Данило

Limassol, Cyprus

Danylo Boleyko [open contact info](look above in the "contact info" section)
[open contact info](look above in the "contact info" section)
Backend engineer building FastAPI services and reliable data pipelines. ​ [open contact info](look above in the "contact info" section)
I design clear APIs, cost-aware ingestion/orchestration (Prefect/Airflow), danylo-boleiko/
optimized data access (PostgreSQL/MongoDB/ClickHouse), and practical https://github.com/GrandMa
LLM-backed workflows. gus02

EXPERIENCE HARD SKILLS

ZENPULSAR, London — Back-End Developer Languages: Python (primary),
MAY 2022 – AUG 2025 TypeScript/JavaScript (for
full‑stack integration), SQL.
Built and maintained FastAPI services and data workflows powering
multiple products; integrated LLMs for summaries, Q&A, and sentiment Services & APIs: FastAPI,
classification; optimized pipeline performance and datastore access. For REST, WebSockets/SSE,
PUMP and SEMICONDUCTORS, delivered API endpoints, caching layers, and background jobs, caching,
charting data feeds; for QSIM, designed Prefect 2 orchestration with schema/validation, pagination.
retries/monitoring and a proxy‑free Reddit ingestion approach to cut costs
Data & Orchestration: Prefect,
while improving stability. Improved Airflow Reddit parsers ~5× and reduced
Airflow, Pandas, PyArrow,
MongoDB query latency with targeted index/aggregation changes. Tech:
pipeline design,
FastAPI, Python, Prefect 2, Airflow, PostgreSQL, MongoDB, ClickHouse,
retries/observability,
Pandas, PyArrow, Lightweight Charts data feeds.
cost‑aware ingestion.

​Datastores: PostgreSQL,
Clasta, United States — Back-End Developer
MongoDB, ClickHouse,
JUNE 2023 – MAY 2025 (part-time)
InfluxDB (read/metrics),
Built Quasar (Vue), introduced FSD architecture, created a flexible UI library
SQLAlchemy/SQLModel,
and decomposed complex components into smaller units, refactoring
indexing and query
business logic into clear modules to speed development and reduce defects.
optimization.
Tech: Quasar, Vue 3, Pinia, Vue-query.
​Testing & Quality: Pytest,
ESLint, Prettier, Ruff; typing
Freelance — Back-End Developer
and CI checks.
SEPTEMBER 2021 – MAY 2022

Delivered small web apps and lightweight APIs, focusing on clean data
models, simple authentication/validation, and reliable deployment for small
SOFT SKILLS
clients. Tech: Python/JS, Vue, FastAPI, SQL.

​Communication Skills: Verbal
and written communications.
EDUCATION
Interpersonal Thinking:
Empathy, Teamwork,
Institute of Engineering, National University, Zaporizhzhia
— Bachelor's Degree Collaboration, Conflict
resolution.
OCTOBER 2020 – MAY 2024

Bachelor’s in Software Engineering Critical Thinking: Research
skills, Decision-making,
 Creativity, Attention to detail.

Time Management:
PROJECTS Prioritization, Multitasking,
Goal setting, Productivity,
SEMICONDUCTORS — ZENPULSAR Meeting deadlines, Planning
Built backend services for an AI‑assisted news platform (Nuxt 3 frontend) and scheduling.
including summarization/Q&A endpoints, content pipelines, and caching
Customer and Client Service:​
for fast, stable daily updates; standardized response schemas and
Active listening to client needs,
pagination for downstream UIs. Tech: FastAPI, PostgreSQL/ClickHouse,
Patience.
caching, LLM integration.

QSIM — ZENPULSAR AWARDS
Designed the backend architecture and orchestration with Prefect 2 from
scratch (scheduling, retries, observability), implemented a proxy‑free Reddit Cisco Networking Academy​
ingestion flow to eliminate proxy costs, and built an LLM‑based sentiment - Cybersecurity Essentials;​
prediction pipeline that is more stable than the earlier PUMP setup. Tech: - CCNA: Switching, Routing,
Prefect 2, FastAPI, Python, Pandas, PyArrow, PostgreSQL/MongoDB. and Wireless Essentials;​
- CCNA: Introduction to
PUMP — ZENPULSAR Networks.

Refactored parser pipelines for readability and scale, optimized Airflow ICPC Foundation 22 Oct 2022​
Reddit parsers to run ~5× faster, and tuned MongoDB queries and indexes to Certificate of achievement.
lower latency; exposed data through FastAPI endpoints and prepared feeds
Brain Academy​
for analytics UIs; automated social ingestion and email with Airflow +
Certificate of Completion
Mailgun. Tech: Airflow, FastAPI, MongoDB, PostgreSQL, Mailgun.
“Basic programming

Lightweight Charts (Fork) — ZENPULSAR
Extended the library with gesture/mouse events and built a sentiment trend LANGUAGES
chart; shipped private plugins used by PUMP and SEMICONDUCTORS.
Ukrainian - Native​
English - Upper-Intermediate​
Clasta — Clasta
Russian - Freely
Defined backend API contracts, background processing patterns, and
module boundaries; transformed complex business rules into maintainable
FastAPI services with clear DTOs and validation, improving reliability and
onboarding speed. Tech: FastAPI, SQLModel, PostgreSQL.