Denis Tola
Verified Expert in Engineering
Software Engineer and Full-stack Developer
Berlin, Germany
Toptal member since March 3, 2026
Denis is a senior software engineer who designs and runs reliable systems end to end. Working at the intersection of data, infrastructure, and product engineering, he builds scalable architectures, automates complexity, and keeps systems stable under real-world load. Denis takes ownership from architecture to deployment, improves performance and observability, and creates tooling that removes friction for teams while delivering software that is correct, maintainable, and built to last.
Portfolio
Experience
- Python 3 - 8 years
- SQL - 6 years
- Django - 6 years
- React - 5 years
- TypeScript - 5 years
- Amazon Web Services (AWS) - 5 years
- FastAPI - 4 years
- Next.js - 4 years
Preferred Environment
Python 3, TypeScript, FastAPI, Django, Next.js, React, JavaScript, Node.js, SQL, Amazon Web Services (AWS)
The most amazing...
...project I've directed migrated a legacy platform to cloud native infrastructure without service interruption.
Work Experience
Tech Lead
South Pole
- Owned architecture and end-to-end delivery of Python/FastAPI, TypeScript/NextJS, Postgres, and GCP.
- Led cloud-native and event-driven architecture using GKE, Cloud SQL, Pub/Sub, Redis, and containerized services.
- Drove platform initiatives across authentication, multi-tenancy, security, observability, reliability, and CI/CD.
- Set technical direction and engineering standards, review implementations, and support other engineers.
- Partnered with product and climate-risk specialists to translate complex domain requirements into scalable production systems.
- Built data and AI capabilities using Snowflake and Snowflake Cortex for analytics, data processing, and AI-powered workflows.
Full-stack Developer
Samuel Rahbarifar
- Architected and deployed a production Voice AI platform on AWS using OpenAI Realtime, Deepgram, ElevenLabs, Retell AI, FastAPI, PostgreSQL, Redis, and Qdrant for real-time patient and clinic workflows.
- Built GitHub Actions CI/CD with unit and integration tests, release validation, Docker builds, and environment promotion across dev, staging, and production on AWS, with health checks and controlled rollouts.
- Owned production reliability using structured logging, Sentry, CloudWatch, health checks, alerts, retries, fallbacks, and rollback procedures across AI agents, FastAPI services, telephony, and external clinic APIs.
- Managed agent lifecycle with Git-versioned prompts and configuration, release validation, monitoring, rollback, provider fallbacks, and guarded tool execution for scheduling, patient lookup, SMS, and clinic workflows.
- Built persistent agent memory using embeddings, Qdrant vector search, and RAG to retrieve user-specific context across conversations and inject relevant memories into voice AI sessions for personalized interactions.
Senior Software Engineer
Blocks
- Built and optimized large-scale data platforms using Apache Iceberg, Spark, Polars, Trino, and ClickHouse, enabling fast, reliable processing of multi-terabyte datasets.
- Designed and maintained Airflow orchestration for complex ETL pipelines, improving data throughput, failure recovery, and end-to-end observability.
- Developed back-end services and internal automation tools in Python, deployed on Amazon Elastic Container Service (ECS), and managed infrastructure via Terraform for consistent, reproducible environments.
- Implemented FinOps systems for commitment modeling, AWS Cost and Usage Reports (CUR) processing, and savings-plan optimization.
- Architected dashboards and internal UIs using Next.js to surface analytics.
Senior Software Engineer
Wavecrest
- Developed and optimized high-performance web applications using Python (FastAPI), Next.js, and PostgreSQL, ensuring scalability and reducing response times.
- Enhanced GraphQL data fetching efficiency by implementing Redis caching, significantly improving response times.
- Streamlined data processing with Pandas and NumPy, improving analytics and decision-making capabilities.
- Integrated Celery for asynchronous task execution, reducing API latency and improving system reliability.
- Implemented test-driven development (TDD), CI/CD pipelines, and Docker, ensuring robust, secure, and automated deployments.
Senior Full-stack Developer
Trendlab
- Developed and deployed predictive market trend models using Python, leveraging Pandas, NumPy, and Scikit-learn to enhance forecasting accuracy and support data-driven decision-making.
- Designed and implemented a scalable data pipeline, integrating web scraping techniques with Beautiful Soup and Selenium to gather real-time market insights.
- Processed and analyzed datasets using Pandas and Kafka, enabling real-time trend detection and decision-making.
- Built RESTful APIs with Django to expose market analysis insights to clients and internal teams.
