT
Certified Back-end Engineer
TripIebyte
APRIL 2022 - PRESENT
Certified Algorithms/Data Structures Engineer
TripIebyte
FEBRUARY 2021 - PRESENT
Certified JavaScript Engineer
TripIebyte
Skills
Libraries/APIs
Node.js, Stripe, REST APIs, React, API Development, Preact, Leaflet, DirectX, React Query, Discord.js, Playwright
Tools
Prisma, Git, GitHub, ChatGPT, Grafana k6, RabbitMQ, Sentry, Apache, Jenkins
Languages
TypeScript, PHP, JavaScript, Lua, HTML, CSS, PHP 7, Python, HTML5, GraphQL, SQL, Go, Rust
Frameworks
Symfony, NestJS, Twig, PHP MVC, Laravel 5, Express.js, Laravel, PHPUnit, React Native, Flutter, Next.js, .NET
Paradigms
REST, Object-oriented Programming (OOP), Code Refactoring, Refactoring, Microservices, E2E Testing, Unit Testing, Automated Testing, Design Patterns
Platforms
Docker, Kubernetes, Apache Kafka, Firebase, Amazon Web Services (AWS), Google Cloud Platform (GCP), Blockchain, Linux, Azure, Pimcore, iOS, AWS Lambda
Storage
PostgreSQL, Databases, Database Management, MySQL, MongoDB, Redis, MariaDB
Other
Back-end, Architecture, APIs, Web Development, Integration, Parsers, Web Scraping, API Integration, Symphony, Large Language Models (LLMs), Startups, Chatbots, Data Scraping, Software Architecture, Full-stack Development, Cloud Architecture, Distributed Systems, Back-end Development, Crypto, Agentic AI, Software Design, Web Security, Ajax, Document Parsing, Full-stack, TypeORM, Discord, Discord Bots, Algorithms, Brokers, Artificial Intelligence (AI), Appointment Booking, Prompt Engineering, AI Chatbots, Minimum Viable Product (MVP), Scheduling, AI Agents, FastAPI, AI-generated Code, CTO, Shaders, Amazon RDS, eCommerce, Charts, Enqueue, Data Structures, Chakra UI, CoreUI, Custom CMS Development, Front-end, Cryptography, Discord.py, RPC, OpenAI, LangChain
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