Libor Martinek
Verified Expert in Engineering
Python Back-end Developer
Brno, South Moravian Region, Czech Republic
Toptal member since March 11, 2022
Libor is a Python back-end developer with four years of experience, including several applications for cryptocurrencies and cybersecurity. He proposes, implements, and deploys solutions, is dedicated to his craft, and enjoys mentoring other developers. Libor's commercial experience is backed by a bachelor's degree in mathematics and physics.
Portfolio
Experience
- Python - 6 years
- Linux - 6 years
- Docker Compose - 5 years
- Functional Programming - 5 years
- SQL - 5 years
- PostgreSQL - 5 years
- Pytest - 5 years
- Docker - 5 years
Preferred Environment
Linux, Git, NeoVim Text Editor
The most amazing...
...thing I shaped and contributed to is a mentorship program for students learning programming from scratch—their "Aha!" moments are unforgettable.
Work Experience
Senior Software Developer
SandboxAQ
- Developed an application for use by in-house scientists as a source of truth that catalogues chemical compounds and tracks their appearance in experiments launched as part of internal data pipelines.
- Championed a testing strategy that runs against real deployment and in parallel with data closely matching reality. This led to many concurrency bugs being discovered and fixed, thereby strengthening trust in the system tremendously.
- Instrumented an automatic performance tracing of the application endpoints that led to discoveries of bottlenecks and inefficient database queries. Fixes improved stability and performance by several orders of magnitude.
- Spearheaded an initiative that led to the switch of the database engine, which did not require application downtime. This switch helped tremendously with sensitive data segregation, insufficient transaction isolation protections, and performance.
Back-end Software Developer (via Toptal)
SandboxAQ
- Developed a network traffic analyzer and an agent-based solution that captured traffic on a host machine, which could send the data to the back-end server for further soft real-time analysis.
- Led the efforts of introducing a means for increasing observability of the whole platform, including cross-correlation of distributed requests and performance monitoring.
- Conducted application and database profiling. Based on the results, I spearheaded the effort of optimizing the back-end server by several orders of magnitude.
- Created a suite of SQL scripts used for migrating all the data owned by a customer from a multi-tenant database to a dedicated instance just for them.
- Participated in several crises where resolution of the customer's asks was necessary as soon as possible, during which my proposed solutions and implementations were carried through to success.
Python Mentor
Software Development Academy
- Mentored aspiring students on their Python programming journey.
- Created interactive study materials for students' self-paced learning.
- Assisted students with their first real-world application development.
Back-end Developer
Crypkit
- Developed an app for managing and aggregating a cryptocurrency portfolio of an investment fund or a single user.
- Integrated 3rd-party APIs via providers or directly through specific cryptocurrency nodes.
- Evaluated cryptocurrency projects and APIs, prioritized their subsequent integration, and oversaw or directly implemented the solutions.
Back-end Developer
Braiins Systems
- Transitioned the project from a Python 2 to a Python 3 codebase.
- Maintained various cryptocurrency node clients and implemented new API methods.
- Implemented a system to monitor the duration of a user request and its subsequent analysis.
Back-end Developer
Blindspot Solutions
- Developed an application that aids security analysts during a security incident investigation.
- Handled client feature requests and was actively involved in the design specification and subsequent implementation.
- Implemented a testing infrastructure for performance checking and regression detection.
Experience
Bitcoin Node RPC Client
https://github.com/bibajz/bitcoin-python-async-rpcAedificator
https://github.com/bibajz/aedificatorEducation
Bachelor's Degree in Mathematics and Physics
Czech Technical University - Prague, Czech Republic
Certifications
Advanced Modeling for Discrete Optimization
The University of Melbourne | via Coursera
Cryptography I
Stanford University | via Coursera
Skills
Libraries/APIs
REST APIs, Asyncio, Flask-RESTful, SQLAlchemy, Sockets, GraphQL API
Tools
GitLab CI/CD, Docker Compose, Git, Pytest, Makefile, Terraform, RabbitMQ, Bazel, Vagrant, Wireshark, Tcpdump, Grafana, Shell, CircleCI
Languages
Python, Python 3, SQL, Scheme, Bash Script, Bash, GraphQL, MiniZinc
Frameworks
Flask, Django
Paradigms
Functional Programming, Test-driven Development (TDD), DevOps, Automation, Event-driven Programming, Concurrent Programming
Platforms
Docker, Linux, Amazon Web Services (AWS), Jupyter Notebook, Rancher, Debian, Google Cloud Platform (GCP)
Storage
PostgreSQL, InfluxDB, Redis, ArangoDB, JSON, NoSQL, Neo4j, SQL Performance
Other
Bitcoin, Property-based Testing, CI/CD Pipelines, HTTP, NeoVim Text Editor, APIs, FastAPI, Middleware, Version Control, Sanic Web Server, Async/Await, Podman, SSH, Prometheus, Optimization, TCP/IP, Transport Layer Security (TLS), Shell Scripting, OpenTelemetry, Cryptography, Discrete Optimization, Back-end, Trading, API Integration, WebSockets, Multiprocessing, Distributed Tracing, Structured Logging
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