- Optimized database performance by leveraging PostgreSQL and Elasticsearch for efficient data storage and retrieval.
- Integrated Celery-based task scheduling for continuous data aggregation and report updates, ensuring up-to-date insights.
- Implemented CI/CD pipelines with Docker, streamlining deployments and improving system reliability.
Full-stack Developer
BetSport
- Built and scaled a Django and React betting platform supporting more than 10,000 concurrent users with real-time odds, bet processing, and WebSocket notifications.
- Designed RESTful APIs and optimized PostgreSQL and MongoDB databases.
- Integrated secure 3rd-party payment systems and implemented automated testing with Pytest.
- Automated deployments with CI/CD pipelines, ensuring fast, reliable releases.
Software Engineer
BMW
- Improved ISTA/D and ISTA/P diagnostics, integrating CAN bus protocols for faster troubleshooting.
- Enabled over-the-air (OTA) updates with Python and secure frameworks for BMW's connected cars.
- Built diagnostic algorithms using FlexRay and Ethernet for advanced driver-assistance systems (ADAS) and hybrid systems.
Experience
Lighthouse
https://github.com/Eaglemann/aws-lighthouseCommitgen-cc
Time-travel Crypto-trading Engine
https://github.com/Eaglemann/Time-Travel-Crypto-Trading-EngineSchema Sense CSV to SQL
https://github.com/Eaglemann/Schema-Sense-CSVtoSQLAskPDF CLI
https://github.com/Eaglemann/askpdf-cli-ragColdPy
https://pypi.org/project/coldpyLVPilot
https://www.lvpilot.de/Berlinator
Hierarchical Image Annotation Tool Python
https://github.com/Eaglemann/Hierarchical-Image-Annotation-Tool-PythonCar Rental Web App
https://github.com/Eaglemann/Rentacar-Next.jsEnterprise Resource Planning System Java Swing
https://github.com/Eaglemann/Enterprise-Resource-Planning-System-JavaSwingEducation
Bachelor's Degree in Computer Science
Aleksandër Moisiu University of Durrës (UAMD) - Durres, Albania
Certifications
Astronomer Certification DAG Authoring for Apache Airflow 3
Astronomer
AWS Certified Solutions Architect
Coursera
Divide and Conquer, Sorting and Searching, and Randomized Algorithms
Stanford University | via Coursera
Python for Everybody
University of Michigan | via Coursera
IBM DevOps and Software Engineering
IBM
Skills
Libraries/APIs
React, Node.js, Pandas, NumPy, Pydantic, Plaid API, Requests, Playwright, REST APIs, OpenAI API, Redis Queue, Authorize.net, Stripe, AWS Amplify, Google Maps API, Claude API, Google APIs, SciPy, API Development, Financial Service API, Hugging Face Transformers, Beautiful Soup
Tools
GitHub, Celery, Amazon Elastic Container Service (ECS), Claude Code, Git, Figma, Claude, n8n, NGINX, Jira, SendGrid, Cron, AWS Copilot, Windsurf, Oracle ERP, AI Prompts, ChatGPT, Codex, Zapier, Microsoft Power Apps, Expo, Google Kubernetes Engine (GKE), AWS IAM, Amazon CloudWatch, Shadcn, Apache Iceberg, AWS CloudFormation, Terraform, Apache Airflow, Auth0
Languages
Python 3, TypeScript, JavaScript, SQL, Java, Python, XML, CSS, HTML, YAML, Snowflake, GraphQL, HTML5, Go, PHP, SQL DDL, C++
Frameworks
Django, Next.js, LangGraph, Tailwind CSS, Electron, Tauri, Scrapy, Flask, React Native, Agentic Frameworks, Angular, Express.js, Next.js 14, NestJS, Apache Spark, Selenium, Starlette, Trino, Swing
Paradigms
DevOps, ETL, Model Context Protocol (MCP), Event-driven Architecture, UI Design, Responsive Web Design (RWD), Microservices, Microservices Architecture, Automation, Clean Architecture, Dependency Injection, Role-based Access Control (RBAC), Testing, Real-time Systems, HIPAA Compliance
Platforms
Amazon Web Services (AWS), AWS Lambda, Linux, Amazon EC2, Docker, Vercel, Google Cloud Platform (GCP), Google Chrome, Kubernetes, Databricks, Medusa, CrewAI, Azure, Firebase, Netlify, AWS IoT, Shopify, Grok, Android, iOS, Microsoft Power Automate, SharePoint, Microsoft Power Platform, Microsoft Copilot Studio, Clerk, Cortex, Twilio, Apache Kafka, Ollama, Replit, Oracle, Oracle Integration Cloud (OIC)
