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Alex
Safonov

Average Review
0.00
Reputation
24
Finished gigs
0
Finished jobs
0
Website
github.com
Country
Not specified
Skills
Web, Mobile & Software Dev
Javascript
QA
Python
SQL
Solidity
Smart Contract Development
Blockchain
Back End Developer
Databases
API
API Integration Specialist
Software Engineering
Functionality testing
Data Analysis
Docker
Rust
Automation
Documentation
Web3
Cryptocurrency
CI/CD
Debugging
Distributed Systems
Smart Contracts
Specialization
API & Financial QA | Python Backend & AI Integration
Hourly rate
$40/hr
About me
I build Python APIs and AI integrations, and help teams verify the workflows behind them. Hire me for: - A focused FastAPI/API integration with validation, error handling, logs and regression tests. - LLM tool workflows with structured outputs and server-side authorization. - Financial and backend QA: retries, duplicate requests, state transitions, balances and SQL reconciliation. My background includes financial-platform QA and banking/reporting systems. Public implementation examples: AgentProof (AI action authorization), NextRole (FastAPI and human-controlled decisions), and ContractGraph-QA (deterministic verification and evidence). See the portfolio for code and each project's scope. We start with one agreed workflow, clear acceptance criteria and a paid milestone. Deliverables can include implementation, regression coverage, findings and handover notes. Available 20-40 hours/week. Rate: $40/hour.

Work experience

Self-Employed / Independent
January 2026 – Current time
Job title
Independent Smart Contract Verification & QA Engineer
Work experience & achievements
Independent verification of smart contracts, financial state machines, AI-agent payment flows, and backend integrations. Focus areas: escrow, settlement, refund, dispute and cancellation lifecycles; exactly-once value movement; terminal-state correctness; authorization, replay protection, idempotency and concurrency; balance and fee conservation; temporal boundaries and transaction ordering; native regression testing and reproducible evidence. Created ContractGraph-QA, an open-source framework modelling actor → action → state transition → invariant → evidence. Applied Rust, Soroban, Solidity, Foundry, Python, JavaScript, REST APIs, SQL, GitHub Actions, stateful and invariant testing, and CI/CD to StreamPay, TrustLayer, Commitlabs, AgentProof-AI, Valta Pilot Lab and independent escrow assessments.
Freedom Finance Global / Tradernet
June 2022 – Current time
Job title
QA Engineer — Financial Platforms, Mobile & API
Work experience & achievements
Test financial and brokerage products across mobile, web, backend and API layers. Perform functional, integration, regression and release testing; validate trading processes, financial state, balances, records and downstream integrations; verify REST, HTTP, JSON and WebSocket contracts, errors and edge cases; use SQL and logs to investigate discrepancies; test mobile and web flows; prepare test cases, bug reports, acceptance criteria and release evidence; collaborate with developers, analysts and product teams. Technologies: REST APIs, WebSocket, SQL, JSON, OpenAPI, Postman, mobile, web and backend testing, Jira, Confluence and CI/CD.
Saint Petersburg Exchange
November 2018 – November 2019
Job title
QA Engineer / System Analyst — Exchange and Reporting Systems
Work experience & achievements
Tested exchange and financial reporting processes, backend calculations, SQL procedures, reports and data transformations. Investigated differences between requirements, stored data and generated reports; analysed functional and integration requirements; improved technical documentation and acceptance criteria; worked with architects, developers and business stakeholders; modelled processes and system interactions. Technologies: SQL, backend testing, financial reporting, API integrations, requirements analysis, BPMN, UML, Use Cases, Jira and Confluence.
FORA-BANK
November 2014 – November 2018
Job title
Reporting Systems Programmer / Banking Systems Specialist
Work experience & achievements
Developed, maintained and verified SQL-based banking reports and data-processing solutions. Validated banking operations and accounting data; analysed discrepancies and calculation errors; worked with exchange-traded and OTC financial instruments; supported reporting for promissory notes and banking products; tested changes in reporting and operational systems; investigated production data and prepared controlled corrections; translated requirements between business and technical teams. Technologies: SQL, banking systems, financial reporting, data analysis, reconciliation, OTC instruments and backend systems.

Education

Not specified
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