Sergey Leschev Sergey Leschev

Sergey Leschev

FullStack Developer

Swift (L6+) | Full Stack (L6+) | Design Patterns (L6+) | System Architect (L7+) | Blog

Google Engineering Level: L6+

🏆 Awards

Ranking #Dev: Global TOP 200 (Certificate)

Sergey Leschev

Sergey Leschev

Languages: TypeScript, Shell, Database (T-SQL, PL/SQL, MySQL), Concurrency (Python3).

Algorithms: linked lists, binary search, hash table, queue/stack, dfs/bfs, sort, heap/hash, two pointers, sliding window, tree, greedy problems etc.

Golden Award for the Year of the Tiger Challenge

Sergey Leschev

Algorithmic skills: Dynamic programming, Greedy algorithms, Catepillar method, Binary search algorithm, Fibonacci numbers, Euclidean algorithm, Sieve of Eratosthenes, Prime and composite numbers, Maximum slice problem, Stack and Queues, Sorting, Time Complexity, Arrays, Prefix Sums, Leader, etc.

Contest: Algorithms, SQL, Data Structures, Bitwise operations (bit-ops), Frontend.

Tapping on a link will take you to relevant certificates.



Computer Science

React Custom Hooks (L6+)

useArray useAsync useClickOutside useCookie useCopyToClipboard useDarkMode useDebounce useDebugInformation useDeepCompareEffect useEffectOnce useEventListener useFetch useGeolocation useHover useLongPress useMediaQuery useOnlineStatus useOnScreen usePrevious useRenderCount useScript useStateWithHistory useStateWithValidation useStorage useTimeout useToggle useTranslation useUpdateEffect useWindowSize

Design Patterns (L6+)

Behavioral Creational Structural
🐝 Chain Of Responsibility 🌰 Abstract Factory 🔌 Adapter
đŸ‘Ģ Command 👷 Builder 🌉 Bridge
đŸŽļ Interpreter 🏭 Factory Method đŸŒŋ Composite
đŸĢ Iterator 🔂 Monostate 🍧 Decorator
💐 Mediator 🃏 Prototype 🎁 Facade
💾 Memento 💍 Singleton 🍃 Flyweight
👓 Observer ☔ Protection Proxy
🐉 State đŸŦ Virtual Proxy
💡 Strategy
🏃 Visitor
📝 Template Method

Project Guidelines (L6+)

A set of best practices in my projects.

Licenses & certifications

Latest Projects

[Web] Health & Fitness Web App

Role: Team Lead (L6+).

Description (tasks): Development architecture and new features.

Tech Stack:


I have a clear focus on time-to-market and don't prioritize technical debt. And I took part in the Pre-Sale/RFX activity as a System Architect, assessment efforts for Frontend (React-TypeScript) and Backend (NodeJS-.NET-PHP-Kafka-SQL-NoSQL). And I also formed the work of Pre-Sale as a CTO from Opportunity to Proposal via knowledge transfer to Successful Delivery.

🛩ī¸ #startups #management #cto #swift #typescript #database

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