Storage
PostgreSQL, Amazon S3 (AWS S3), RDBMS, Neo4j, MongoDB, JSON, SQLite, MySQL, Data Pipelines, Databases, Database Management, Google Cloud, Amazon DynamoDB, Firebase Realtime Database, Microsoft Entra ID, Google Cloud SQL, PostgreSQL 10, Hasura, Redis, Elasticsearch, ClickHouse
Industry Expertise
Cybersecurity
Other
FastAPI, Agentic AI, Large Language Models (LLMs), Cloud Infrastructure, LangChain, Profiling, Computer Science, Software Engineering, Cloud Computing, Amazon RDS, Algorithms, System Design, AI Architecture, RAG Architecture, AI Agents, Architecture, Orchestration, Pgvector, Multi-tenant SaaS, Row-level Security (RLS), Supabase, OpenAI, CI/CD Pipelines, AI Design, Artificial Intelligence (AI), AI Programming, APIs, Data Extraction, Minimum Viable Product (MVP), Workflows, Recommendation Systems, Engines, Scripting, Full-stack, Web Development, Data Processing Automation, Document Parsing, Financial Data, Page Speed Optimization, Retrieval-augmented Generation (RAG), API Integration, Multi-agent Systems, Vector Databases, Data Migration, RESTFul APIs, Large Language Model Operations (LLMOps), Web Scraping, Software Architecture, DevOps Engineer, Cursor AI, AWS DevOps, Gunicorn, Caching, Scaling, Security, GRC, CRM APIs, Data Transformation, Webhooks, Third-party APIs, Outreach, Railway, Dropshipping, CSS3 Animation, Distributed Architecture, AI Compliance Agents, Agentic RAG Systems, Trading, SOC 2, Fintech, Gemini, Pinecone, Trade Finance, OpenAI GPT-4 API, AI Automation, Enterprise Resource Planning (ERP), Generative Artificial Intelligence (GenAI), Supabase Auth, Code Review, Scalable Architecture, Cost Analysis, Costs, Financial Math, Calculators, Prompt Engineering, Full-stack Development, Data Scraping, Image Manipulation, AI Tools, AI-generated Code, Third-party Integration, Cloud, SaaS, Knowledge Management, AI Integration, Integration, Workflow Automation, CSV Import, full stack JavaScript, Localization, Payments, Big Data, Mobile App Development, Authentication, Middleware, Technical Leadership, Repository Pattern, Domain-driven Design (DDD), Spanish, Financial APIs, Machine Learning, Anthropic, Agentic AI Systems, Communication, Tailwind UI, eCommerce, Workflow Automation & System Integration, Multi-tenant Architecture, System Architecture, Data Engineering, Data Architecture, AI Chatbots, HIPAA, Real-time Data, Scraping, Data Security, AI Engineering, Solution Architecture, Data Science, Data Cleaning, Data Mining, Data Collection, Data Analysis, Code Auditing, Product Engineering, Web Scalability, Startups, Prototyping, Speech-to-Text (STT), Back-end, Software Development, RAG Systems, AI Agent Orchestration, Data Privacy, Startup Consulting, Technical Project Management, Fly.io, Production QA, Web Crawlers, LinkedIn Sales Navigator, Microsoft 365, Document Management, SharePoint Online, Identity & Access Management (IAM), GitHub Actions, Amazon Bedrock AgentCore, Back-end Development, Distributed Systems, Event-driven Systems, API Gateways, Memorystore, Microsoft Graph API, Office 365, Product Mindset, Agentic Deployment, Infrastructure as Code (IaC), Site Reliability Engineering (SRE), Machine Learning Operations (MLOps), AI Voice Agents, ElevenLabs Solutions, AI-assisted Development, LLM Integration, Legacy Code, Conversational AI, Security Architecture, Zustand, Amazon DocumentDB, Fractional CTO, CTO, Technical Architecture, Cloud Architecture, Scalability, System Architecture Design, Software System Architecture Development, Privacy, Reporting, Reports, Auditing, Audits, Financials, Financing, Software as a Service (SaaS), FinOps, Apache Superset, RAG Pipelines, Groq, Qdrant, CSS5, Polars, Sorting Algorithms, Directed Acrylic Graphs (DAG), Ontologies, Vibe Coding, OpenClaw, MinIO, ChromaDB, Milvus, Finance, Workday, Pub/Sub
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